A case of juxtaglomerular cell tumor with novel histologic features.

Juxtaglomerular cell tumors constitute a very small group among the renal neoplasms. Most secrete renin, causing hypertension and hypokalemia due to secondary hyperaldosteronism. They have characteristic pathological features. For the accurate evaluation, diagnosis has to be confirmed by immunohistochemical staining for renin or electron microscopic demonstration of renin protogranules. This report presents a case of renal juxtaglomerular cell tumor in a 63-year-old man with previously unreported histological findings in addition to classic morphology.