[A Case of Male Hereditary Breast Cancer Involving a Sentinel Lymph Node Biopsy]

We report a rare case of male hereditary breast cancer in which a sentinel lymph node biopsy was performed. A 62-yearold man was admitted to our hospital because of a palpable tumor in his right breast. Both his younger sister and daughter had had breast cancer. Genetic testing revealed a morbid mutation in the BRCA2 gene. The tumor was palpated to an elastic hard mass and had a clear border in the right DCE area. We performed a core needle biopsy and diagnosed invasive ductal carcinoma, specifically, cT1cN0cM0, cStage I hereditary breast cancer. The patient underwent mastectomy and a sentinel lymph node biopsy. Nine days later, tamoxifen therapy was initiated. There has been no sign of recurrence during the 9 months after the operation.