[Malignant Melanoma of a Male Breast That Was Difficult to Differentiate from Breast Cancer-A Case Report].

Introduction: Malignant melanoma in the male breast is extremely rare. Here we report a case of malignant melanoma in which a small cystic lesion in the male breast gradually increased during follow-up and was difficult to distinguish from breast cancer.

Case: A 65-year-old male was diagnosed with a tumor in the right breast and was referred to our department for further examination.