SKIN PATHOLOGY

CUTANEOUS PATHOLOGY

MELANOCYTIC LESIONS

PIGMENTATION/MELANOCYTIC DISORDERS

VITILIGO

• § Irregular, WC
• § All races but more in dark skinned
• § Wrists, axillae, periorall, periorbital, anogenital

Mechanism

• § AI[1]
• § Neurohumoral factors
• § Toxic intermediates in melanin synthesis

Micro

• § Loss of melanocytes[2]
• § Childhood
• § Macules, after sun exposure
• § Cyclic with summer and winter

FRECKLES (ephelis)

Micro

• § Normal number but increased melanin in basal keratinocytes
• § Mask-like facial hyperpigmentation, worse with sun exposure, fades postpartum
• § Hyperestrogenic states

MELASMA

Mechanism

• § Increased melanin transfer

Micro

• § Epidermal type: increased melanin in basal layers
• § Dermal type: melanin incontinence
• § Benign hyperpigmentation, skin or mucosa
• § Infancy and childhood
• § Not darkened with sun exposure[3]
• § Unknown etiology

LENTIGO

Micro

• § Lentiginous basal hyperpigmentation due to melanocyte HP

TUMORS

NEVI

• § Usually acquired
• § ≤0.6cm
• § Lentigo simplex=first phase in evolution of common nevus

Mechanism

• § Basal cells become melanocytes[4]à junctional nevi (nests)à compound nevi (nests and cords in dermis)à dermal nevi
• § ▪< 1cm, upper extremities
• § ▪ heavily pigmented nodule in deep dermis
• § ▪ pig’t in melanophages
• § ▪1-3cm, lower back and buttocks
• § ▪ unpigt. spindle cells with intervening rare
• § ▪ melanophages, well circ.
• § Clin: kids, face and legs, red, small
• § Micro: junctional, compound, intradermal
• § ▪ spindle or epithelioid cells
• § ▪ symmetry
• § ▪ maturation
• § ▪ Pagetoid spread
• § ▪ junctional “Kamino bodies” (red globules) on BM
• § ▪ vertical clefting “raining down” look
• § ▪ random atypia

COMMON BLUE NEVUS

CELLULAR BLUE NEVUS

SPITZ NEVUS

DYSPLASTIC NEVUS

Clinical

• § Young adults, ”dysplastic nevus syndrome”

Micro

• § Usually compound type
• § architectural changes:
• § >5mm
• § Shoulder: epidermal component extends beyond the lateral margin of the dermal component
• § Fusing of tips of rete ridges
• § Horizontally oriented spindle cells
• § “Random atypia”
• § Lamellar fibrosis and perivascular infiltrate

Features that help ddx from melanoma***

• § Atypia is not anaplastic
• § “Random atypia”→atypical cells are scattered with nevomeloncytes
• § No ”discohesive infiltration” of the epidermis
• § Pagetoid spread at edges
• § Mitoses deep in dermis
• § Invasive component

MELANOMA

Clinical

• § Young adults, ”dysplastic nevus syndrome”

RF

• § Sun-exposure as kid
• § Family history (p16)
• § Dysplastic nevi

Subtypes (clinical and micro for each)[5]

lentigo maligna[6]

• § Face, elderly, not fatal, assoc/ sun-exposure
• § Solar elastosis, only single cells into the dermis, atrophic dermis

superficial spreading

• § “ABCD”, middle aged
• § Elevated nodule assoc/ deep invasion, marked cytologic atypia, pseudoinclusions, grooves, large eosinophilic nucleoli

nodular melanoma:

• § Younger, higher mets due to vertical growth phase
• § Smooth nodule covered by normal epidermis. no radial growth phase

acral lentiginous melanoma

• § Blacks and Asians
• § Intraepidermal lentiginous component like lentigo maligna, but melanocytes are bizarre

desmoplastic melanoma

• § Spindle cells with desmoplastic dermis
• § Intense lymphocytic host response
• § S100 +; but HMB45&MelanA –
• § Ddx: hypertrophic scar, AFX, PNST, poorly diff SCC

Regresssion

• § Dermal fibrosis (horizontally, unlike a dermal scar-vertical)
• § Inflammation
• § Usually associated with an epidermal component
• § Disappearance of malignant cells between nodules of malignant cells

