blue nevi
Synopsis
common blue nevus
- vaguely nodular collection of poorly melanized spindled melanocytes
- deeply pigmented dendritic melanocytes within thickened collagen bundles
- scattered melanophages
- no mitoses
- well-demarcated nodule
- fascicles and nests of tightly packed
- moderately sized, spindled to oval melanocytes with scattered melanophages
- centered in the reticular dermis
- blunt-ended, bulbus extensions that extend into the subcutaneous fat
- occasional mitoses
- significant cytologic atypia
- areas of necrosis absent
epithelioid blue nevus (+/- with Carney complex)
atypical blue nevus
deep penetrating blue nevus
sclerosing blue nevus
amelanotic blue nevus
malignant blue nevus: malignant melanoma arising in association with a cellular blue nevus or growing in a histologic pattern similar to that of a cellular blue nevus
- pronounced cytologic atypia
- hyperchromasia
- necrosis
- increased mitotic rate
- infiltrative growth pattern
Types
classic blue nevus
cellular blue nevus
malignant blue nevus
Variants
epithelioid blue nevus
multiple blue nevi
plaque-type blue nevus (16205067)
Localization
skin
Rarely: vagina, spermatic cord, uterine cervix, lymph node, prostate, oral mucosa, bronchus
Epidemiology
most frequently noted in Asian populations (3-5% in adults)
1-2% of white adults
rarely found in blacks
uncommon at birth or in the first few years of life, with an estimated prevalence of less than 1 case per 1000 population.