Two adjacent nodules on the leg.

Poroma is a rare benign neoplasm (derived from the intraepidermal part of the eccrine or apocrine duct), which may clinically mimic malignant tumors such as (amelanotic) malignant melanoma and porocarcinoma. Histopathological examination is the key to the correct diagnosis, which is illustrated in the present case, in which a pigmented basal cell carcinoma and a poroma are in close proximity to each other. Despite a clinical differential diagnosis of melanoma, histopathology showed the typical characteristics of a poroma, a rare but much more favorable tumor. Histopathological features of poroma are discussed.