Weedon Outlined

INDEX

1. Introduction to dermatopathology
   Dermatopathology terminology

Key dermatopathology diagnosis by topic
4.
TOPICS:
a. Lichenoid
b. Psoriasiform
c. Spongiotic
d. Vesiculobullous
• Immunofluorescence patterns
e. Granulomatous
f. Vasculopathic
g. Disorders of epidermal maturation and keratinization
h. Disorders of pigmentation
i. Disorders of collagen
j. Disorders of elastic tissue
k. Cutaneous mucinosis

1. Cutaneous deposits
   m. Diseases of cutaneous appendages
   n. Cysts and sinuses
   o. Panniculitis
   P. Metabolic and storage discases
   q. Miscellaneous
   I. Physical agents
   s. Infections and infestations
   t. Tumors of the epidermis
   u. Lentigines/nevi/melanoma
   V. Tumors of cutaneous appendages
   w. Tumors of fibrous tissue
   x. Tumors of fat
   y. Tumors of muscle/cartilage/bone
   z. Neural and neuroendocrine tumors
   aa. Vascular tumors
   bb. Cutaneous metastasis
   cc. Cutaneous infiltrates
   dd. Lymphoid and leukemic infiltrates
2. Histochemical stains
3. Immunohistochemical stains
4. Bodies/Other

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a. Layers

• Basal layer: single layer of cuboidal cells
• Spinous layer: several layers of polygonal cells with spines in
  between (desmosomes)
• Granular layer: one to several layers of flattened cells with a
  granular cytoplasm (keratohyaline granules)
• Cornified layer: flattened, anucleate keratinocytes in a
  ”basket weave” pattern; thicker on palms and soles
  b. Cells
• Keratinocytes: most of the cells of the epidermis
• Melanocytes: cuboidal cells with clear cytoplasm and eccentric
  nucleus in basal layer; 1 melanocyte per every 4-9 basal
  KCs
• Langerhans cells: look similar to melanocyte but at any level of
  Merkel celes is, antigen-presenting cells and dendritic
  layer but can’t really see on Hematoxyli
  & Eosin; type of neuroendocrine cell

2. Dermoepidermal Junction: aka basement membrane zone (BMZ) and appears
   as a thin pink (eosinophilic) band under epidermis; rete ndges (pegs)
   interdigitating with the dermal papillae
3. Dermis
   a. Layers

• Papillam i collagen in layer of dermis below epidermis made of
• Reticularmis mad of large ep argen demis under papillary
• Acid mact see on chand sustains ith Alcan bure anacid;
  c. Cells
• Mad balis friendly cells that made the heare no sent
  appearing cells that are concentrated

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multilobulated nucleus; not usually in normal skin
4. Subcutis (panniculus, subcutaneous fat): composed of lobules of adipocytes
(fat cells) separated by fibrous septa (made of collagen and contain blood
vessel and nerves)
5. Blood vessels (lymphatics are flattened so usually not seen in normal skin)
a. Layers

• Superficial plexus: arterioles and venules running at junction of
  papillary and reticular dermis
• Deep plexus: arterioles and venules running at junction of
  b. Structure: Small, dark endothelial cells surrounding the lumen

6. Pilosebaceous unit
   a. Hair follicle

• Shaft: composed of keratin
• Follicle: infundibulum (from opening at surface to sebaceous
  duct), isthmus (from sebaceous duct to insertion of arrector
  pili muscle) and inferior portion (below arrector pili)
  b. Sebaceous gland: cuboidal cells with basophilic cytoplasm at
  periphery of lobule and large, vacuolated cells in center; duct
  empties directly into hair follicle

7. Eccrine gland and duct
   a. Secretory gland: in deep dermis and subcutis
   b. Intradermal duct
   c. Intrepidermal duct: empties directly onto skin surface
8. Apocrine gland and duct
   a. Secretory coil: in subcutis; large lumen and decapitation secretion (tips
   bud off)
   b. Intradermal duct: empties into follicle above sebaccous duct

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Acanthosis: increased thickness of epidermis (spinous layer)
Apoptosis: dying cells with dark, condensed nucleus
Atypia: atypical appearance of nuclei found in malignant neoplasias
Ballooning degeneration: cytoplasmic swelling and vacuolization of keratinocytes (KCs)
Bulla: blister
Civatte (Cytoid or Colloid) bodies: homogeneous, eosinophilic round structures in lower
epidermis and upper dermis formed through degeneration of KCs
Crust: coagulated tissue fluid and plasma intermingled with inflammatory cells and KCs
Dyskeratosis: faulty and incomplete keratinization of KCs; shrunken with eosinophilic
cytoplasm and small, dense basophilic nucleus
Erosion: absence of epidermis but dermis intact
Exocytosis: lymphocytes in between cells of the epidermis
Epidermotropism: type of exocytosis where atypical lymphocytes permeate the
epidermis; seen in mycosis fungoides (type of cutancous T-cell lymphoma)
Fibrinoid necrosis (degeneration): deposition of eosinophilic fibrin
Giant cell: large, multinucleate cells; can be KCs or macrophages
Granuloma: reaction pattern with collections of lymphocytes, macrophages, and multi-
nucleated giant cells
Hydropic degeneration (baso vacuolar change): vacuolization of basal cells
Hyperkeratosis: increase in thickness of stratum corneum
Karyorrhexis: fragmentation of nuclei resulting in nuclear dust

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Necrobiosis: alteration of collagen so it looks smudged
Papillomatosis: epidermal and papillary dermal proliferation upward in irregular waves
or spires
Parakeratosis: incomplete keratinization with retention of nuclei in the stratum corneum
Pigment incontinence: deposition of melanin in the dermis as free particles or in
macrophages (melanophages)
Pleomorphic: variation of cellular and nuclear size and shape
Polymorphous: mixed inflammatory infiltrate (mixture of lymphocytes, eosinophils,
plasma cells, histiocytes, etc.)
Pyknosis: condensation of nuclear chromatin producing a dense, shrunken mass
Reticular degeneration: intracellular edema of KCs with retention of cells walls
producing a net-like appearance
Spongiosis: intercellular edema in the epidermis
Ulcer: absence of epidermis and part of dermis
Vesicle: small blister

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Toxic epidermal necrolysis
Lichen planopilaris
Lichenoid drug
Lichen planus
Lichen nitidus
Lichenoid keratosis
Lichen striatus
Lupus erythematosus
PSORIASIFORM
Lichen simplex chronicus
Pruirigo nocularis
Psoriasis
Guttate psoriasis
Pustular psoriasis
Pityriasis Rubra Pilaris
SPONGIOTIC
Stasis dermatitis
Pityriasis rosea
Seborrheic dermatitis
VESICULOBULLOUS
Dermatitis herpetiformis
Porphyria cutanea tarda
Pemphigus vulgaris
Pemphigus erythematosus / foliaceous
Bullous pemphigoid
Coma blister (sweat gland necrosis)
Epidermolysis bullosa acquisita
Epidermolysis bullosa
GRANULOMATOUS
Granuloma annulare
Interstito endome annulare
Sarcoid
Granulomatous rosacea
Suture granuloma
Keratin granuloma
Necrobiosis lipoidica diabeticorum
Tuberculosis
VASCULOPATHIC
Erythema annulare centrifugun
Pityriasis lichenoides chronica

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Atrophie Blanche
DISORDERS OF EPIDERMAL MATURATION/KERATINIZATION
Epidermolytic hyperkeratosis
Warty dyskeratoma
Porokeratosis
Hailey-Hailey
Darier’s disease (vs Grover’s)
Reactive Perforating Collagenosis (Kyrle’s)
Ichthyosis vulgaris
Granular Parakeratosis
DISORDERS OF PIGMENTATION
Incontinentia pigmenti
DISORDERS OF COLLAGEN
Lichen sclerosus ET atrophicus
Scleroderma / Morphea
Keloid
Scar (cicatrix)
Chondrodermatitis nodularis helices
DISORDERS OF ELASTIC TISSUE
Elastosis perforans serpiginosa
Pseudoxanthoma elasticum
CUTANEOUS MUCINOSIS
Follicular (alopecia) mucinosis
Pretibial myxedema
Myxoid cyst
Scleromyxedema (papular mucinosis)
Mucocele
Scleredema
Focal cutaneous mucinosis (myxoma)
CUTANEOUS DEPOSITS
Modular amidd
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CYSTS AND SINUSES
Steatocystoma
Bronchogenic cyst
Endometriosis
Proliferating trichilemmal cyst
Eccrine hidrocystoma
PANNICULITIS
Lupus profundus
Erythema nodosum
Alpha-1 antitrypsin deficiency
Pancreatic fat necrosis
Subcutaneous fat necrosis of the newborn
Sclerosing lipogranuloma (paraffinoma)
Sclerosing panniculitis (lipodermatosclerosis)
Erythema induratum (nodular vasculitis)
METABOLIC AND STORAGE DISEASES
Porphyria cutanea tarda
Glucagonoma
MISCELLANEOUS
Acanthosis nigricans
Accessory tragus
Supernumerary nipple
CUTANEOUS DRUG REACTIONS
PHYSICAL AGENTS
Polymorphous light eruption
Radiation dermatitis
Freeze artifact
Electrodessication artifact
Talon noir
INFECTIONS AND INFESTATIONS
Scabies
Herpes simples virus / Varicella zoster virus
Verruca plana
Tinea versicolor
Secondary syphilis
Tuberculoid leprosy
Lepromatous leprosy
Histo