Micro features of melanoma

• § Asymmetry
• § Poorly circumscribed
• § Lateral extension of epidermis beyond dermal nests
• § Pagetoid spread
• § Confluence of nests
• § Lack of maturation
• § Atypia, mitoses
• § Dermal lymphocytes

Breslow’s thickness

• § Top of granular layer OR ulcer base to deepest invasive tumor cells
• § If polypoid, still measure from granular cell layer

Clark’s levels

• § I: in situ
• § II: papillary dermis
• § III: filling papillary dermis
• § IV: reticular dermis
• § V: subcutaneous tissue

Growth phase:

Radial

• § ▪ tumour growing in radial manner with no invasion

Vertical

• § Tumour growing in vertical manner with:
• § 1 discrete, expansible nodule (usually at least a Clark III)
• § 2 nodule greater than largest nest in the epidermis
• § 3 mitotic activity
• § →tumour is thought to have metastatic potential
• § Satellitosis
• § 1 tumour should be a distinct nodule, at least 2mm away from the main tumour mass
• § 2 NO epidermal component
• § →thought to represent “in-transit” mets
• § -note: mets can have epidermal component w/ “epidermotrophism”

% of metastatic melanoma with HMB45- and MART1-?

• § 20%

Microinvasive melanoma

• § 1mm invasion

Radial growth

• § In situ or superficially invasive

Vertical growth

• § S

Prognosis

• § Depth
• § Ulceration
• § LN
• § Margin status
• § ▪ “sections show a punch biopsy of sun-damaged skin in which there is parakeratosis sparing adnexal structures which overlies partial thickness dysplasia.”
• § Risk factors:
• § ▪ UV exposure: sun,PUVA-treated psoriatic pts.,
• § ▪ immunosuppression: HIV,  organ tx,
• § ▪ chemical exposure
• § ▪ actinic keratosis
• § Clin: locally invasive with mets to only to nodes
• § Micro:
• § ▪ keratin pearls, intercellular bridges and rare keratohyaline granules
• § What are the variants of SCC?
• § spindle
• § verrucous
• § warty
• § basaloid
• § lymphoepithelial
• § papillary
• § acantholytic (sun-exposed skin)
• § non-keratinizing
• § keratinizing
• § ▪spindle SCC: lip, anaplastic spindle cells,
• § Ddx: AFX, melanoma, spindle cell lesions
• § ▪verrucous SCC: sole of the foot, ulcerated and fungating
• § ▪local invasion with deep sinus tracts
• § ▪assoc/ HPV
• § Micro: papillomatosis with hyperkeratosis and pushing invasion into dermis
• § Ddx: verruca vulgaris
• § Clinical: rapidly arising lesion, keratin-filled nodule
  Micro:
• § ▪ central crater filled with keratin & no granular  layer
• § ▪ irregular infiltrating squamous nests and islands
• § ▪ ↑inflammatory infiltrate with lichenoid features
• § ▪  neutrophils and eosinophils
• § regressing KA
• § ▪ keratin-filled crater
• § ▪↓inflm
• § ▪ well-developed granular layer

NON-MELANOCYTIC TUMOURS

Actinic keratosis

Squamous cell carcinoma

KERATOACANTHOMA

 

• § How to distinguish KA from SCC?
• § ▪ clinical: rapidly arising lesion (weeks)
• § ▪ overhanging edges
• § ▪ keratin-filled crater
• § ▪ hemispheric shape
• § ▪ eosinophils present (seldom seen in SCC),glassy cytoplasm
• § Clin:sun exposed, multiple tumors
• § older adults
• § Progression: Slow and indolent, locally invasive, rare mets
• § Risk factors:
• § fair skin, blue eyes, immunosuppression (higher incidence, more aggressive tumors), scars, basal cell nevus syndrome
• § Poor prognostic factors: dense fibrous stroma and loss of peripheral palisading, sclerosing (morphea-type)
• § Treatment: excision with frozen section evaluation of margins
• § Gross: nodular, ulcerative, superficial, erythematous or sclerosing (morphea-like)

