Korean J Dermatol.  2006 Jan;44(1):109-112.

A Case of Atypical Melanocytic Hyperplasia

• Lee KH
• Cho YK
• Han YW
• Jun YJ
• Park CJ

Abstract

In atypical melanocytic hyperplasia, histopathologically atypical melanocytes are not distributed throughout the epidermis, but are present in some parts of the basal layer of the epidermis without dermal invasion, despite the lesion being present for a long time. Differential diagnosis of melanoma in situ (MIS) from atypical melanocytic hyperplasia is difficult. Furthermore, the concept of atypical melanocytic hyperplasia remains controversial, and the criteria for clinical and histologic diagnosis of atypical melanocytic hyperplasia have not yet been fully determined. Many further studies are needed to define the clinical and histologic characteristics of atypical melanocytic hyperplasia. A 48-year-old man presented with asymptomatic, solitary, 2 x 1.5 cm sized, poorly-defined, irregular, brownish to black patch on the volar area of the left index finger for 5 years. The histopathologic findings revealed an increased number of large atypical melanocytes in the basal layer, consistent with atypical melanocytic hyperplasia. Therefore, we report a case of atypical melanocytic hyperplasia.

Keyword

Atypical melanocytic hyperplasia

MeSH Terms

Diagnosis
Diagnosis, Differential
Epidermis
Fingers
Humans
Hyperplasia*
Melanocytes
Melanoma
Middle Aged