[Primary pigmented breast adenocarcinoma in a male patient]

Pigmented mammary tumours are rare. Herein, we report the third case of primary pigmented breast adenocarcinoma in a male patient with clinical mimicking of nodular melanoma of the nipple.

A male patient presented with a pigmented nodule of the right nipple. Histological examination of the lesion showed dermal and subcutaneous adenocarcinomatous proliferation. The perilesional stroma contained melanin both inside and outside macrophages, leading us to conclude on primary pigmented breast adenocarcinoma clinically mimicking nodular melanoma of the nipple.

Local production of melanin by neoplastic cells in the mammary carcinoma was postulated as the cause of hyperpigmentation of the tumour. Other possible causes are transfer of melanin from overlying melanocytes of the pigmented areolar epidermis to the underlying neoplastic cells, or melanin synthesis by intratumoral melanocytes migrating from the epidermis (which strikes us as the most convincing interpretation for the reported case).

Breast adenocarcinoma is a rare tumour in men and may present clinically as a pigmented lesion of the nipple, resulting in the problem of differential diagnosis with primary or metastasised nodular melanoma.