basal cell carcinoma

• § Micro: epidermal attachment; nests or lobules of hyperchromatic but uniform basaloid cells with peripheral palisading, with retraction spaces
• § Variants: cystic, adenoid, keratotic, pigmented, infiltrating, sclerosing (morphea-like)
• § Positive stains: keratin, p53, bcl2
• § DD: AK, basaloid SCC, trichoepithelioma
• § Clin: nodular or ulcerated red-violet lesion
• § Micro:
• § ▪ small round cells with finely granular and dusty chromatin and multiple small nucleoli
• § ▪ little cytoplasm
• § ▪ diffuse or trabecular pattern
• § ▪ may be seen w/ SCC or eccrine tumours(in situ and invasive) → so thought is that it might arise from stem cell of ectodermal origin
• § IHC: dot-positive CK20, NSE+, chrA, syn
• § Negative IHC: CK7, TTF-1, CD45
• § Prog: aggressive with nodal and distant mets
• § Ddx: lymphoma, small cell from lung, other small round blue cell tumours, reactive

merkel cell carcinoma

 

• § HPV-associated lesions of the skin
• § Verruca vulgaris
• § Verruca planis
• § Condyloma accuminatum
• § Bowenoid papulosis (CIS of the penis)
• § Laryngeal carcinoma

 

• § Variants of BCC:
• § superficial
• § nodular
• § sclerosing
• § Apocrine glands:
• § ▪ hidradenoma papilliferum
• § Eccrine sweat glands:
• § ▪ clear cell acanthoma
• § ▪ cylindroma
• § ▪ eccrine spiradenoma
• § ▪ eccrine acrospiroma
• § ▪ syringoma
• § Hair follicles:
• § ▪ keratoacanthoma
• § ▪ pilomatrixoma
• § ▪ trichoepithelioma
• § ▪ trichofolliculoma
• § Sebaceous glands:
• § ▪ sebaceous adenoma
• § ▪ sebaceous carcinoma

ADNEXAL TUMOURS

Details…

• § Clear cell acanthoma
• § -acanthosis with clear cells
• § Eccrine spiradenoma
• § -painful, tender nodule
• § -low power: lobule or lobules “looks like a lymph node
• § -high power: two cell types 1) large pale nuclei
• § surround acinii-like structures + 2) small lymphocyte-like cells in b/w
• § Eccrine acrospiroma
• § -lobule with cells with clear cytoplasm and round dark nuclei + occ. tubule-cystic spaces
• § Pilomatrixoma
• § -ghost cells, calcification
• § Nodular hydradenoma
• § Trichoepithelioma
• § -keratin cysts + BCC-like basaloid nests
• § Trichofolliculoma
• § -main follicle with follicle-like nests budding off
• § Tricholemmal (pilar) cyst
• § Epithelial cyst with no granular cell layer
• § DF
• § DFSP
• § Small
• § larger
• § mid-upper dermis
• § deep dermis to SQ(fat infilt.)
• § foamy mf, hemosiderin-laden hf, Touton GC
• § no

MESENCHYMAL TUMOURS

fIBROUS/FIBROHISTIOCYTIC

§ collagen trapping with dense collagen § no § prominent vascularity (eg.sclerosing hemangioma) § no § No § storiform and monomorphic § No § increased mitoses § FXIII+ / CD34- § FXIII- / CD34+ § Clin: nodular, sun-exposed skin § Gross: nodular, often polypoid and ulcerated § Micro: nodular § ▪ spindle cell stroma § ▪ bizarre cells, freq mitoses, some atypical § IHC: CD68, h-CD § Prog: indolent, cured by excision § Note: some call AFX with necrosis in the subcutis, muscle, fascia→ MFH § Micro: homogeneous population of histiocytes abutting thined epidermis § ▪ Touton cells in upper dermis § Clin: sub-ungual, painful § Micro: round, uniform cells with abundant cytoplasm ® gives an epithelioid pattern § Micro: papillary fronds that resemble invasive angiosarcoma § Clin: assoc/ with AIDS, HHV-8 infection § Micro: § ▪ spindle cell proliferation w/ slit like endothelial spaces w/ extravasated RBCs § ▪ eosinophilic globules (PAS+) § IHC: Factor VIIIRA, CD31, 34, HHV-8 MoAb, FISH § Clin: bright elevated papule, lips, gingiva, skin § ▪ often seen w/ pregnancy § Micro: polypoid with attenuated epithelium § ▪ vascular prolif with edema § ▪ often central vascular capillary § Micro: hyperkeratosis, acanthosis, superificially dilated bv § ▪ collarette

