Isolated metastasis of renal clear-cell carcinoma to the male breast following nephrectomy: A rare case report.

introduction and importanceRenal cell carcinoma (RCC) accounts for approximately 2 % of adult malignancies, with clear-cell RCC being the most common histological subtype. Metastasis to the breast is extremely rare, particularly in male patients, and may mimic benign breast lesions, creating diagnostic challenges. PRESENTATION OF CASE: We report the case of a 55-year-old male with a history of left nephrectomy for clear-cell RCC (pT3aN0M0) who presented three years later with a painless nodule in the left breast. Imaging revealed a well-circumscribed hypoechoic mass classified as BI-RADS 3. Wide local excision was performed, and histopathology with immunohistochemistry confirmed breast metastasis from renal clear-cell carcinoma. No adjuvant systemic therapy was administered, and the patient remains disease-free on follow-up. CLINICAL DISCUSSION: Breast metastases from extramammary malignancies are uncommon and typically occur in women. In men, they are exceptionally rare and often mistaken for benign conditions such as gynecomastia. Histopathological and immunohistochemical analyses are crucial to distinguish metastasis from primary breast carcinoma. For selected patients with oligometastatic or oligo-recurrent disease, complete metastasectomy may offer prolonged disease control and defer systemic therapy.

conclusionThis case highlights the importance of considering breast metastasis in male patients with a history of extramammary malignancy. Accurate histopathological diagnosis is essential, and in selected cases, surgical excision can be an appropriate management strategy.