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Tinea nigra
SSS
Impetigo (bullous)
Dermatophyte
TUMORS OF THE EPIDERMIS
Bowen’s
Adenoid squamous cell carcinoma
Morphea basal cell carcinoma
Clear cell acanthoma
Verrucous carcinoma
Basal cell carcinoma
Seborrheic keratosis, irritated and inflamed
Clonal seborrheic keratosis
Fibroepithelioma of Pinkus
LENTIGINES/NEVI/MELANOMA
Halo nevus
Balloon cell nevus
Spitz nevus
Melanoma in situ (lentiginous, superficial spreading)
Melanoma (lentiginous, superficial spreading type)
Pigmented spindle cell nevus of Reed
Recurrent nevus
Congenital nevus
Nevus of Ito/Ota
Cellular blue nevus
Nodular melanoma
Deep penetrating nevus
Blue nevus
TUMORS OF CUTANEOUS APPENDAGES
Pilomatricoma (+ ossification)
Trichofolliculoma
Trichoepithelioma
Trichilemmoma
Microcystic adnexal carcinoma
Desmoplastic trichoepithelioma
Nevus sebaceous
Sebaceous carcinoma
Eccrine poroma
Cylindroma
Eccrine spiradenoma

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Atypical fibroxanthoma
Giant cell tumor of tendon sheath (if in mouth = giant cell epulis)
Digital fibrokeratoma
Juvenile digital fibroma
TUMORS OF FAT
Angiolipoma
TUMORS OF MUSCLE/CARTILAGE/BONE
Leiomyoma
Angioleiomyoma
NEURAL AND NEUROENDOCRINE TUMORS
Merkel cell tumor
Granular cell tumor
Neurofibroma
Neurilemmoma (schwannoma)
Palisaded and encapsulated neuroma
Amputation neuroma (supernumerary digit)
VASCULAR TUMORS
Angiolymphoid hyperplasia with eosinophils
Glomus tumor
Intravascular endothelial hyperplasia (Masson’s)
Angiosarcoma
Kaposi’s sarcoma
Lymphangioma
Pyogenic Granuloma (Lobular capillary hemangioma)
Port wine stain
Microvenular hemangioma
Capillary hemangioma
Targetoid hemosiderotic hemangioma
Venus Lake
Arteriovenous malformation
Granulation Tissue
CUTANEOUS METS
Metastatic renal cell carcinoma
Metastatic breast cancer
Metastatic melanoma
CUTANEOUS INFILTRATES
Mastocytosis (Urticaria Pigmentosa or Mastocvtoma)
angerhans cell histiocytosi
uvenile xanthogranulom

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alteration; melanophages in upper dermis
Caspary-Joseph spaces: clefts at DEJ b/c of basal damage
Hypertrophic - infiltrate and changes at tips of rete ridges
Bullous - severe vacuolar alteration -> subepidermal blister
DIF - colloid bodies in papillary dermis stain for complement and IgM;
band of fibrin at basal layer
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lichenoid
Oral LP: no stratum corneum or granular layer. LP with plasma cells (ok in mouth)
Lichen planopilaris: keratotic follicular lesions
lichenoid infiltrate involving basal layer of follicular epithelium
perifollicular lymphs - infundibulum and isthmus / upper 1/3
+/- interfollicular lichenoid infiltrate
vs. lupus - no perivascular infiltrate
Lichen nitidus:
ball and claw (down growth of rete ridges)
small (1 or 2 papillae), primary infiltrate is histiocytic with pale
staining cells that blend into each other and lymphocytes; may see
DIF - negative
lichenoid
Lichen striatus:
lichenoid, +/- histiocytes occupying 3-4 adjacent papillae
lichenoid-spongiotic-psoriasiform
empty dermis with deep lymphocytic infiltrate around adnexa
(syringocentricity)
lichenoid
Lichen planus - like keratosis / Lichenoid keratosis:
lichenoid infiltrate, look lateral and usually see lentigo (pigmented basal layer) or
seb K
florid lichenoid reaction patter
shave biopsy
Lichenoid drug:
basal vacuolar change, cytoid bodies, parakeratosis/interruption of
granular layer, eosinophils, melanin incontinence (sun protected)

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шау progress to run tickness epidermal necrosis and
subepidermal bulla
*not EM because deeper infiltrate, PMN/eos, melanin
incontinence
interface (vacuolar) / intrapidermal
Erythema Multiforme:
lichenoid band obscuring DE jxn (lymphohistiocytic inf)
+/- spongiosis, ++ papillary edema (leads to vesiculation),
++ necrotic keratinocytes @ all levels (not just basal
layer), ni SC/no parakeratosis (Vs. PLEVA)
DIF - intraepidermal cytoid bodies (degenerate
keratinocytes), stain homogeneous pattern usually IgM,
sometimes C3; granular C3 @ DE jxn
interface / subepidermal
Bullous EM: subepidermal vesicle with lymphocytes, necrotic keratinocytes at all levels
of epidermis, nI SC
subepidermal
TEN:
confluent keratinocyte/epidermal necrosis (red)
SC preserved
subepidermal cell poor blister
minimal inflammation (EM inflam)
subepidermal
Graft-versus-host disease:
“mild EM”
satellite cell necrosis - lymphocyte associated apoptosis
acute
early chronic: lichenoid. like LP
Late chronic: sclerodermoid phase
fulminant: like TEN
-Grades: 0 nl, 1 basal vacuolar change, 2 dyskeratotic cells in
cpidermis/follicle and dermal lymphs, 3 clefts and microvesicles, 4
separation of dermis from epidermis but viable epidermis

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infiltrate
interstitial mucin / hyaluronic acid
follicular plugging
DIF
linear /granular “pearl necklace” IgM/IgG +/- C3 @ DEJ = lupus band
DLE - involved skin 50-90% +
SCLE - 60% +, fine IgG basal cells which correlates with Ro/SSA
SLE - involved skin 100% + / uninvolved skin sun
exposed 90% + / protected 30% + (? Prognostic)
NL controls 30% + if chronic sun
trunk less positives
lichenoid / interface (vacuolar) / intraepidermal / perivascular
Bullous SLE: subepidermal blister with PMNs = DH
DIE: lupus band

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*Spongiform pustules of Kogoj: PMNs in spinous layer / mid-
epidermis - SPECIFIC
regular epidermal hyperplasia with thin supra-papillary epidermis
increased mitosis in basal epidermis
pale 1/3 upper dermis esp. early; vascular dilatation and papillary edema

• plasma cells - HIV
  Pustular Psoriasis:
  *intraepidermal (mid), unilocular pustules
  PMNs migrate from dilated vessel in dermis to epidermis
  = Reiter’s
  Spongiform pustule: little collections within a large collection
  DDX: pustular psoriasis, candidiasis, geographic tongue
  (migratory glossitis, Reiter’s, acrodermatitis continua, syphilis
  Guttate Psoriasis:
  mounds of parakeratosis with PMNs +/- overlying orthokeratosis
  +/- spongiosis, +/- granular layer
  epidermal hyperplasia mild
  Pityriasis Rubra Pilaris:
  variable presentation
  multilayered scale (no PMNs) with alternating ortho
  and parakeratosis vertically and horizontallv
  hypergranulosis
  *follicular plugging / hyperkeratosis- diagnostic
  with parafollicular (lipping) parakeratosis
  psoriasiform hyperplasia but with acanthosis
  Lichen Simplex Chronicus / PN:
  compact ortho/hyperkeratosis
  some mild parakeratosis
  hypergranulosis
  irregular acanthosis
  elongated fibrotic dermal papillae / collagen in
  vertical streaks
  vs hypertrophic LP - lichenoid infiltrate and colloid bodies
  vs psoriasis - psoriasiform hyperplasia, dermal papillae not
  fibrotic, no granular layer, all parakeratosis with PMNs
  PN
  dx clinical
  pseudoepitheliomatous hyperplasia. often folliculocentric.

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Clinically = sunburn
Histology: Sun burn cells = apoptotic keratinocytes
Usually orals
Dose dependant
Photoallergic
Histology = allergic contact dermatitis
Usually topicals
Except for thiazides
May persist despite removal of allergen
Radiation Dermatitis
Epidermal atrophy
Telangiectatic blood vessel
Loss of adnexa
Hyalinized collagen - pink
Stellate fibroblasts
Burn
Electrical = Thermal
Epidermis with elongated keratinocytes
Homogeneous collagen
Freeze artifact - perinuclear bubble, pink
Air dry artifact - cells with clear center in epidermis
Crush Artifact
m/c in hematopoietic infiltrates

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1. Characterized by the presence of intracpidermal and intercellular edema
   (spongiosis).
2. Widened intercellular spaces between keratinocytes, with elongation of
   intercellular bridges.
3. Inflammatory cells are also present.
   Patterns of Spongiosis
4. Neutrophilic spongiosis (spongiform pustule): neutrophils within the
   spongiotic foci
5. Eosinophilic spongiosis: eosinophils in the spongiotic foci within epidermis
   (different than spongiosis with eosinophils)
   a. bullous pemphigoid > pemphigoid
   b. incontinentia pigmenti: dyskeratotic cells
   c. allergic contact dermatitis
   d. arthropod bites: superficial and deep perivascular infiltrate with
   eosinophils
6. Miliarial spongiosis: spongiosis centered on the acrosyringium (part of eccrine
   duct in the epidermis
7. Follicular spongiosis: spongiosis involving the follicular infundibulum
8. Classic spongiosis
   Neutrophilic Spongiosis (Spongiform Pustule)
   Pustular psoriasis and Reiter’s (see psoriasiform)
   IgA pemphigus (see vesiculobullous)
   Acute Generalized Exanthematous Pustulosis (AGEP; see vesiculobullous)
   Dermatophytosis and Candidosis
   Beetle dermatitis
   Eosinophilic Spongiosis
   I-Insect bite
   H-Herpes gestationis
   A—Allergic contact dermatitis (see below)
   P-Pemphigus
   P—Pemphigoid
   I-Incontinentia pigmenti
   E---Erythema toxicum neonatorum
   D-Drug reaction

