Dermatopathology - Entities & Features Flashcards
Clear cell acanthoma
Clear demarcation from epidermis
Often neutrophils present
PAS + showing abundant glycogen
Poroma
Small monomorphic cells Epidermis ‘raining down’ Sharp demarcation of epidermis to dermis Glandular structures in dermis Connected to basal layer of epidermis Forms vertically oriented columns Ductal spaces
Trichilemmoma
Acanthosis in epidermis
Eyeliner sign / peripheral palisade
Some koilocytic like changes at edges of lesion
Clear cell change due to glycosylation of cytoplasm
Overlying hypergranulosis and hyperkeratosis
Fibroepithelioma of pinkus
Fenestrated strands off epidermis
BCC like areas in scaffold
PHLDA1 marker - less staining in basaloid areas , more staining in pink areas
Tumour of follicular infundibulum
Epidermal epithelial growth with a plate like configuration and multiple connections to the epidermis
- keratinocytes have glycogenated appearance resembling those of outer root sheath
Prominent surrounding basement membrane
Elastosis perforans serpinosa
- extrusion of elastin fibres / transepidermal elimination
- associated folliculitis
- can have overlying parakeratosis with neuts
Folliculitis de calvans
Plasma cells Polytrichia Scarring fibrosis Neutrophilic abscesses Hair shaft granulomas Lymphocytes
Granular cell tumour
Overlying epidermis may show pseudoepitheliomatous hyperplasia
Proliferation of large to polygonal cells with granular eosinphilic cytoplasm in sheets
Individual cells with indistinct borders, small round centrally located nuclei
Large eosinophilic
S100 +ve
CD68 +ve
Syringocystadenoma papilliferum
CYSTIC neoplasm opening into surface
Epidermis has hyperplasia and papillomatosis
Tumour shows papillary growth pattern with papillae composed of FIBROVASCULAR CORE surrounded by 2 layers of cells — inner tall columnar cells with eosinophilic cytoplasm
Plasma cells conspicuous
Look for associated sebaceous naevus
DDx: hydrocystadenoma, hydradenoma, hidradenoma papilliferum,
Granuloma annulare
Closed off palisading granulomas Upper third epidermis Granulomatous inflammation Mucin stain positive (colloidal iron, alcian blue) Normal dermis visible Eosinophils Multinucleated giant cells
Acantholytic acanthoma
Papillomatosis, epidermal hyperplasia with overlying hyperkeratosis
Prominent acantholysis throughout epidermis
Mild superficial perivascular infiltrate
Acute generalised exanthematous pustulosis
Subcorneal or superficial intraepidermal neutrophilic pustules with admixed few acantholytic keratinocytes
Background spongiosis with neutrophilic exocytosis and scattered dyskeratotic cells
Papillary dermal oedema
Perivascular mixed inflammatory infiltrate
Dermatofibroma aka fibrous histiocytoma
- Epidermal hyperplasia with flattened rete ridges ,
- Basal induction - induction follicles and sebaceous glands
- Poorly circumscribed proliferation of spindled and/or epithelioid fibroblasts and histiocytes
- Multinucleated giant cells - touton like
- Xanthomatised histiocytes
- Cellular dermis with collagen entrapment more prominent at periphery
Pilomatricoma
- Multinodular tumour in dermis and/or subcutis composed of nests resembling those of the hair matrix with abrupt transition to central shadow cells
- calcifications and foreign body granulomatous response
- numerous mitotic figures
Sebaceous adenoma
Nodular sebaceous and basaloid proliferation
Broadly connected to epidermis
Predominance sebaceous glands
Minimal cytological atypia
Erosion overlying is commmon
More mature sebocytes over less differentiated blue cells
Lipidized cells
MMR gene mutations MSH2, MSH6, PMS2, MLH1
T/F viral cytopathic change going down hair follicles is more likely VZV than HSV
True
Palisaded encapsulated neuroma
Well circumscribed but non encapsulated
Usually cleft but no capsule
Spindled cells wavy nuclei
Mast cells present
Bullous arthropod bite reaction
Subepidermal bulla ,
eos predominate
Superficial and deep eosinophilic infiltrate
Cylindroma
Jig saw arrangements of basaloid islands
Two cell populations small basaloid cells periphery and larger pale cells centrally
Eosinophilic aggregates within nests and around nests forming stroma
What is a sunburn cell
Single or few apoptotic cells high up in epidermis
Consistent with a photodermatosis
Polymorphous light eruption
Variable epidermal spongiosis with dyskeratosis
Superficial and deep mixed inflammation (mostly lymphocytic)
Red cell extravasation
Marked papillary dermal oedema
Chronic cutaneous lupus erythematosus
Follicular plugging
BM thickening
Lichenoid reaction pattern - basal vacuolation and apoptotic keratinocytes
Superficial and deep lymphocytic infiltrate
Mucin interstitially
Lupus tumidus
Relative sparing of epidermis
Superficial and deep lymphocytic inflammation
Mucin deposition interstitially
Subacute cutaneous lupus erythematosus
CF. DLE - presence of more epidermal atrophy - epidermal atrophy Basement membrane thickening Mucin deposition Superficial and deep lymphocytic infiltrate with periappendegeal spread /peri-eccrine - Less hyperkeratosis - Less Basement membrane thickening - Less follicular plugging - Less inflammatory infiltration