ATYPICAL FIBROXANTHOMA

JUVENILE XANTHOGRANULOMA

XANTHELASMA

XANTHOMA

VASCULAR TUMOURS

GLOMUS TUMOUR

INTRAVASCULAR PAP. ENDOTHELIAL HP

KAPOSI SARCOMA

PYOGENIC GRANULOMA (LOBULAR CAPILLARY HEMANGIOMA)

ANGIOKERATOMA

 

LYMPHOID TUMOURS

CUTANEOUS LYMPHOID HYPERPLASIA

• § Micro: polymorphic lymphoid infiltrate with follicular centres
• § Micro:
• § ▪ variant of HP
• § ▪ associated with chronic discoid lupus
• § CD30 anaplastic T cells
• § Clin: >40yrs.
  3 stages:
• § pre-mycotic (red-brown patch)
• § Micro:-non-sp. psoriasiform dermatitis
• § Tx: UV light/steroids
• § 2. mycotic (plaque)
• § Micro:
• § ▪ atypical lymphocytes with cerebriform hyperchromatic nuclei in epidermis and dermis
• § ▪ Pautrier’s microabscesses (epidermal clusters of atypical lymphocytes) “Sezary cells”
• § Tx: UV light/steroids
• § tumourous stage
• § -may be associated with Sezary syndrome (hematogenous dissemination of lymphocytes with diffuse erythema and scaling (erythromderma))
• § Tx; chemotx.
• § IHC: CD3, CD4+ T lymphocytes
• § Name 3 types of bullous diseases and give examples of each.
• § Subcorneal
  • § -Pemphigus foliaceous
  • § -Staphylococcal scalded skin syndrome
  • § -Impetigo

JESSNER’S LYMPHOCYTIC INFILTRATE OF SKIN

LYMPHOMATOID PAPULOSIS AND ANAPLASTIC T CELL LYMPHOMA

MYCOSIS FUNGOIDES

LEUKEMIA

INFLAMMATORY LESIONS

BULLOUS LESIONS

 

• § 2. Suprabasal
  • § -Pemphigus vulgaris
  • § -Darier’s

 

• § Subepidermal
  • § -Bullous pemphigoid
  • § -Dermatitis herpetiformis
  • § -linear IgA dermatosis
  • § -epidermolysis bullosa

 

1. SUBCORNEAL

IMPETIGO

• § Cause: kids and adults: Staph aurueus → toxins A and B, which target desmoglein-1
• § ▪ Streptococcal variant associated with SSSS
• § Gross: crusted pustules
• § Micro: subcorneal bulla w/ nφ beneath stratum corneum→”subcorneal pustule” ; roof of pusture is parakeratotic stratum corneum
• § SS: Gram + for bacteria
• § -involves granulosa cell layer (see content for vulgaris) (desmoglein-1)

PEMPHIGUS FOLIACEOUS

 

2. SUPRABASAL

PEMPHIGUS VULGARIS

• § Cause: Ab’s directed at demosomes pr- (desmoglein-3)
• § Clin: oral and skin
• § Gross: bulla, blisters→rupture easily because not below epidermis
• § Micro:
• § ▪ acantholysis → cells become rounded
• § ▪ “tombstones” → (ie/”vulgar”)
• § IF: fishnet pattern→ IgG& C3 in lesional and non-lesional skin

DARIER’S

• § Clin: neck and trunk
• § Gross: symmetrical distribution of red-brown keratotic papules
• § Micro:
• § ▪ suprabasal clefts → dyskeratotic, basophilic cells with large nuclei and a paranuclear halo (grains or corps ronds (granular layer and stratum))
• § ▪ acanthosis and papillomatosis

 