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AVAVADEVIEV…
Follicular Spongiosis
Atopic dermatitis
Apocrine miliaria (Fox-Fordyce disease)
Eosinophilic folliculitis
Classic Spongiotic Disorders
Acute Dermatitis
Subacute Dermatitis
Irritant Contact Dermatitis
Allergic Contact Dermatitis
Nummular dermatitis
Seborrheic dermatitis:
Spongiosis centered around the hair follicle
Lipping parakeratosis of the follicular ostia
Atopic dermatitis
Pompholyx (Dyshidrotic eczema)
Juvenile plantar dermatosis
Stasis dermatitis:
Focal parakeratosis, mild spongiosis, and scale/crust
Proliferation of small, round, thick vessels in papillary
dermis
Hemosiderin and fibrosis
Pityriasis Rosea:
Mounding parakeratosis with underlying spongiosis
*Exocytosis of red cells and lymphocytes into epidermis
Perivascular lymphocytic infiltrate with extravasation of
Spongiotic Drug Reactions
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AVAVA EVE
…
• An early vesiculobullous lesion should be biopsied to ensure that a
histopathologic diagnosis can be made
• An accurate diagnosis of a vesiculobullous disease may be hampered by
regeneration of the epidermis or secondary changes such as infection or
ulceration.
• With respect to some blistering diseases, special techniques such as direct/indirect
immunofluorescence, and/or electron microscopy may assist in making a
diagnosis.
Three morphologic features that need to be assessed in the diagnosis of vesiculobullous
diseases include:
Anatomic level of the split
Subcorneal/intracorneal
Intraspinous
• Suprabasilar
Subepidermal
Mechanism responsible for split
Spongiosis = intercellular edema resulting in vesicle formation
• Acantholysis = loss of attachments between cells resulting in rounded,
detached cells within the blister cavity
Ballooning degeneration of keratinocytes = swelling of keratinocytes
secondary to viral infection leading to rupture of desmosomal attachments
btw cells and vesicle formation
*Important for subcorneal / intraepidermal
• Inflammatory cell component - predominant cell type both within blister cavity
and within the infiltrate in the underlying dermis.
*This applies mostly to subepidermal blisters.
”Blistering” disorders by anatomic level of split
Intracorneal & subcorneal blisters

1. Impetigo/bullous impetigo

Dermatophytosis/Candidosis
3.
4.
Pemphigus foliaceus
Subcorneal pustular dermatosis
5.
Acute generalized exanthematous pustulosis
_Miliaria crystallina
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13. Porphyria cutanea tarda
With lymphocytes:
14. Lichen sclerosus et atrophicus
15. Polymorphous light eruption
With eosinophils (Refer to’ I HAPPIED’ mnemonic):
16. Bullous pemphigoid
20. Arthropod bite reaction
With neutrophils:
17. Dermatitis herpetiformis
18. Linear leA bullous dermatosis
19. Bullous lupus erythematous
20. Sweet’s syndrome
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Intracorneal / Subcorneal
Impetigo - pms + bacteria
SSS - epidermolytic toxin
Subcorneal Pustular dermatosis - pustules sit on the epidermis
IgA pemphigus - pustules plus acantholysis, DIF - fishnet IgA, Desmocollin 1
AGEP - beta lactam and macrolide
Erythema toxicum neonatorum - cosinophils
Transient neonatal pustular melanosis - neutrophils
Pemphigus Foliaceus / Erythematosus
Path is the same: Acantholysis in upper epidermis, mixed with few pmns, dyskeratotic
cells ok

• Pemphigus Foliaceous = Fogo Selvagem
  DIF fishnet |gG/C3
  DSG 1 (160 kd)
• Pemphigus Erythematosus
  DIF fishnet IgG/C3 + lupus band
  Intrapidermal
  Spongiform pustule
  PPP
  Pustular psoriasis
  Impetigo herpetiformis = pustular psoriasis in pregnancy
  Arrodermatitie montinna

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Suprabasilar Blisters

1. Acantholysis
   P vulgaris
   P vegetans
   HH
2. Acantholysis + dyskeratosis
   Darier’s - Ca ATPase
   Grover’s
   Pemphigus Vulgaris
   P. vulgaris: tombstoning, upper epidermis tends to stay intact, no dyskeratosis
   Dsg 3 (130 kd)
   DIF: fishnet with IgG/C3
   IIF: fishnet on monkey esophagus only (moncy esophagus is the standard tissue used for
   indirect immunofluorescence)
   Pemphigus vegetans
   Is exuberant P. vulgaris
   Paraneoplastic Pemphigus
   Clinically like SJS
   Path: lichenoid and suprabasilar acantholysis
   250/230/210/190/170 kd
   DIF = fishnet IgG/C3 and linear granular BMA IgG/C3
   TIF: fishnet on monkey esophagus and rat bladder
   Hailey-Hailey
   Wet scale-crust in SC, no/mild dyskeratosis, dilapidated brick wall
   DIF negative
   Ca ATPase
   Subepidermal Bullous Diseases:
3. Epidermolysis Bullosa Acquisita: 25% eos / 75% neut
4. Bullous Pemphigoid: 75%eos / 25% neut
5. Porphyria Cutanea Tarda: cell poor with lymphs only

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Bullous Pemphigoid
Subepidermal Bullac with eos/neut
R/O DH, which can have large blisters, by looking at next papilla
DIF: linear BMZ + 1gG/C3
BP Ag 1 230 kd / BP Ag 2 180 kd (collagen XVII)
DH / Linear IgA / Bullous LE (EBA sometimes)
papillary neutrophilic microabscesses
DIF
DH: Granular igA >C3 in BMZ and at dermal papillae
Linear IgA / Chronic Bullous Disease of Childhood: IgA in linear pattern @
BMZ.
Bullous LE: Linear to granular IfG/IgA/C3
[Sweets has pseudo bullae]

ORESCENCE PATTERNS
substance (cell surface) Floor = Dermal pattern Roof = Epidermal pattern IG = linear granular
ns
higus
nis
pus Dz.
DIF
ICS IgG/C3
ICS |gG/C3 + LG BMZ IgM +/- IgG/C3
ICS IgA
ICS IgG/C3
Linear BMZ IgG/C3
NOT Autoimmune d/o!
NOT Autoimmune d/o!
NOT Autoimmune d/o!
SSS (@LL)
Linear IgG/C3 floor
Homogenous IgG and granular C3 in vessels / weak, thick linear BMZ
ICS IgG/C3 + LG BMZ IgG/C3
Colloid (cytoid) bodies IgM and IgA > IgG, Fibrinogen, shaggy BMZ
Linear BMZ. 1gG/C3.
Linear IgG/C3 roof
Same as BP. but more commonly only C3
Granular IgA>C3 in BMZ and papillae
Linear BMZ IgA
amphigoid
Linear BMZ IgG/lgA/C3
IgG/lgA/C3_(deep to A. Fibrils)
Anticpiligrin - floor / others - roof
Collagen IV/PAS
ICS esop!
ICS csopl
Roof of blister
Floor of blister
Floor of blister
Roof of blister
Increased in vessels and BMZ
NO
ICS esoph
Floor of blister
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Deep process - dermis or subcu
Fibrin in center of necrobiosis
Suppurative granulomas - composed of epitheliod histiocytes and multinucleated giant
cells with central collections of neutrophils; overlying pseudoepitheliomatous
hyperplasia; rule out infection
Foreign body granulomas - composed of epithelial histiocytes and foreign body-type
multinucleate giant cells (nuclei scattered around irregulariy)
Keratin granuloma:
corn flakes
Suture granuloma:
polarizable, braided
Miscellaneous granulomas
Interstitial granulomatous dermatitis / palisaded and neutrophilic granulomatous
dermatitis / Winkelmann or Churg-Strauss granuloma:
Interstitial infiltrate of lymphocytes, neutrophils, eosinophils, and histiocytes
Leukocytoclasis +/- vasculitis
Dermal collagen is basophilic

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Atrophie blanche:
Cryoglobulins:
3. In the Vessel
Microthrombi: Purpura Fulminans,
DIC, LA, Pro C/S, Anti-thrombin III
Def, Coumadin/Heparin Necrosis
Amorphous pink material: Cryos
= livedoid vasculopathy, segmental hyalinizing vasculitis
Fibrinoid material around vessels of SPV (“red crayon”)
+/- Thrombi
Vascular occlusive
Rule out EPP, which can look similar
Type II and III -> LCV
Type I: Amorphous pink material in vessels
Not much inflammation: mononuclear cells, rbcs
[If actual microthrombi think thromboembolic disease]
Vascular occlusive
Urticaria:
Acute and chronic perivascular and interstitial infiltrate
In differential of normal skin
Leukocytoclastic Vasculitis:
Erythema Elevatum Diautinum:
SVP vessels
Fibrinoid necrosis
Neutrophils and leukocytoclasis
RBC extravasation
Clinical - palpable purpura
Neutrophilic vasculitis
Neutrophils in the entire dermis
Perivascular fibrosis with neutrophils and
leukocytoclasis
Chronic neutrophilic vasculitis
Granuloma Faciale:
Grenz zone
Mixed infiltrate:
Plasma cells, histiocytes, eosinophils, pmns, lymphocytes
+/- vasculitis and perivascular fibrosis
Facial skin
Chronic neutronhilie vrecalitic

