Juxtaglomerular cell tumor - A clinicopathologic study of four cases and review of the literature

We studied 4 new cases of juxtaglomerular cell tumor and compared their mor phologic and immunohistochemical features with 2 renal hemangiopericytomas and 5 cutaneous glomus tumors. The juxtaglomerular tumors were resected fro m 2 males and 2 females (mean age at diagnosis, 23 years). Three patients m anifested with severe hypertension. Tumors ranged from 2.2 to 8.0 cin and w ere well circumscribed. The tumors consisted of solid sheets and nodules of variably sized tumor cells with round, oval, and spindled nuclei alternati ng with edematous microcystic foci. Nuclear atypia, present in all tumors, was a prominent feature in 2. Mitotic activity was not identified. All case s showed hemorrhage, numerous mast cells, and thick-walled blood vessels. U nusual features included coagulative tumor necrosis, a hemangiopericytoma-l ike vascular pattern, and hyalinized stroma. All tumors were immunoreactive for CD34 and actin. Ultrastructural analysis revealed the presence of rhom boid-shaped renin protogranules. Patients were treated by partial or radica l nephrectomy and followed up for 14 to 48 months. There were no recurrence s or metastases. The characteristic clinical and morphologic features of ju xtaglomerular cell tumor permit distinction from renal hemangiopericytoma a nd other renal tumors.