Urothelial Carcinoma of the Renal Pelvis Mimicking Acute Pyelonephritis with Abscess

Abstract

Primary tumors of the renal pelvis and collecting system are relatively uncommon. Their clinical presentation is nonspecific and variable, and they can be mistaken for a variety of conditions, including acute pyelonephritis or renal abscesses. A 75-year-old man have had abdominal pain for one week. He was diagnosed for acute pyelonephritis based on the radiologic findings initially. Repeated abdominal computed tomography was done after 3 months later, because of the relapsed abdominal pain. Abdominal computed tomography revealed lobulated abscess in the left kidney with enlarged central necrotic para-aortic lymph nodes. Laparoscopic excisional biopsy was performed at necrotizing lymph node and the histologic evaluation revealed an urothelial carcinoma. This report presents an unusual case of urothelial carcinoma that initially mimicked acute pyelonephritis but presented as a renal abscess several months later.