Primary small cell carcinoma of kidney after renal transplantation：a case report and literature review

Extrapulmonary small cell carcinoma （EPSCC） is a rare neoplasm comprising 2.5％ to 5％ of small cell carcinomas （SCCs）.Bladder SCC is the most common site of genitourinary tract.Primary renal SCC is extremely rare.We report a case of primary SCC of the kidney which is rarely reported in the urinary tract and presents an aggressive clinical picture.A 59-year-old female visited a urologic clinic with complaint of persistent left flank soreness 10 years after undergoing renal transplantation.Abdominal computed tomography showed a left renal pelvis tumor.After the patient received left nephroureterectomy with bladder cuff resection,her pathology results showed SCC.After surgery,she received adjuvant systemic chemotherapy,and her recovery has been uneventful as of 8 months.Primary renal SCC presents with an advanced tumor stage and a short median survival period,therefore early intervention and close follow-up are recommended.