Juxtaglomerular cell tumor of the kidney

The authors describe a juxtaglomerular cell tumor (JGCT) which caused severe hypertension in a 58-year-old man. Light microscopy showed a circumscribed tumor composed of interlacing cords and occasional nodules of relatively uniform cells with no mitotic activity. Rhomboid crystals characteristic of "prerenin" were present within the cytoplasm of tumor cells, and there was a close relationship between the tumor and unmyelinated nerve axons. Intracytoplasmic renin was demonstrated by immunofluorescence, and tumor granules were shown to contain zinc by electron-beam microanalysis. Review of 14 prior cases, with additional follow-up of 9, showed that no patient had developed recurrence, metastasis, or another tumor. Four patients, however, are hypertensive but probably because of secondary tumor effects rather than recurrent hyperreninism. The distinction of JGCT from hemangiopericytoma with renal involvement is important because of the high mortality associated with the latter. The authors conclude that JGCT is benign, but patients with JGCT may remain hypertensive postnephrectomy because of hypertensive angiopathy.