3. SUBEPIDERMAL

BULLOUS PEMPHIGOID

• § Cause: autoimmune
• § Clin: elderly, flexor surfaces
• § Gross: tense bullae→ do not rupture easily since bulla is below epidermis
• § Micro:
• § ▪ no acantholysis
• § ▪ sub-epidermal blister with fibrin and eφ
• § ▪ PVLI w/ eφ + nφ
• § IF: linear at epidermal-dermal jnx→ IgG& C3 (bind to hemidesmosomes)
• § Cause: autoimmune
• § Clin: young adults, assoc/ celiac dz on extensor (“extends from skin to small bowel with celiac disease”)surfaces→ intensely pruritic
  • Ø anti-endomyseal, anti-gliadin, anti-transglutaminase Ab’s
• § -HLA DR3, B8à risk for lymphoma
• § Gross: uriticarial plaques and vesicles
• § Micro:
• § ▪ no acantholysis
• § ▪ sub-epidermal blister with fibrin and nφ,eφ at tips of papillae “microabscesses and vacuolization”
• § ▪ can spread along epidermal-dermal jnx
• § fibrin and eφ
• § IF: granular deposits at tips of derm papillae→ IgA
• § Tx: gluten-free diet
• § Clin: >12 genetic disorders
• § ▪ blisters form shortly after birth
• § ▪ hands, elbows, knees
• § Micro: subepidermal blister; superficial dermis is fibrotic
• § ▪ no inflammation
• § IF: linear deposits on epidermal-dermal bm →IgG&C3
• § EM: for classification
• § ▪ focal acantholysis
• § Causes:
• § CD @ L.A. HMV
• § Cryoglyounemia
• § Drug

DERMATITIS HERPETIFORMIS

EPIDERMOLYSIS BULLOSA

GROVER’S

LEUKOCYTOCLASTIC VASCULTITIS

 

• § Lupus
• § Arthritis
• § Henoch Scholein purpura
• § Meningococcemia
• § Viral hepatitis
• § Clin: children or adults with pruritic bullae throughout, assoc/ drug sens.
• § Gross: erythematous base
• § Micro: identical to dermatitis herpetiformis
• § IF: linear IgA at bm not dermal papillae

LINEAR IGA DISEASE

Name 4 types of transient acantholytic dyskeratosis

• § Spongiotic dermatitis
• § Hailey-Hailey
• § Darier’s
• § Pemphigus vulgaris
• § Causative agent: Bartonella henselae with AIDS
• § Clin: red papules and nodules
• § Micro: looks like a pyogenic granuloma
• § ▪ epithelioid endothelial cells and proliferative bv
• § ▪ extracellular purple-pink granular material → this stains with W-S!!!
• § ▪ nφ and fragmented nφ

BACILLARY ANGIOMATOSIS

 

PANNICULITIS

• § Classification:
• § Septal panniculitis
• § ▪erythema nodosum
• § ▪alpha-1-antitrypsin deficiency
• § Lobular panniculitis
• § ▪nodular vasculitis (erythema induratum)
• § ▪subcutaneous fat necrosis of newborn
• § ▪pancreatic fat necrosis
• § ▪lupus panniculitis
• § Findings in erytema nodosum and A-AT
• § Clin:shins (EN), legs and arms (AAT)
• § Micro:nφ,lφ,hφ with granulomatous infm and eventually fibrosis (detachm’nt of lobules w/ AAT)
• § Findings in nodular vasculitis
• § Clin:posterior calf (NV), assoc/ vasculitis of bv in subcutis, often sec. to TB
• § Micro: granulomatous infm of lobule and bv → may need multiple sections (NV)
• § ▪subcutaneous fat necrosis of newborn
• § ▪pancreatic fat necrosis
• § ▪lupus panniculitis

SEPTAL PANNICULITIS

LOBULAR PANNICULITIS

PALISADING GRANULOMAS IN THE SKIN

• § Prototypical example is granuloma annulare.
• § Clin: grouped annular papules on the dorsum(back) of the hand
• § Micro: palisading histiocytes and lymphocytes around loose collagen w/ cell debris
• § ▪ often will not see classic granuloma, just scattering of histiocytes and lymphocytes
• § Ddx:
• § ▪ necrobiosis lipodica (diabetic shins)
• § ▪ rheumatoid nodule (RA elbows)
• § ▪ O’Brien’s actinic granuloma (elderly faces)
• § Ddx of altered collagen:
• § -fibrous papule of the nose
• § -keloid/hypertrophic scar
• § -scleroderma/morphea
• § -granuloma annulare/necrobiosis lipoidica (collagen loose though)
• § What are the causes of necrotizing granulomatous vasculitis?
• § Wegener’s (usu also have lung lesions)
• § Churg strauss (more eφ + assoc/ asthma)

GRANULOMA ANNULARE

SPONGIOTIC DERMATITIS

Name types

Acute

• § Spongiosis + lymphocytic exocytosis
• § Superficial perivascular inflammation

Subacute

• § Add acanthosis, parakeratosis, and papillomatosis
• § Dilated capillaries, fibroplasias, and hemosiderin

Chronic

• § Remove spongiosis from the picture
• § Can be psoriasiform!
• § Stasis dermatitis, lichen simplex chronicus

