Management of pleural relapse after breast cancer resection in a middle-aged man: a case report.

Male breast cancer (MBC) is a rare breast carcinoma subtype with limited available data to fully delineate its recurrence patterns and guide evidence-based therapeutic strategies. We report a rare case of pleural relapse in a 59-year-old male patient following a radical resection of right breast cancer. Initially diagnosed with pathological stage IIIB disease, the patient then underwent adjuvant chemotherapy, radiotherapy, and endocrine therapy. During postoperative surveillance, persistent nodular pleural thickening along the interlobar fissures of the right lung was detected. Thereafter, the patient underwent pulmonary nodule resection and systematic lymph node dissection, with electrocautery-assisted resection or excision of all visible pleural nodules, followed by an immediate platinum-based intrapleural perfusion chemotherapy. Histopathological and immunophenotypic analyses confirmed metastatic breast carcinoma. Adjuvant therapy with abemaciclib and letrozole was initiated, and no recurrence was observed during the 27-month postoperative follow-up. Taken together, our findings underscore the importance of screening for solitary pleural metastasis at initial diagnosis and during follow-up for MBC and support a potential role for palliative surgical resection in locoregional MBC recurrence to achieve durable disease control and prolonged survival, providing a feasible treatment option for carefully selected patients.