A locally infiltrative juxtaglomerular cell tumor with unusual histologic features.

Juxtaglomerular cell tumor (JGCT) is an exceptionally rare renal tumor with a predominantly benign clinical course and classically bland histology. It commonly presents in young adults and manifests as hypertension related to renin secretion. We report a JGCT initially thought to be a renal cell carcinoma. It was unique because of its size, high-grade histologic features and locally infiltrative nature-extension into the renal pelvis. It is unclear whether features such as tumor necrosis, pleomorphism and increased proliferative activity are predictive of metastatic potential and/or locally aggressive behavior. Clinical follow-up may be warranted in such cases.