Early Diagnosis of Male Breast Cancer: A Case Report and Literature Review.

Male breast cancer (MBC) is a rare neoplasm, and this rarity underscores the critical importance of awareness and appropriate screening. This study presents a case of male breast cancer (MBC) in a 64-year-old patient to enhance understanding of this rare and frequently underdiagnosed neoplasm. A 64-year-old man presented with a palpable mass in the left breast. Imaging revealed bilateral gynecomastia and a highly suspicious 4.3-cm Breast Imaging Reporting and Data System (BI-RADS) 5 nodule with nipple retraction. Biopsy confirmed histologic grade III invasive ductal carcinoma. Immunohistochemistry showed positivity for hormone receptors (Estrogen Receptor (ER) 90%, Progesterone Receptor (PR) 50%) and was negative for Human Epidermal Growth Factor Receptor 2 (HER2). Following left mastectomy, the patient experienced postoperative complications, including a contralateral hematoma and a persistent seroma. Oncotype diagnosis (DX) testing indicated a low chemotherapy benefit, leading to adjuvant therapy with tamoxifen. Pathologic tumor stage pT1c and pathologic nodal status pN0, confirmed by sentinel lymph node biopsy, indicated early-stage disease. The complexity of MBC underscores the critical importance of early diagnosis. The prompt detection of the suspicious mass, culminating in effective early-stage treatment, proved crucial to this patient's favorable prognosis, in contrast to the common trend of delayed diagnoses and their less promising outcomes. Accordingly, strengthening public awareness and professional training is essential to optimize management and improve outcomes in men with breast cancer.