Prostatic melanosis is a rare lesion that is characterized by melanin-containing spindle cells mainly located in the stroma of the prostate gland. This lesion is certainly benign and not a precursor of malignant melanoma. However, differential diagnosis of melanosis with primary and metastatic malignant melanoma is extremely important because of the different biological nature and clinical behavior of these two entities. Recognition of the spectrum of pigmented lesions in the prostate gland is essential to take into consideration of the diagnosis of melanocytic lesions.

In this paper, a case of melanosis of the prostate in a 65- years old man is described and differential diagnosis of the melanocytic lesions is discussed.