Primary Renal Well-Differentiated Neuroendocrine Tumor (Carcinoid) in a Horseshoe Kidney

Abstract

A female patient was found to have a horseshoe kidney on imaging studies when undergoing evaluation for recurrent urinary tract infections when she was in her 20s. Now in her late 40s, she presented with gross hematuria. A computed tomography urogram revealed the presence of a 14.9-cm mass arising from the isthmus of the horseshoe kidney (Figure 1). Also present was an enlarged retroperitoneal lymph node suspicious for metastatic disease.