“Dermatitis PPS”

• § Dermatitis (allergic, contact, atopic, seborrheic)
• § PP (pityriasis rosea, PURPP, Stasis)
• § Allergic→eφ
• § Contact→nφ
• § Pityrisasis rosea→herald patch then xmas tree
• § ▪ extravasated RBC’s and focal parakeratosis
• § PURPP→lφeφ
• § Stasis→dilated capillaries, fibroplasias, and hemosiderin
• § “DD, E, FF, G, L”
• § Vacuolization of basal keratinocytes with or without band of lφ

VACUOLAR INTERFACE DERMATITIS

Erythema Multiforme

• § Clin: mulitforme (macules,papulaes, vesicles, bullae) target lesion (red lesion with central clearing)
• § Steven-Johnson synd→assoc/ fevers, mm involvement
• § Micro:
• § ▪ vacuolar with spongiosis
• § ▪ single and clusters of necrotic kφ
• § Hemorrhagic sub-epidermal bullae→ toxic epidermal necrolysis
• § Note: -rolled section of separated epidermis shows full thickness necrosis unlike ddx which Staphylococcal scalded skin synd which shows subcorneal necrosis only.

Discoid Lupus Erythematosis

• § ▪ vacuolar
• § ▪ follicular plugging
• § ▪ hyperkeratosis or atrophy
• § ▪ thickened BM with granular IgG

Dermatomyositis

• § Clin: heliotrope rash with erythema→scaly eruptions→prox. muscle weakness

Fototoxic light reaction

Fixed drug reacφtion → eφ

Graft vs. host disease

Lichen sclerosis et atrophicus

• § ▪ see vulva
• § ▪ vacuolar
• § ▪ hyperkeratosis or atrophic
• § ▪ homogenized collagen
• § ▪ band of lymphocytes
• § ▪ in penis → BXO balanitis xerotica obliterans
• § “4 Ls’’
• § Lichen planus
• § ▪ dense band-like inflammation with saw toothed interface
• § ▪ squamotization of d-e jnx. w. basal layer disruption
• § ▪ colloid bodies
• § ▪ hyperkeratosis, coarse keratohyaline granules

LICHENOID DERMATITIS

Lichenoid drug eruption

• § ▪ + eos and parakeratosis

Lichenoid keratosis

• § ▪ solitary lesion

Lichen nitidus

• § ▪ collarette, tiny (1-2mm)

Mixed connective tissue disease

PSORIASIFORM DERMATITIS

Psoriasis vulgaris

• § ▪ Parakeratosis
• § ▪ No granular layer
• § ▪ Regular acanthosis
• § ▪ Thinned suprapapillary plates
• § ▪ Vascular papillae + perivascular inflammation
• § ▪ Munro’s microabscesses (nφ in epidermis)

Other causes of psoriasiform dermatitis

• § ▪ SCC
• § ▪ Mycosis fungoides
• § ▪ Lichen simplex chronicus
  ▪ Chronic spongiotic dermatitis
• § ▪ epidermal necrosis
• § ▪ wedge shaped inflm (superficial and deep) + extra. RBC
• § ▪ vacuolar change
• § ▪ massive acathosis
• § ▪ ulceration with fibrinoid material & granulation tissue
• § ▪ degenerated inflmd cartilage
• § ▪ early: perivascular and periadnexal inflm in deep dermis
• § ▪ later: sclerotic dermis (broad eosinophilic fibres) with lφ at interface b/w normal and abnormal collagen
• § ▪ mast cells (tightly packed in superficial dermis)
• § ▪ koilocytosis
• § ▪large eosionophilic inclusions in the granular layer (molluscum bodies)
• § ▪ glycogen acanthosis like
• § ▪ psoriasiform acanthosis
• § ▪ ectatic vessels
• § ▪ large stellate fibroblasts (esp. at d-e jnx)
• § ▪ fibrosis
• § ▪ basal cell hyperpigmentation
• § ▪ large nuclei and cytoplasm of squamous cells
• § Nodular: Discrete perivascular infiltrates that are so large they form nodules
• § Diffuse: Cellular infiltrate is so dense that discrete aggregates can no longer be recognized
• § Nodular – Histiocytes
• TB
• Sarcoidosis
• Granuloma Annulare
• Necrbiosis Lipoidica
• Rhematoid Nodules
• Ruptured Follicular Cyst (foreign body GC)
  • § Diffuse – Neutrophils
  • Granuloma Faciale (Grenz zone, mixed infm, focal leucocytoclastic vasculitis)
  • Sweet syndrome (mostly nφ, no vasc., acute fever)
  • Fungal, Mycobacterial Infections
    • § Diffuse – Histiocytes  (foamy histiocytes)
    • Xanthoma
    • Xanthogranulomatous inflm
    • Langerhans cell histiocytosis
    • Leprosy
      • § Diffuse – Plasma Cells
      • Syphilitic Chancre
      • Chancroid
      • Granuloma Inguinale, Lymphogranuloma venereum
      • Leishmaniasis
      • Plasmacytoma

