Colonization of nonmelanocytic cutaneous lesions by dendritic melanocytic cells: a simulant of acral-lentiginous (palmar-plantar-subungual-mucosal) melanoma.

Four cases of colonization of nonmelanocytic lesions by dendritic melanocytic cells are reported, one in a verruca vulgaris of the lip, one in a squamous cell carcinoma in situ of mucous membrane overlying a tonsil, one in a lesion of lichen simplex chronicus with a nevocellular nevus of the external ear, and one in a dermatofibrosarcoma protuberans (Bednar tumor). This is an important biological process of melanocytes that must not be confused with the acral-lentiginous (palmar-plantar-subungual-mucosal (P-S-M) melanoma. It is probably much more common than the paucity of published reports would indicate.