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Polyarteritis Nodosa: Neutrophilic vasculitis of medium sized arteries only (usually in
subcutaneous tissue)
Cutaneous and systemic form
Neutrophilic vasculitis
Sweet’s Syndrome:
Pseudobullae (papillary dermal edema)
Pandermal neutrophils with more debris than intact neutrophils
Not angiocentric
Neutrophilic dermatoses
Diseases with pseudobullae (severe papillary
dermal edema): threads of collagen

1. PMLE: sup and deep perivascular
   lymphocytic infiltrate
2. Sweet’s: neutrophils
   Erythema annulare centrifigum:
   perivascular lymphocytes “coat-sleeve” pattern
   Lymphocytic “vasculitis”
   Superficial and Deep Perivascular Infiltrate
3. LE - interface
4. Jessner’s
5. PMLE - papillary dermal edema
6. Gyrate Erythema
7. leukemia cutis
8. viral/rickettsial
9. puppp
10. drug
    Pityriasis Lichenoides Chronica:
    Mounding parakeratosis
    Subtle patchy lichenoid infiltrate
    Superficial perivascular lymphocytic infiltrate
    Rare RBC extravasation
    Lymphocytic “vasculitis”
    PLEVA:
    EM with parakeratosis and lymphocytic “vasculitis”
    Parakeratosis
    Dyskeratotic keratinocytes at all levels of the epidermis
    Lichenoid infiltrate

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Perniosis: Acral skin
Superficial and deep perivascular lymphocytic infiltrate
+/- interface change
Lymphocytic “vasculitis”
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Grover’s:
Acantholytic dyskeratosis
Basal layer intact
Eosinophils
”smaller areas involved”
Lateral - spongiosis -> only diagnostic one
Hailey Hailey: = Benign familial pemphigus
Wet - serum, scale, crust
Suprabasilar cleft
Acantholytic cells in cleft at all levels of epidermis (no dyskeratosis)
‘dilapidated brick wall”
Reactive Perforating Collagenosis (Kyrle’s): Central hyperkeratosis and parakeratotic plug
Invaginated atrophic epidermis
Collagen fibers in contact with keratin plug
Basophilic to eosinophilic debris being extruded
(not elastin; if VVG positive then EPS)
“volcano with huge opening”
Granular Parakeratosis:
Thick parakeratotic layer with retention of keratohyaline granules
Granular layer is preserved

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R/O allergic contact derm (no dyskeratosis and bullous
pemphigoid (adult skin)
Hypopigmentation

1. Abnormal migration/differentiation of melanoblasts
   a. Piebaldism
   b. Waardenburg
2. Destruction oF melanocytes
   a. Vitiligo
   b. Vogt-Koyanagi-Harada
   c. Chemical leukoderma
3. Reduced tyrosinase activity
   a.
   Oculocutaneous albinism type A
   b. ? phenylketonuria
4. Abnormal structure of melanosome
   a. Ash leaf spots of TS
   b. Chediak-Higashi
   c. Progressive macular hypomelanosis
5. Reduced melanization and/or numbers of melanosomes
   a. Albinism (tyrosinase positive)
   b. Griscelli
   c. Elejalde
   d. Idiopathic guttate hypomelanosis
   e. Hypomelanosis of Ito
   f. Ash leaf spots (non TS)
   g. Tinea versicolor
   h. Nevus depigmentosus
6. Reduced transfer to keratinocytes
   a.
   Nevus depigmentosus
   b.
   P. alba
   C.
   Postinflammatory leukoderma
   d. Tinea versicolor
   e. Chediak-Higashi
7. Abnormal vasculature
   Nevus anemicus

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3. punctate, reticulate (including whoris and streaks)
4. dyschromias
5.
Histopathology

1. basal hyperpigmentation
   .. epidermal change
   striking melanin incontinence
2. melanin incontinence and epidermal atrophy or dyskeratotic cells
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Stains:
Elastin - Verhoeff van Gieson
Calcium - von Kossa
Perforating Disorders:
EPS: Tiny papules with keratin plug and basophilic debris in a channel
Not as hyperkeratotic as RPC
Elastin - Verhoeff van Gieson
RPC: Volcano with huge opening and thick red collagen fibers being
extruded (=Kyrle’s)
Collagen - Trichrome
Perforating Folliculitis
Perforating GA
CNH+/- ulcer
Epidermal acanthosis at sides of defect
Kissing mature granulation tissue
Degenerative collagen with increased vasculature
Sometimes cartilage
LS&A
Vacuolar degeneration of basal layer
pale upper dermis from edema and homogenization of collagen
band of inflammation
normal collagen underneath
[more superficial than rad derm]
Plasma cells and lymphs especially at dermal/subcu junction, carly on, and more so in
R/O

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Alcian blue pH 2.5
Pretibial myxedema: Widening of collagen fibers with visible mucin in between, no
increased fibroblasts
Scleromyxedema (papular mucinosis):
Scleredema:
Increased mucin, increased collagen, and
increased fibroblast
(histologically similar to nephrogenic
fibrosing dermopathy)
Collagen bundles are slightly swollen and separated from one another
The reticular dermis is thickened
Must stain to see mucin
DDx: Normal back skin.
Digital mucous (myxoid) cyst:
Acral skin with fibroblasts and mucin in dermis. No
true cyst wall (joint extension)
Mucocele:
Mucosa, salivary glands
Mucophages present
May be ruptured with acute inflammation
Focal Cutaneous Mucinosis / Cutaneous Myxoma: Collection of mucin under DEJ with
fibroblasts
Follicular Mucinosis (Alopecia Mucinosa): Accumulation of mucin within the hair follicle
May have a periadnexal lymphocytic infiltrate
with eosinophils
Reaction pattern which can be associated with

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Calcinosis Cutis: purple clumps, von Kossa’s silver stain blackens deposits
(Ro PXE - purple squiggles)
Dystrophic - infantile calcinosis of the heel, dermatomyositis, sle, scleroderma,
in degenerating tissue or areas of trauma/scar, auricular
Idiopathic - scrotal calcinosis, subepidermal calcified nodule, tumoral calcinosis
Metastatic (Calciphylaxis) - hypercalcemia; diagnosis of exclusion
Ca deposition in media of arteries and calcifying panniculitis
Osteoma Cutis: pink clump with osteoclasts in lacunae
can be associated with calcinosis cutis
(look for ghost cells to r/o a calcified/ossified pilomatricoma
primary: congenital plaque like osteomatosis, multiple osteomas, military
osteomas
of the face, subungual exostoses, Albright’s hereditary osteodystrophy,
progressive osseous heteroplasia, fibrodysplasia ossificans progressive
secondary
Hyaline deposits
Gout: amorphous pink areas surrounded by foreign body giant cells
Deposits of needle-shaped, brown urate crystals which are doubly retractile
can be seen in alcohol fixed tissue
Amyloidosis: extracellular eosinophilic material in clumps (macular/lichen/nodular) or
around blood vessels and fat (systemic)
Fibrillar ultra structure
Stains:
congo red with apple: green birefringence in polarized light
thioflavine T: bright yellow-green fluorescence
crystal violet and methyl violet: stain metachromatically
Secondary

1. patients on HD - beta 2- microglobulin
   Familial - Iranstyrerin proatory disease - AA
   rnr.

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Juvenile type
Pigmented - hydroquinone related
Para colloid - colloid degeneration
eosinophilic material with clefting/separation artifact
fibroblasts at the edges of clefts
(t/o elastotic globules - found on sun damaged skin and have a
slightly basophilic tint)
Pigment and related deposits
Ochronosis: yellow brown bananas
Alkaptonuria (endogenous) - homogentisic acid oxidase deficiency resulting in
deposition of it on collagen fibers (skin and mucous membranes)
Exogenous (hydroquinone, phenol, picric acid) - hydroquinone / melanin
compound (localized skin)
Stain: methylene blue
Tattoos:
Lead - traumatic
Amalgam - mucosa, wiry black material in dermis
Hypersensitivity reactions - m/c red tattoo (mercury salts);
diffuse lymphohistiocytic infiltrate with eosinophils; look closcly for red
tattoo particles
Phototoxic reactions - yellow (cadmium)
Monsel’s (20% aqueous ferric subsulfate):
ferrugation of collagen fibers with
hemosiderophages (ie histiocytes with
Monsel’s inside

• Perl’s (iron) stain
  (r/o melanoma may be in the clinical ddx)
  Minocin Pigment:

1. generalized muddy brown - increased melanin in basal layer
2. blue-black pigmentation of scars - iron chelate (MCN and hemosiderin)
3. blue-gray pigmentation of legs - stains + for iron and melanin but
   histologically can look like hemosiderin
   Other denneiti