MISCELLANEOUS

PLEVA (PITYRASIS LICHENOIDES ET VARIOLIFORMIS ACUTA

CHONDRODERMATITIS HELICUS NODULARIS

SCLERODERMA

URTICARIA PIGMENTOSA

CONDYLOMA ACCUMINATUM

MOLLUSCUM CONTAGIOSUM

CLEAR CELL ACANTHOMA

FIBROUS PAPULE OF THE FACE

LARGE CELL ACANTHOMA

PATTERNS

NODULAR AND DIFFUSE

NODULAR

DIFFUSE

• § Name 6 lesions assoc/ solar elastosis (ie/sun-damage)
• § AK
• § SCC
• § KA
• § Melanoma
• § Lentigo maligna
• § BCC

 

 

EYELID

• § ▪ keratinizing stratified squamous epithelium
• § Micro: multiple foci of granulomatous inflammation with microabscesses and multinucleated giant cells; center of granulomas may contain small fat globules
• § Micro: acute suppurative inflammation of sebaceous glands
• § Poxvirus
• § Micro: acanthosis +  molluscum bodies
• § -glds of Zeis or meibomian
• § Micro:
• § -marked atypia, mitoses
• § -can have comedo-like pattern
• § IHC: LMK

CHALAZION

STYE

MOLLUSCUM CONTAGIOSUM

SEBACEOUS ADENOCARCINOMA

 

• § Look out for:
• § BCC (cutaneous component only)
• § SCC
• § Merkel cell
• § adnexal tumors
• § melanocytic tumors
• § other skin tumours

CONJUNCTIVA

• § ▪ columnar epithelium (2-5 cells thick), goblet cells, melanocytes, S
• § bilateral degenerative process associated with sun damage and age
• § atrophic or thickened
• § Micro:
• § -actinic elastosis with variable hyalinization and calcification
• § -+/- foreign body cell reaction
• § bilateral, similar to pinguecula but extends onto nasal cornea
• § Micro:
• § -fibrovascular CT with corkscrew configuration of individual collagen fibers
• § -+/- acute/chronic inflammation
• § -+/- atrophy
• § Most important things first:
• § Breslow thickness
• § Clark’s level (I-V)
• § Mitotic rate (mitoses/mm²)
• § Ulceration
• § Regression
• § Tumor infilatrating lymphocytes
• § Radial growth phase
• § Vertical growth phase
• § Precursor lesion
• § Satellitosis
• § Multicentricity
• § Then the PS HHTTLL MNC
• § TX: cannot be assessed (e.g. shave biopsy regressed melanoma)
• § T0:
• § Tis: melanoma in situ
• § T1a: <1mm
• § T1b: <1mm & level IV or V OR ulcer
• § T2a: 1-2mm
• § T2b: 1-2mm + ulcer
• § T3a: 2-4mm
• § T3b: 2-4mm + ulcer
• § T4a: >4mm
• § T4b: >4mm + ulcer
• § ?melanoma →  excisional biopsy with narrow margins
• § ▪ if melanoma with BT <1cm deep
  • § →wide excision (1-2cm margins)
• § ▪ if melanoma with BT >1cm deep
  • § →wide excision + sentinal node biopsy
• § How do you handle a sentinel node biopsy?
• § ▪ section node every 3mm
• § ▪ cut 3 levels (1,3,5)
• § ▪ if negative, perform IHC for s100 and MelanA on intervening levels of interest
• § ▪ Ddx: nevus cells
• § Must use ocular reticule
• § From top of granular layer if non-ulcerated
• § From ulcer base overlying deepest point of invasion if ulcerated
• § Still from top of granular layer if polypoid (Gannon)
• § Intraepidermal melanocytes within adnexal epithelium should not be used as deepest invasion point
• § Avoid tangential cut
• § Satellitosis: intralymphatic metastasis within 2cm of primary
• § In-transit metastasis: intralymphatic metastasis between >2cm and first SLN
• § Regional nodal metastasis:
• § Microscopic metastasis: not detectable clinically or radiologically
• § Psoriasis
• § Impetigo
• § Fungal
• § Psoriasis: PMN, no granular cells
• § Psoriasiform keratosis
• § Lupus (vacuolar)
• § Lichen planus
• § Erythema multiforme (vacuolar)
• § Lichen sclerosis (vacuolar)
• § Drug eruption
• § Lichen nitidus
• § Lichenoid keratosis
• § Drug
• § Infections
• § Malignancies
• § Vasculitis
• § Herpes gestationlis linear BM C3
• § Panniculitis
  • Ø Septal: nodosum
  • Ø Lobular: factitial, pancreatitis, infections, lupus
• § Infectious vs non-infectious
• § FB
• § Crohn
• § Vasculitis
• § Neoplastic
• § Idiopathic: sarcoidosis,
• § GA: mucin, more superficial
• § NLD: layers, depper
• § RA: more palisading, fibrin
• § Necrobiotic xanthogranuloma: cholesterol, foamy cells
• § Polymorphous light reaction
• § Arthropod bite
• § Urticaria

