SUMMARY Cerebral venous sinus thrombosis (CVST) is

Renal oncocytoma is a benign tumor which arises from collecting duct cells. It may be detected incidentally or present with hematuria and flank pain. It is a rare occurrence in pregnancy. Here, we present a case report of a 26-year-old patient who was detected with a renal mass in pregnancy and radical nephrectomy was performed 5 months after delivery. Gross examination of the kidney showed a well-circumscribed tan brown tumor. Microscopy revealed neoplastic oncocytes arranged in nests, alveolar, and tubular pattern having round central nuclei with evenly dispersed chromatin and abundant eosinophilic granular cytoplasm. On immunohistochemistry, these cells were positive for CD117 and negative for CK7, CD10, S100, and Hale's colloidal iron stain. Diagnosis of oncocytoma was given.