Numerous, small, darkly pigmented melanocytic nevi: the cheetah phenotype.
BACKGROUND
The presence of multiple atypical nevi or numerous melanocytic nevi increases the risk for the development of cutaneous melanoma.


OBJECTIVE
We sought to describe a distinct clinical phenotype characterized by numerous (>100), small (< or =4 mm), darkly pigmented melanocytic nevi that are uniform in color.


METHODS
Biopsy specimens from 6 patients (3 men and 3 women; age range, 44 to 81 years) with this clinical phenotype were reviewed and compared with a database of melanocytic lesions analyzed by the Yale Dermatopathology Laboratory (YDL) in the year 2000.


RESULTS
Of the 6 patients, 4 had multiple primary melanomas develop (n = 2-4), ranging from in situ to 1.0 mm in depth. The other 2 patients each had 1 nevus with severe cytologic atypia. When compared with the YDL database, our patients were more likely to have the following pigmented lesions: junctional melanocytic nevi, junctional lentiginous nevi, junctional nevi with cytologic atypia, and simple lentigines (P <.001).


CONCLUSIONS
The longitudinal evaluation of patients with this phenotype can be challenging because similar-appearing pigmented lesions (small and uniformly dark-brown to black) had a range of histologic diagnoses from simple lentigo to junctional lentiginous nevus to thin melanoma.
Department of Dermatology, Yale University School of Medicine, New Haven, Connecticut 06520, USA.
Phung M
PM
Huynh
Earl J
EJ
Glusac
Mayra
M
Alvarez-Franco
Marianne
M
Berwick
Jean L
JL
Bolognia
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D016208:Databases, Factual; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008545:Melanoma / Q000209:etiology / Q000473:pathology*; D008875:Middle Aged; D009508:Nevus, Pigmented / Q000145:classification / Q000150:complications / Q000473:pathology*; D010641:Phenotype; D010858:Pigmentation; D012307:Risk Factors; D012878:Skin Neoplasms / Q000145:classification / Q000209:etiology / Q000473:pathology*