PINGUECULA

PTERYGIUM

SYNOPTIC REPORT

STAGING

DECISION POINTS

SENTINEL NODE

BRESLOW THICKNESS (Lester)

DEFINTIONS FOR MELANOMA REPORTING

PMN IN EPIDERMIS***

PSORIASIFORM PATTERN***

LICHENOID***

ERYTHEMA MULTIFORME

LUPUS MICRO

BULLOUS LESION

GRANULOMAS

PERIVASCULAR INFLAMMATION

DARIER

GROVER

HAILEY-HAILEY

LEUKOCYTOCLASTIC VASCULITIS[7]

• § Fibrinoid necrosis
• § Extravasated RBC
• § Nuclear dusts
• § Infiltration by PMN
• § Microscopic polyarteritis
• § Churg-Strauss
• § Wegener
• § Granuloma faciale
• § Bechet

GRANULOMA FACIALE

• § Vasculitis
• § Grenz
• § PMN in epidermis
• § Panniculitis
• § Leukocytoclastic vasculitis
• § B27?

BECHET

DD dysplastic nevus and melanoma

• § Melanoma all atypical but dysplastic nevus have focal atypical and focal benign cells
• § Both asymmetric
• § Spitz nevus
• § Benign acral nevus
• § Recurrent benign nevus
• § Melanoma needs 1cm free margin regardless invasive or not
• § If invasive beyond 1mm, must do SLN
• § Stain for both S100 and MelanA
• § Melanin in macrophages
• § Clinical:
• § IHC:
• § Morphology: foamy cells, Touton, collagen trapping, storiform, depth, Grenz?
• § Blister=vesicle or bulla
• § Bulla: >0.5cm
• § Excoriation: linear traumatic breach of epidermis
• § Lichenification: thick roughened skin
• § Macule
• § Nodule: >0.5cm
• § Onycholysis: loss nail substance
• § Papule: ≤0.5cm, elevated
• § Plaque: >0.5cm, elevated
• § Pustule
• § Scale: dry, platelike, from aberrant keratinization
• § Vesicle: ≤0.5cm
• § Wheal: pruritic, erythematous, from dermal edema
• § Acantholysis:
• § Acanthosis
• § Dyskeratosis: abnormal keratinization below stratum corneum
• § Erosion
• § Exocytosis: inflammatory infiltration of epidermis
• § Hyperkeratosis
• § Lentiginous
• § Papillomatosis: elongation or widening of dermal papillae
• § Parakeratosis
• § Spongiosis
• § Ulceration
• § Vacuolization

BENIGN CONDITIONS WITH PAGETOID SPREAD

MANAGEMENT FOR MELANOMA

SLN PROTOCOLE

BLUE NEVUS

DERMATOFIBROMA VS FIBROSARCOMA

MACROSCOPIC TERMINOLOGY IN SKIN

MICROSCOPIC TERMINOLOGY IN SKIN