Infiltrating Ductal Breast Carcinoma in a Male Patient With Associated BARD1 Mutation.

Male breast cancer is an uncommon diagnosis with limited research on management and prognosis due to its rarity. We discuss a case of a 55-year-old male with a non-contributory past medical history who presented with an enlarging palpable mass of his right breast tissue at the 10:00 position. The ultrasound of the right breast showed a 2.8 cm heterogenous mass with irregular borders highly suspicious for malignancy. The follow-up sonogram-guided core biopsy was performed, and the pathology of the mass confirmed high-grade infiltrating ductal carcinoma. A modified radical mastectomy of the right breast with extensive axillary lymph node excision was performed. Genetic testing of the excised tumor revealed a MUTYH gene mutation and a BARD1 (BRCA1-associated RING domain 1) gene mutation of unknown significance. Histopathological analysis confirmed a Grade 2, ER/PR-positive, KI 67-positive, and HER2-negative tumor.