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H AVA V A E É
Carysasıs ’ gold, deposits around blood vessels, orange-red birefringence
Bismuth - “prurigo pigmentosa”
Phenothiazines — + melanin (female)
Amiodarone - Lipofuscin, + melanin and + Sudan black (male)
Blue-Black - ochronosis
Red-Blue skin and conjunctiva
Clofazimine - Frozen shows birefringent red crystals
Slate Gray
Localized
Mercury - large black aggregates in macrophages, around blood vessels, along
elastic fibers
Pretibial/Palate/Subangal
Antimalarials - + hemosiderin and + melanin
Bronze
Arsenic - normal “rain drops”
Melanin and arsenic deposit in dermis
Yellow
Quinacrine
Blue
Tetracycline - pigmentation of cutaneous osteomas
Blue line on Gingiva
Lead
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Trichotillomania/Traction Alopecia
Melanin casts within dilated hair follicles
Follicular units without shafts
Alopecia Areata
Peribulbar lymphocytes
Look in subcutaneous tissue for anagen hairs
’swarm of bees’
Acne Keloidalis
Naked hair shafts within dense inflammation
Scar/keloid formation
Pseudopelade
Very few hair follicles and no inflammation on scalp
End stage alopecia
Eosinophilic folliculitis
Folliculitis with mostly eosinophils
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Keratinous Cyst, Trichilemmal Type
From bottom portion of hair follicle
Like hair
No granular layer
Compact keratin
M/C on scalp
Proliferating Trichilemmal Cyst
KCT with proliferation of cyst wall
Thought to be “SCC” therefore complete excision is required
Older women on back of head
Vellus Hair Cyst
Small, multiple vellus hairs in center
Steatocystoma
Cyst with red cuticle
Sebaceous glands in wall
May be difficult to find
+/- Vellus hairs
Types:
Solitary
Multiplex
Associated with PC type 2
Eccrine Hydrocystoma
Simple cyst
Around eye - look for vellus hairs
2 cell layers:
Myoepithelial
Cuboidal
Apocrine Cystadenoma = Apocrine Hydrocystoma
Fruly an adenoma
Occurs anywhere on body
Cyst with multiple invaginations
Cuboidal cells with decapitation secretion

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Found at embryonic fusion lines
Pseudocyst of the Auricle
Not a true cyst because it has no lining
With in cartilage of ear
Can reoccur
Endometriosis
Fibrotic stroma
Glandular structures with central RBC in dermis
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• Scleroderma
  Lobular
• Nodular vasculitis
• Subcutaneous Fat Necrosis
• Alpha one antitrypsin deficiency
• Cytophagic histiocytic panniculitis = lymphoma
• Pancreatic panniculitis
• Lupus panniculitis
• Lipodermatosclerosis
• Sclerosing Lipogranuloma
  SEPTAL
  Erythema Nodosum
  Erythema Nodosum: Widened fibrous septae
  Giant cells in septae = Miescher’s granulomas
  May/may not have eos, neuts
  No vasculitis or necrosis
  LOBULAR
  Nodular Vasculitis
  = Erythema Induratum
  ”Vasculitis” at dermal-sc junction and in septa (small and medium vessels)
  Lobules with neutrophils -> fat necrosis => foamy macrophages
  Involves contiguous lobules
  R/O infection
  vs. PAN - large vessels in septa, restricted panniculitis
  Subcutaneous Fat Necrosis of the Newborn
• Sclerema Neonatorum
  Normal Dermis
  Needle like clefts in lipocytes
  +/- Giant cells in fat
  Pancreatic Panniculitis
  Focal areas in center of lohule

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Lymphoid follicles at edges of fat lobules
Nuclear debris from lymphs
+/- lupus changes on epidermis and dermis (50%)

• lupus band on DIF
  r/o subcutaneous panniculitis like T-cell lymphoma
  Lipodermatosclerosis
  = Membranous lipodystrophy / Sclerosing Panniculitis
  Stasis changes at the top
  Thick sclerosed septa
  Cystic degencration of fat = large holes
  Lipo membranous changes = feathery cuticle inside cysts
  Sclerosing Lipogranuloma
  = paraffinoma
  No deris or epidermis seen
  Disruption of fat cells with replacement by cystic spaces of variable size
  Cyst in fibrous tissue
  Chunk of deep tissue with swiss cheese look
  Alpha 1 antitrypsin Deficiency
  Pouring of neutrophils into reticular dermis and SQ septae
  Splaying of neutrophils between collagen bundles
  Dissolution of septae and dermis

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RVAVA..
Necrolytic Migratory Erythema (Glucagonoma)
Acrodermatitis Enteropathica
Both have identical path
Three layer epidermis:

1. Parakeratosis / Hyperkeratosis (pink)
2. Pale vacuolated keratinocytes (pale)
3. Normal epidermis (normal) —may have psoriasiform hyperplasia
   Diabetic Dermopathy
   Looks similar to stasis changes
   Blood vessel proliferation in superficial dermis with perivascular lymphocytes and
   hemosiderophages.
   PCT
   Subepidermal blister with few lymphocytes
   ”Caterpillar bodies:—elongated bodies or globules of basement membrane material and
   colloid bodies in the basal layer of the epidermis
   Thick BMZ around vessels-PAS positive and diastase resistant
   Festooning (more common b/e of thick vessels with BMZ but any subepidermal blister
   can have this
   Look for solar clastosis to differentiate from EPP
   DIF-IgG around upper dermal blood vessels
   Accessory Tragus
   +/- Cartilage in center
   Polypoid piece of tissue
   Central fat
   Rim of vellus hair
   Preauricular
   Supernumerary Nipple
   Epidermal thickening w/ mild papillomatosis and basal hyperpigmentation
   Central invaginated enlarged pilosebaceous unit
   Smooth muscle hyperplasia in the dermis
   Modified, deep, dark staining apocrine glands / ducts
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JAVAVA EVEN.
Type II collagen
Acanthosis Nigricans
Hyperkeratosis, papillomatosis and mild acanthosis
Basal keratinocyte pigmentation
No inflammation
Histology very similar to:
Subtype of epidermal nevus
Becker’s melanosis (nevus)
Associations: Insulin resistance and “malignancy”
Confluent and Reticulated Papillomatosis
Undulating epidermis with hyperkeratosis and low papillomatosis
Mild basal hyperpigmentation
Resembles AN but not as well developed
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Clinically = sunburn
Histology: Sun burn cells = apoptotic keratinocytes
Usually orals
Dose dependant
• Photoallergic
Histology = allergic contact dermatitis
Usually topicals
Except for thiazides
May persist despite removal of allergen
Radiation Dermatitis
Epidermal atrophy
Telangiectatic blood vessel
oss of adnexa
Iyalinized collagen - pink
Stellate fibroblasts
Burn
Electrical = Thermal
Epidermis with elongated keratinocytes
Homogeneous collagen
Freeze artifact - perinuclear bubble, pink
Air dry artifact - cells with clear center in epidermis
Crush Artifact
m/c in hematopoietic infiltrates

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2. Staphylococcal scalded skin syndrome (SSSS)
-Subcorneal cleft with acantholysis, sparse neutrophils and no bacteria
-Sparse mixed infiltrate
3. Erythrasma
-”Normal skin” differential
-Small coccobacilli in stratum corneum on Gram stain
4. Botryomycosis
-Basophilic granule (bacteria) surrounded by eosinophilic material (Splendore-
Hoeppli phenomenon) within an area of suppuration
5. Atypical mycobacterial infection
-acute abscesses, suppurative granulomas or poorly formed granulomas
-organisms stain with acid fast stain (red snappers) -look for them in cystic spaces
6. Leprosy
-Lepromatous leprosy: sheets of heavily parasitized macrophages and can look
Foamy (lepra or Virchow cells); clumps of acid-fast bacilli in macs (globi) -
Fite stain (acid-fast variant) may highlight them better
-Tuberculoid leprosy: non-cascating granulomas with epithelioid cells, Langhans giant
cells and lymphocytes; bacilli are rare
-Indeterminate leprosy: superficial and deep dermal infiltrate of lymphocytes and few
histiocytes around blood vessels, appendages and nerves; can usually find few
7. Rhinoscleroma
-Sheets of vacuolated macrophages (Mikulicz cells) containing Gram negative bacilli
best seen with Warthin-Starry
-Plasma cells with prominent Russell bodies (aggregates of immunoglobulin)
8. Secondary syphilis

• Variable histology
  -Lichenoid reaction pattern with plasma cells and endothelial cell swelling is classic

9. Bacillary angiomatosis

• Closely resembles a pyogenic granuloma with a lobular proliferation of blood vessels;
  however neutrophils are much more arminent in RA

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sign” (hyphae in between upper normal basket weave SC and lower
compact orthokeratotic or parakeratotic scale)
-Can have mild spongiosis and acanthosis
-Lymphocytic infiltrate +/- eos/neuts
2. Majocchi’s granuloma
-Perifollicular and dermal granulomas and mixed acute and chronic inflammation
-Fungal elements in follicle and in the dermis
3. Candidiasis
-Neutrophils in the stratum corneum

• Epithelium may demonstrate mild spongiosis and acanthosis
  -Budding fungal yeast forms

4. Tinea versicolor
   -Normal skin differential
   -Yeast forms and short hyphae in stratum corneum-can see well on H&E
5. Cryptococcosis
   -Epidermis may show ulceration or acanthosis
   -Acute and chronic inflammation w/ MNGCs
   -Can have a mucinous appearance due to the mucinous capsular material
   -Encapsulated yeast-like organisms
   -Cell wall stains with PAS, GMS or Fontana-Masson (also a silver stain)
   -Capsule stains w/ mucicarmine or Alcian blue
6. Blastomycosis
   -Epidermis can have pseudoepitheliomatous hyperplasia (CBS—-cocci, blasto,
7. Phacohyphomycosis
   -Circumscribed cyst or abscess in the deep dermis/subcutis
   -Brown filamentous hyphae and yeast forms present (as opposed to
   chromoblastomycosis in which brown, round sclerotic or medlar bodies
   are seen)

