morph Flashcards
nests of nevus cells at the dermoepidermal junction
Junctional melanocytic nevus
nests or cords of melanocytes extend into the underlying dermis
Compound melanocytic nevus
complete loss of nests.
Intradermal melanocytic nevus
coalescent nests of nevus cells
dysplastic nevi
Lentiginous melanocyte hyperplasia
dysplastic nevi
Linear papillary dermal fibrosis d/t melanin incontinence
dysplastic nevi
hyperplasia of pigmented basaloid cells and hyperkeratosis; Keratin filled horn cysts
seborrheic keratosis
Basaloid cells with trichilemmal/hair-like differentiation.
Similar to germinal portion of normal hair bulb in anagen growth phase
Pilomatrixomas
o Tan-brown-red or flesh colored lesions < 1 cm. o Rough consistency. o Intercellular bridges o Elastosis: o Parakeratosis
actinic keratosis
o Firm, brown-tan papules. o Occasionally tender. o Lateral compression → inward dimpling o spindle shaped fibroblasts in a well-defined, mid-dermal non-encapsulated mass o Pseudoepithliomatous hyperplasia
Benign Fibrous Histiocytoma (dermatofibroma)
-Pseudoepithliomatous hyperplasia: Downward elongation of hyperpigmented rete ridges
o Firm nodules that are protuberant. o Storiform pattern o Overlying epidermis is thin o Honeycomb pattern o Infiltrates subcutis like "Swiss Cheese"
Dermatofibrosarcoma Protuberans
o Storiform pattern: Closely packed fibroblasts arranged radially (pinwheel appearance).
o Honeycomb pattern: Extension into SQ fat
Sezary-lutzner cells
Mycosis Fungoides (Cutaneous T-cell Loma (CTCL) =(hallmark): Malignant CD4+ Th cell with a hyperconvoluted (cerebriform) nuclei.
Pautrier microabscesses.
Mycosis Fungoides (Cutaneous T-cell Loma (CTCL) =band like dermal infiltrates with single cell invasion into the epidermis
spindle and stellate cells with toluidine blue or Giemsa stains to see granulessystemic mastocytosis
systemic mastocytosis
o edema and occasional dermal eos, but nfs are rare.
o Widely spaced collagen bundles.
o Dilation of superficial lymphatic channels
Urticaria (hives)
- Red, papulovesicular, oozing and crusted lesions.
- spongiosis
Acute Eczematous Dermatitis
CD8 in ctr, CD4 in periphery
Erythema Multiforme
Targetoid lesions:
Erythema Multiforme
=Red, maculopapular lesions with central pallor d/t necrosis of keratinocytes with associated perivenular inflamm (interface dermatitis).
~ test tubes in a rack
psoriasis
=Epidermal prolif : epidermal thickening (canthosis) w downward elongation of rete ridges
Auspitz sign:
psoriasis
=dilated vessels of underlying dermal papillae → pinpoint bleeds if overlying scale is removed.
spongiform pustules.
psoriasis
Munro microabscesses
psoriasis
Wickham striae: white dots or lines (hypergranulosis) on tha papules
lichen planus
Interface dermatitis:
lichen planus
=dense, bandlike, dermalepidermal junction lymphocytic infiltrate with basal cell degeneration and necrosis and jagged rete sawtoothing.