Dermatopathology Flashcards
darkens with sun exposure
Ephelis/Freckles
Brown macular lesion that does not darken with sun exposure
Lentigo/lentigines
Melanin and melanocytes in freckles
Inc number of melanin in basal layer of epidermis
Normal melanocytes - number/morphology
Melanin and melanocytes in lentigo
hyperpigmentation in cells above BM
elongated rete ridges
melanocytes increased in basal layer
melanophages in upper dermis
How is melanocytic nevus different from melanomas
melanocytic nevus are
- uniformly pigmented
- well-defined, rounded
- melanocytes mature as they descend in dermis, and there is no deep mitoses (invading cells don’t mature)
where is melanocytic nevus well nested
dermal-epidermal junction
- restricted to tips/sides of rete
“Eosinophilic” collections of dyskeratotic melanocytes
Kamino bodies
Melanocytic nevi progression of maturation
junctional to compound to intradermal (dermal)
compound vs intradermal nevus
no nests in epiderdermis of intradermal nevus, but compound has nests in dermal-epidermal junction and dermis
key features of Spitz nevus
- Kamino bodies
- sharply defined laterally
- symmetrical
- clefts separate nests from keratinocytes
- Children
- deep red color (confused w/ hemangiomas)
Large, oval, multiple
Irregular pigment
Fading border - “fried egg appearance”
Histo: Compound/Concentric papillary dermal fibrosis
- bridging of adjacent rete
- hyperchromatic/enlarged nuclei
Dysplastic nevus