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1. Molluscum contagiosum

• Inverted lobules of hyperplastic squamous epithelium
  -Eosinophilic inclusion bodies (Henderson-Patterson bodies) within the
  keratinocyte cytoplasm

2. Herpesvirus infections
   -Histology of herpes simples, varicella and herpes zoster are very similar
   -Keratinocytes develop peripheral clumping (margination) of chromatin,
   homogenous ground-glass appearance, vacuolization of cytoplasm, and
   eosinophilic intranuclear inclusion bodies

• Intrapidermal vesicle forms from two types of degenerative change:
  a. Ballooning degeneration: affected keratinocytes swell and lose
  attachment to adjacent cells (acantholysis)
  b. Reticular degeneration: Progressive swelling of keratinocytes w/
  only fine cytoplasmic strands
  -Multinucleated keratinocytes may also be present
  -Can involve pilosebaceous units
• Vasculitis more common in zoster

3. Cytomegalovirus
   -Enlarged endothelial cells with intranuclear eosinophilic inclusions surrounded
   by a halo (owl’s eye)
4. Verruca vulgaris
   -Inward turning of elongated rete ridges
   -Columns of parakeratosis over papillomatous projections
   -Clumping of keratohyaline granules
   -Koilocytes: in superficial epidermis; small pyknotic nucleus surrounded by clear
   cytoplasm
5. Myrmecial wart
   -”Myrmecia”=anthill
   -Deep extensions of acanthotic epidermis
   -Large eosinophilic cytoplasmic inclusions
6. Verruca plana
   -Basket-weave hyperkeratosis and mild acanthosis

• Vacuolation of upper keratinocytes

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dyskeratotic cells
MISCELLANEOUS INFECTIONS/INFESTATIONS

1. Leishmaniasis
   -Viceration, hyperkeratosis, acanthosis
   -Dense dermal infiltrate of lymphocytes, parasitized macrophages, giant cells, and
   plasma cells
   -The organisms are round, basophilic, 2-4 micrometer is diameter, with eccentric
   kinetoplast, typically at the periphery of the macrophages (marquee sign)
2. Scabies
   Superficial and deep infiltrate with eosinophils +/- epidermal changes
   Burrow within the stratum corneum containing mite parts
3. Myiasis
   -Small cavity containing the developing larva with surrounding mixed infiltrate
   ontaining eosinophil
   Larva is surrounded by a thick chitinous cuticle with spine
   -Beneath the cuticle, layers of striated muscle and internal organs

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horn cysts (basket weave keratin), flat base
Clonal SK: whorls of bland, cytologically similar cells
Bowen’s Disease: parakeratosis, disorganized dyskeratosis
Clonal Bowen’s
Paget’s has mucin in cells which form glands and spare the basal layer
Melanoma in situ has no parakeratosis and involves the basal layer with an
increase of melanocytes
Acantholytic (adenoid) SCC:
Entire epidermis is involved
Keratinization at the base of the lesion
Dyskeratosis, atypia, acantholysis
Pseudo glands
BCC: connected to epidermis which is normal, nests of cells with peripheral palisading
cleft between tumor and stroma
Morpheaform BCC: Thick cords of basaloid cells in fibrotic stroma with mucin
Trichoepithelioma - no connection to epidermis, more Ca/Cysts,
*papillary mesenchymal bodies, cleft between dermis and stroma
Fibroepithelioma of Pinkus: thin anastomosing stands of basaloid cells
set in a prominent loose stroma
Verrucous CA:
large lesions with condyloma architecture
deep pushing bulbous projections, rare mitosis at bases

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Solar Lentigo:
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hyperpigmentation of bulbous rete ridges, “dirty feet”
MELANOCYTIC NEVI:
Deep Penetrating nevus:
small junctional component
Wedge shaped
Predominantly spindle cells with melanophages
Surround adnexa and nerves
Balloon cell nevus:
swollen melanocytes with clear cytoplasm and central nucleus
can have multinucleated cells
Halo nevus:
nevus with dense lymphocytic infiltrate which is diffuse
Band pushing up on a melanocytic lesion - worry about melanoma
Recurrent nevus:
scar under lentiginous melanocytic hyperplasia
look for residual nevoid melanocytes
indistinguishable from recurrent melanoma unless residual primary lesion
present
Spitz Nevus:
symmetric, hyperkeratosis, hypergranulosis, epitheliod and spindle cells
vertical nest with clefting on top, pale pink Kamino bodies
dermal melanocytes which are large and epitheliod infiltrate singly
increased vascularity
can be junctional, compound, dermal
Pigmented spindle cell nevus of Reed:
small, symmetric, spindles cells in fascicles
band of melanin at base
Congenital Nevus:
melanocytes extend between collagen bundles, nerves, vessels, and adnexa
5.7% risk of melanoma in giant >20cm congenital nevi
DERMAL MELANOCYTIC LESIONS
Nevus of Ito/Ota/Mongolian spot: dermal spindled melanocytes
Blue Nevus: spindled melanocytes with long dendritic processes and cytoplasmic melanin are
present between the collagen bundles

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AVAVADEVIEV…
Atypia of melanocytes
Symmetric, circumscribed, matures with depth
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MALIGNANT MELANOCYTIC PROLIFERATIONS
Breslow Thickness - from TOP of granular layer or ulceration to base of melanocytic
proliferation
MM, superficial spreading: asymmetric melanocytic proliferation with pagetoid spread
MM, Lentiginous (Lentigo maligna melanoma):
single small melanocytes at basal layer
extend down hair follicles
may form small nest
MM, Nodular:
nodular tumor
In situ component is present only above invasive component
MM, Desmoplastic
ddx of spindle cell neoplasm in skin
melanoma
scc
afx
leiomyosarcoma
dfsp
angiosarcoma
MM, Acrolentiginous

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Trichoepithelioma
Multiple nest of basaloid cells or interlacing pattern, symmetric,
1/3 connect to epidermis, clefi between stroma and epidermis, can
have cysts, look for abortive papillary mesenchymal bodies
Ddx: bcc
Desmoplastic Trichoepithelioma
linear cords and islands of basaloid cells in fibrous stroma,
keratinous cysts, FBGCR, and calcium
Ddx: morpheaform bec
INFUNDIBULAR / ISTHMUS TUMORS
Dilated Pore of Winer
Finger like projections from a dilated follicular pore
Inverted follicular keratosis
Endophytic tumor, basaloid cells at the periphery with larger
ceratinizing cells in the center
ook for squamous eddies at base
EXTERNAL SHEATH TUMORS
*Cowden’s
MATRICAL TUMORS
Pilomatrixoma
PERIFOLLICULAR MESENCHYME
Fibrofolliculoma / trichodiscoma

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u opena cous grcauy oumumoer scoaceous cels then consider CA
MALIGNANT - Sebaceous carcinoma
Multilobular tumor with basaloid cells > 50% with numerous mitoses
Some sebocytes centrally
Central necrosis

• Murri-Torre Syndrome
  APOCRINE TUMORS
  BENIGN
  Apocrine hidrocystoma (cystadenoma)
  Syringocystadenoma papilliferum
  Hidradenoma papilliferum
  Well circumscribed partially cystic structure with papillary areas
  Hidradenoma (acrospiroma)
  ipocrise vig ei non-encapsulated multilobular tumor, solid an
  vstic, two cell types: clear and cosinophili
  MALIGNANT
  Paget’s disease (extramammary)
  ale tumor cells at all levels of epidermis, glandular formatio
  rowd basal layer of epiderm
  PA25, olod-ion, FAst mucin (mucicarmine, Alcian bilue
  Imunohistochemistry - CEA+, EMA+, CK7+, AR
  Mucinous carcinoma
  Islands of epithelial cells in mucinous pools

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Eccrine Spiradenoma - blue ball in dermis, multilobular with thin fibrous
capsule, small basaloid cells admixed with larger paler cells, small ducts,
trabecular background
POROMA
Hidroacanthoma simplex — monotonous round cells with in epidermis
Eccrine poroma - monotonous round cells extend in cord from epidermis
into dermis
Dermal duct tumor - monotonous round cells forming islands in dermis,
duct-like structures are prominent
MALIGNANT
Microcystic adnexal carcinoma
top is syringoma / trichoepithelioma like, bottom is composed of
small cords of basaloid cells in a fibrous stroma
COMPLEX TUMORS
Nevus Sebaceous
Small hair follicles with sebaceous glands hanging off bottom, eccrine and
apocrine glands

