[Mixed breast carcinoma with melanocytic differentiation in a man]

Introduction: Male breast cancer is rare; the lobular type is exceptional. Only one case of mixed ductal and lobular type is reported in the literature. This is the first report on a mixed ductal and lobular carcinoma with melanocytic differentiation in a man. The aim of our study is to describe the clinicopathological characteristics of this rare type of breast tumor and to discuss its histogenesis.

Case report: A 63-year-old man presented with cutaneous ulceration of the left breast. Ultrasound of the breast revealed a solid hypoechoic lesion, 13 mm in diameter. Microscopic evaluation of the biopsy showed an invasive ductal carcinoma. The patient received three cycles of chemotherapy and lost of view. Then consulted for increasing of the tumor size reaching 3 cm. Histological examination of the mastectomy specimen showed a mixed ductal and lobular carcinoma with melanocytic differentiation, confirmed by the immunohistochemical study. The patient received adjuvant chemotherapy and the evolution was favorable with an average follow-up of 9 months.

Conclusion: Breast carcinoma with melanocytic differentiation is extremely rare; only seven cases are reported in the literature and all occurs in females. Its histogenesis is unclear; tumors exhibiting this combination of cell types may occur as collision or composite tumors.