Clear cell papillary renal cell carcinoma: A case report and review of the literature

Clear cell papillary renal cell carcinoma(ccpRCC) was recently established as a distinct type of epithelial neoplasm by the International Society of Urological Pathology Vancouver Classification of Renal Neoplasia. Here,we report a case of partial nephrectomy for a ccpRCC detected during the routine follow-up of a previously treated liposarcoma in a 70-year-old male patient. The patient was referred to the urology department for a right-sided renal mass(size: 2 cm)detected during routine annual imaging follow-up for a malignant right inguinal fibrous histocytoma and liposarcoma that had been diagnosed 6 and 4 years earlier,respectively,and treated with surgery and adjuvant radiation therapy.Following partial nephrectomy,the renal mass was pathologically diagnosed as ccpRCC,and immunohistochemistry revealed carbonic anhydrase 9(CA9)expression. No recurrences or metastases were detected on follow-up imaging for6 months. This is the first report of partial nephrectomy for incidentally discovered CA9-positive ccpRCC.