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Angiofibroma: onion ring collagen around follicles
Round “punched” vessels
Increased fibroblasts
Clinical: adenoma sebaceum, fibrous papule, ppp, acral fibrokeratoma
Can have clear cell or granular cell variants
Acral Fibrokeratoma:
Polypoid, acral skin
Usually hyperkeratosis
Vertically oriented collagen
Increased fibroblasts and vessels
*no neural tissue (supernumerary digits)
Sclerotic Fibroma:
aka storiform collagenoma
Circumscribed dermal tumor
Laminated eosinophilic collagen bundles with clefting-”plywood”
Low cellularity
Pleomorphic Fibroma:
Dome-shaped
Spindle-shaped cells with prominent nuclear pleomorphism
Desmoplastic Fibroblastoma (Collagenous Fibroma):
Well-demarcated tumor in the subcutis but often peripheral infiltration
Hypocellular with large, stellate cells in a dense collagenous stroma
Nodular Fasciitis:
“Tissue culture appearance”—-plump spindle-shaped cells in a
haphazard array within a fibromyxoid stroma
Frequent mitoses
Extravasated RBCs and scattered lymphocytes
Solitary Fibrous Tumor:
Well-circumscribed tumors
Alternating hypercellular and hypocellular areas of spindle
cells
Staghorn vessels
Myofibroma: Infantile type or sporadic in adults
Biphasic pattern -Spindle cell proliferation in short fascicles as well as
round cells
Solarntio atrama no hualiniantion an lan manmia…
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Factor XIIIA +
DFSP:
AFX:
MFH:
Grows through to SQ, very cellular (spindle cells)
Traps individual fat cells in a “lacelike” pattern
Storiform or cartwheel pattern -sometimes around central vessels
CD34 +
Bednar tumor: pigmented variant; contains dendritic melanocytes
Atypical bizarre spindled cells and foamy multinucleated giant
cells fill the dermis
Mitoses common
No grenz zone
Normal or ulcerated epidermis +/- collarette
Some authors consider these reactive and not true neoplasms
Vimentin + and 50% are also CD68 +; CD10 may also be +
Deep APX, with much dermal component
1kcly many MFHs in past were undifferentiated sarcoma:
i variants: Pleomorphic (most common), Angiomatoid. Myxoic
Giant Cell, Inflammatory
Giant Cell Tumor of Tendon Sheath: Eosinophilic collagenous stroma
Round to spindled cells with vesicular nuclei
Multinucleated giant cells with up to 60 nuclei
Can see mitoses

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3 cells: large cells with multiple vacuoles (filled with ping-pong balls)
uni vacuolated cells
small cells with granular cytoplasm
Myxoid Liposarcoma:
Network of collapsed vessels - “Chicken wire appearance”
Mucoid stroma
Vacuolated lipoblasts and stellate cells
Very deep tumor
Leiomyoma:
Somewhat circumscribed non encapsulated tumor in dermis
ed-orange bundles of smooth muscle with whorled batter
igar shaped nuclei run in fascicle
Angioleiomyoma:
Deep red-orange nodular tumor
Collapsed vessels with thick walls of smooth muscle that merge
Sometimes no epidermis or dermis present
Leiom yosarcoma:
Spindled shaped cells with cigar-shaped nuclei - prominent mitosis
Nodular or diffuse pattern

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Solitary circumscribed neuroma (palisaded and encapsulated neuroma):
Located in upper dermis
Nerve fascicles without collagen in between
Well demarcated with clefting
Schwannoma (neurilemmoma):
Circumscribed, encapsulated tumor
Antoni A - cellular, fascicles, Verocay bodies
(picket fence nuclei)
Antoni B - acellular CT
NF:
wavy, delicate spindle-shaped nuclei and pink wispy stroma
+mast cells and small vessels
Granular cell tumor: Polyhedral cells with granular eosinophilic cytoplasm
Neuroendocrine Carcinoma (Merke] cell tumor):
small round blue cells with indistinct cytoplasmic boarders
Architecture: trabecular or grape like clusters
Nuclei: salt and pepper
Stains:
CK20 - paranuclear dot positivity
Chromogranin
Synaptophysin

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Types: Mibelli
Fordyce
Solitary and multiple
Circumscriptum
Fabry’s (corporis diffusum) - lamellar lipid bodies
AV Hemangioma: Large thick-walled vessels with fibromuscular wall
Microvenular Hemangioma: Thin uniform branching collapsed vessels
Targetoid Hemosiderotic Hemangioma: Small vessels with hobnail endothelial cells
Rbe and hemosiderin
Ddx: Kaposi’s sarcoma
ALHE:
Myxoid and fibrous stroma around vessels with plump endothelial cells (look epithelioid)
Lymphocytes (may form follicles) and eosinophils
Eosinophils on H+N: Granuloma Faciale or ALHE
Kimura’s: eosinophilic lymphogranuloma has same histology
LCH:
Lobular vascular proliferation with well developed collarette of epidermis
Fibrous septae separate lobules
No layering of rbe r/o Kaposi’s
May have pmns when ulcerates r/o bacillary angiomatosis
Bacillary angiomatosis:
Looks like loch with pmns but no ulceration
Organisms make purple granular clumps
Bartonella henselae >> quintana
Glomus tumor:
Rounded monotonous cells with eosinophilic cytoplasm and dark round nuclei
Several layers thick around vessels - Glomangioma
Mostly cells - Glomus Tumor
Intravascular papillary endothelial hyperplasia: (Masson’s tumor, organizing hematoma)
Papilay chandels verei coldethel a combus surrounded by vessel wall
Kaposi’s sarcoma:
Irregular jagged slit like vascular spaces

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Edematous background
Vessels engorged by rbc
Neut, plasma, lymphs, histiocytes
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Breast Cancer Met
Linear cords of cells that touch and can form glandular structures
”Indian file”
Usually less cellular than leukemia cutis
Malignant Melanoma Met
Dermal tumor with nesting and focal areas of pigment
Frequent mitoses

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Cells have granular cytoplasm
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LCH
Epidermotropism of large cells
Cells are large with kidney shaped pale nuclei
Dermal edema with cells floating
Can have eosinophils associated
JXG
Touton giant cells (wreath with surrounding foam)
Dermal tumor of mononuclear cells
Eosinophils and lymphocytes also present
Xanthelasma
Thin epidermis with many small hair follicles
Mononuclear cells with foamy cytoplasm/lipid in all cells
Lipid can be extracellular
Reticulohistiocytic Granuloma
Giant cells with pink ground glass cytoplasm

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Subtype of Cutaneous T-cell lymphoma
Collections of lymphocytes in epidermis with minimal spongiosis
= Pautrier microabscesses
Lymphocytes line up at the DEJ but do not obscure
’pearl necklace’
Lymphocytes are larger, have a cerebriform nuclei and a clear perinuclear halo
CD3+/CD4+ / CD7 decreased /CD8-/CD30-
Clonal aß TCR gene rearrangements
Classic type patch to plaque to tumor (Alibert-Bazin type)
Other subtypes of CTCL with distinctive histologic and clinical findings:
Folliculotropism mycosis fungoides, pagetoid reticulosis (Woringer-Kolopp disease),
granulomatous slack skin, Sézary syndrome
LYP (type A)
Wedge shaped infiltrate with eosinophils, neutrophils, large mononuclear cells
Large mononuclear cells have anaplastic morphology (bizarre, chunks of coal)
CD3+/CD4+/CD30+
r/o PLEVA - look at sides for dyskeratotic keratinocytes
r/o lymphoma (primary cutaneous anaplastic large cell lymphoma = C-ALCL)
which would fill dermis and not have a mixed infiltrate
C-ALCL is ALK t (2; 5) negative and epithelial membrane antigen
negative; these are markers pr primary systemic anaplastic large cell
lymphoma
*One of the primary cutaneous CD30+ lymphoproliferative disorder:
• Common histologic feature: large atypical lymphoid cells CD30+
• CD30 is a transmembrane cytokine receptor to TNF receptor
family and is expressed by activated lymphocytes
possible on histology alone
Cutaneous Lymphoid Hyperplasia
*Pseudolymphoma / lymphadenosis benigna cutis / lymphocytoma cutis /
cutaneous lymphoplasia’
Classically simulates B-cell Imhoma

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Leukemia Cutis
Grenz. zone
Atypical mononuclear cells with kidney bean shaped nuclei with frequent mitoses
percolate through collagen -‘indian file’ of individual cells
Similar to lobular breast carcinoma
Most often seen in acute mycloid leukemia: FAB type M4 and M5
Usually lysozyme, myeloperoxidase, CD68 positive
Cutaneous B-cell lymphoma
”Lymphoma cutis’
Cutaneous follicle center cell lymphoma and primary cutaneous marginal zone B-
cell lymphoma represent 90% of all forms of cutaneous B-cell lymphoma
Share similar clinica presentation, response to TX, and great prognosis
Other important cutaneous B-cell lymphomas are:
Primary cutaneous diffuse large B-cell lymphoma, leg type
Primary cutaneous diffuse large B-cell lymphoma, other
Epidermis is normal
Grenz zone
Nodular to diffuse infiltrate that fills dermis and extends into subcutancous tissue
Mononuclear cell infiltrate with mitoses
Crush artifact
PCR for IgH present in 50% of cases (also 10% of cutaneous lymphoid
hyperplasia)

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can Die, PH 2. - acid MI’S (hyaluronic acid), blue
Alcian blue, pH 0.5 - Sulfated MPS, blue
Alizarin red-S - calcium, orange-red
Bodian - nerve axons, black (silver stain)
Colloidal iron - acid MPS (hyaluronic acid), blue
Congo red - amyloid, pink-red with green birefringence in polarized light
Crystal violet - amyloid, metachromatically purple-red
Dieterle and Steiner - spirochetes, bacillary angiomatosis; black (silver stain)
Fontana-Masson - argentaffin-melanin; black (ammoniated silver stain)
Giemsa - mast cell granules, acid MPS, myeloid granules, Leishmania, Donovan bodies, Histo,
Rickettisa; metachromatically purple
Gomori’s iron reaction (Prussian blue/Perls) - iron, blue
Gomori methenamine silver (GMS)- fungi (live and dead), Donovan bodies, Frisch bacilli
(rhinoscleroma); black (silver stain)
Gram stain ( Brown and Brenn, Gram-Wigert, MacCallum-Goodpasture) - bacteria, gram
positive blue and gram negative red
Hematoxylin-cosin - routine
Masson trichrome - collagen is blue or green and muscle is red
Mucicarmine - epithelial mucin, cryptococcus capsule; red
Napthtol-AS-D chloracetate esterase (Leder) - mast cells, neutrophils, myelocytes; granules
stain red
Oil red O - lipids, red, fresh tissue
Osmium tetroxide - nerve myelin, black; used mostly in electron microscopy
Periodic Acid-Schiff - glycogen (red - diastase liable), neutral MPS, fungi (only living),
basement membrane; red
Peris potassium ferrocyanide (Prussian blue) - hemosiderin (iron), blue
Phosphotungstic acid-hematoxylin (PTAH) - fibrin, deep blue and muscle, blue to purple
Prussian blue (Perls)- iron, blue
Scarlet red - lipids, red, fresh tissue
Thioflavin-T - amyloid, blue-green with fluorescent microscope
Toluidine blue - acid MPS, blue
Turnbull blue (very similar to Perls’ Prussian blue) - iron, blue
Verhoeff-van Gieson - elastic fibers, black (collagen red)
Von Kossa - calcium, black
Wade-Fite (modified AFB—sections soaked in xylene-peanut oil first) - M. leprae, red
Warthin-Starry - spirochetes, Donovan bodies; black (silver stain)
Weigert’s resorcin-fuchsin - elastic fiber, violet

