Clinically distinct form of acquired dermal melanocytosis with review of published work.

Dermal melanocytosis is most commonly found in the skin of Asians and other darkly pigmented people. It is histologically characterized by the presence of dermal melanocytes, with or without presence of dermal melanophages. Mongolian spot, nevus of Ito, nevus of Ota, nevus of Hori, and blue nevus are most common and represent distinct types of dermal melanocytosis. Other clinical patterns of acquired dermal melanocytosis have also been described. Herein, we report a unique case of acquired dermal melanocytosis diffusely affecting the entire back of a 50-year old African-American male and also review and discuss various patterns of unusual acquired dermal melanocytosis.