Solitary renal metastasis from salivary epithelial–myoepithelial carcinoma mimicking renal cell carcinoma: A case report of robot-assisted partial nephrectomy

Renal metastasis from salivary epithelial-myoepithelial carcinoma (EMC) is exceptionally uncommon. A 74-year-old woman with parotid EMC had previously undergone two pulmonary metastasectomies. A 27-mm mass was detected in the upper pole of the left kidney 14 years after initial parotidectomy. Contrast-enhanced computed tomography demonstrated mild enhancement without washout, indicating non-clear cell renal cell carcinoma or metastatic disease. Robot-assisted partial nephrectomy was performed, and histopathology confirmed metastatic EMC with biphasic atypical tubules composed of CK7-positive luminal epithelial components and p63-positive myoepithelial components. This case highlights diagnostic challenges and the need to consider late metastasis after prolonged disease-free intervals.