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CAM 5.2
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AEI/AE3
CK-20
CK-7
Epithelial
membrane antigen
(EMA)
Carcinoembryonic
antigen (CEA)
BerEP4
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Cocktail of low molecular weight anti-keratin
antibodies
Cocktail of low and high molecular weight anti-
keratin antibodies
Anti-cytokeratin antibody
Anti-cytokeratin antibody
Glycoprotein located in secretory
mammary cells
Normal protein product of the goblet cells found in
small and large intestines
Epithelial antigen antibody
Poorly differentiated neoplasms of
epithelial origin; doesn’t stain SCC of
Poorly differentiated neoplasms of
epithelial origin; does stain SCC of skin
Merkel cell carcinoma (perinuclear dot)
Paget’s disease
Extramammary Paget’s disease, eccrine
neoplasms, sebaceous carcinoma
Metastatic adenocarcinoma,
extramammary Paget’s and eccrine
neoplasms
(+) BCC, (-) SCC
Il.
Mesenchymal Differentiation Markers-neoplasms of mesodermal origin; connective tissuc, blood and
lymphatic vessels
Marker
| Description
Used for
Desmin
Intermediate filament
Smooth
Neoplasms of muscle origin striated
Contractile protein
Muscle
Myofibroblasts and myoepithelial cells;
tumors of muscle
Actin
(SMA/
Actin)
HHF35
7GFA1
CD31
CD34
Vimentin
Muscle-specific actin
Smooth muscle specific actin
Terminal marker of endothelial cells
Located on hematopoietic progenitor, vascular
endothelial cells, and outer root sheath of follicle
Stains a type of intermediate filament found in
mesenchymal and some ectodermal cells
Leiomyosarcomas, rhabdomyosarcomas
Myogenic sarcomas
Angiosarcoma
Dermatofibroma vs DFSP (DFSP is +),
nephrogenic systemic fibrosis,
trichilemmoma, leukemia cutis
Ubiquitous— stains sarcomas, lymphomas,
melanoma and some spindle cell carcinoma
III.
Marker
S-100
NSE
HMB-45
MART-1
Malan A
Neuroectodermal Differentiation Markers
Description
Family of calcium channel blocking proteins
Neuron Specific Enolase
Component of premelanosome vesicle.
/elanoma Antigen Recognized by CD8+ I cells; use
TUsed for
Melanocytic tumors, neural tumors, granula
ell tumor, cutaneous Rosai-Dorfma
Lieur, home, Merke el carcinoma
Melanoma (not desmoplastic)

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CD8
CD7
CD10
CD138
BCL-2
BCL-6
Myeloperoxidase
(MPO)
Lysozyme
к and 2 light
chains
CD30 (Ki-1)
CD68 (Kp-I),
Factor XIIIa
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Stains suppressor T-cells
T-cell marker
Stains follicle center cells and myoepithelial cells
Plasma cells
Stains T-cells and neoplastic B-cells (anti-
apoptotic)
Stains follicle center cells
Stains granulocytes
Stains histiocytes and myeloid cells
Mature B cell and plasma cell markers, normal
ratio is 3 to 1
Activated T and B cell marker
Lysosomal component in lung macrophages
Coagulation factor
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T-cell Lymphomas
T-cell lymphomas
Can be lost in T-cell lymphomas, especially
Sézary syndrome
Follicle center B-cell lymphoma, AFX
Plasmacytomas
Follicle center B-cell lymphoma; BCC
(diffuse pattern) vs trichoepithelioma
(outermost epithelial layer)
Follicle center B-cell lymphoma
Leukemia cutis
Leukemia cutis
B-cell lymphomas
Lymphomatoid Papulosis and anaplastic
large cell lymphoma
Marker for histiocytes (60% AFX)
DF (+), DFSP (-)
V.
Marker
CDIA
Langerin
CD56
Ki-67 (MIB 1)
Procollagen 1
Additional Specific Markers
Description
Langerhans’ cell marker
Langerhans’ cell marker (Birbeck granules)
Natural killer cell marker
Proliferation marker
Used for
Langerhans’ cell histiocytoses
Langerhans’ cell histiocytoses
NK and NK/T-cell lymphomas
AFX

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Asteroid bodies: acidophilic, pink
stellate inclusions composed of collagen
with radiations in giant cells /
granulomas; disease associations:
sarcoidosis, berylliosis, tuberculosis,
sporotrichosis, granulomatous infiltrates
leprosy
Birbeck granules: “tennis racket”-shaped
granules in cytoplasm of Langerhans’
cells (histiocytosis X)
Banana bodies: content is Schwann
cells; disease associations: Farber
lipogranulomatosis (EM), ochronosis
Caterpillar bodies: pink necrotic
material in blister roof in epidermis in
PCT
Civatte (hyaline/colloid/cytoid) bodies:
necrotic keratinocytes seen in LP,
GVHD, amyloidoses, interface
dermatitis, lupus, poikiloderma
Cigar bodies: budding cells in
Sporothrix
Comma bodies: Seen in benign cephalic
histiocytosis, sinus histiocytosis LCH,
congenital self-healing
reticulohistiocytoma, JG
Councilman bodies: cytoplasmic
inclusions with cellular remnants seen in
BCC and amyloid
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rarver upogranulomatosis (EM)
Dohle’s inclusion bodies: small coccus-
shaped bodies occurring in the
polymorphonuclear leukocytes of the
blood in several diseases especially
scarlet fever
Donovan body: intracellular bacillus
(Calymmatobacterium granulomatis)
seen in histiocytes in the genital skin of
patients affected with granuloma
inguinale
Dorf balls: pink amorphous globules in
vessels seen in Kaposi sarcoma
Dutcher bodies: “intranuclear”
inclusions of immunoglobulin in
plasmacytoid cells
Farber bodies: Farber
lipogranulomatosis (EM)
Flame figures: degranulated eosinophils
surrounding altered collagen seen in
Wells, BP, eczema, dermatophyte,
arthropod, and dermal hypersensitivity
Floret giant cells: pleomorphic lipoma
Gamma-Favre bodies: small
intracytoplasmic inclusion bodies found
in lymphogranuloma venereum
Glomus bodies: regulated arteriovenous
anastomoses in the skin that play a role
in thermoregulation

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Paschen bodies: variola virus in
Smallpox
Papillary mesenchymal bodies: blue
islands with cap of differentiated stoma
and condensation of blue cells (ball and
claw) seen in trichoepithelioma
Physaliferous cells: very large tumor
cells with bubbly vacuolated cytoplasm
(some glycogen) and vesicular nuclei,
seen in chondromas
Psammoma bodies: a spherical,
concentrically laminated mass of
calcareous material, usually of
microscopic size; such bodies occur in
both benign and malignant epithelial and
connective-tissue tumors, and are
sometimes associated with chronic
inflammation; seen in: nevocellular
nevus, cutaneous meningioma, thyroid
papillary cancer, ovarian cancer and
endosalpingiosis
Pustuloovoid body of Milian: Granular
cell tumor
Residual bodies: pink globules in
cytoplasm compose of a collection of
lysosomal granules seen in Granular cell
tumor and Sarcoid
Rocha-Lima bodies: endothelial pink-
purple cytoplasmic inclusions seen
Verruga peruana
Russell bodies: cytoplasmic
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Granuloma inguinale
Schaumann bodies: concentrically
laminated calcified inclusions (up to 50
um) in giant cells seen in sarcoidosis,
tuberculosis, granulomatous infiltrates,
leprosy and berylliosis
School of fish: seen in culture/smear of
Haemophilus ducreyi in chancroid
Smudge cells: cell with a large, ovoid
nucleus filled with a granular
amphophilic to deeply basophilic mass
and an indistinct nuclear membrane;
seen in adenovirus-infected cells
Sulfur granules: yellow foci of
Actinomyces
Sucquet-Hoyer canals: shunts of glomus
bodies, involved in thermal regulation
Tactoid bodies: whorled nerve-like
body in a nevus
Tingible bodies: macrophages with
blue-gray appearance seen in lymphoid
follicles of cutaneous lymphoid
hyperplasia
Verocay bodies: palisades of nuclei at
he end of a fibrillar bundle in
chwannoma (neurilemoma) Antoni,
Virchow cells: foamy histiocytes with
globi of organisms in leprosy

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cells containing von Willebrand factor
(EM)
Winkler’s bodies: spherical bodies seen
in the lesions of syphilis
Zebra bodies: endothelial cells seen in
Farber disease lipogranulomatosis (EM)
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