Advanced dual primary male breast cancer and lung cancer: A case report and literature review.

The current report presents a unique case of advanced male invasive breast cancer coexisting with synchronous primary lung adenocarcinoma, a rare clinical manifestation. The case contributes to the limited literature on male breast cancer and its association with multiple primary malignancies. The patient, a 59-year-old man, presented with a large ulcerative mass in the left breast (14×10 cm) and ground-glass opacities with calcified nodules in the right lower lung lobe (14×14 mm). Imaging and pathology confirmed stage IIIB invasive ductal carcinoma of the breast [human epidermal growth factor receptor-2-positive, estrogen receptor-positive (80%) and progesterone receptor-positive (5%)] and minimally invasive lung adenocarcinoma. Treatment consisted of neoadjuvant chemotherapy (epirubicin + carboplatin + trastuzumab + pertuzumab), a modified radical mastectomy with latissimus dorsi flap reconstruction and a thoracoscopic lung wedge resection. The therapeutic approach resulted in partial remission of the breast cancer prior to surgery and a stable disease status in the lung, with no recurrence at the 1-year follow-up. This case underscores the importance of comprehensive, integrative strategies and long-term follow-up for managing rare, complex cancer cases.