[Primary Breast Cancer in a Man].

A 76-year-old man noticed a tumor under his right nipple. Mammography revealed an irregularly shaped nodule in the right breast. Ultrasonography showed a 20mm irregularly shaped nodule in the central area. MRI showed an 18mm irregularly shaped nodule in the central area with skin invasion. On core needle biopsy, the tumor was diagnosed as an invasive ductal carcinoma of the right breast. The patient underwent a mastectomy and axillary lymph node dissection. Histopathologically, the patient was diagnosed with invasive ductal carcinoma(scirrhous carcinoma). The tumor was positive for both ER and PgR, and the HER2 score was 1. The Ki-67 index was 20-30%. Male breast carcinoma accounts for approximately 1.0% of all breast carcinomas. The most common complaint is elastic, hard nodules with no pain. Postoperative therapy for male breast cancer is similar to that for female cancer. This patient underwent a mastectomy and lymph node dissection. After surgery, tamoxifen was administered as adjuvant therapy. There has been no evidence of recurrence for 4 months after the surgery.