PERIPHERAL-NERVE HEMANGIOBLASTOMA

Capillary hemangioblastoma (HB) is a benign, highly vascular tumor lim ited almost exclusively to the central nervous system (CNS). It occurs primarily in the posterior fossa and less often in the spinal cord. W e report three cases of HE occurring in peripheral nerve, two intradur al tumors arising in a C4 and a cauda equina nerve root, respectively, and a third lesion in the sciatic nerve at mid thigh. The patients, 1 woman and 2 men, ranged in age from 25 to 49 years, Two had von Hippe l-Lindau disease, an association usually found in one-third of CNS HBs , and one had a family history of pheochromocytoma. In every way, HBs of peripheral nerve were indistinguishable from their CNS counterpart. Ranging in size from 1.5 to 5.5 cm in diameter, the tumors were well circumscribed and contained a myriad of small caliber vessels lined by endothelial cells and surrounded by pericytes. Throughout, the lesion s were rich in large, often vacuolated stromal cells. In all of the ca ses, these stained strongly for vimentin and neuron-specific enolase; only one showed focal S100 protein reactivity. Surgical therapy requir ed excision of the affected nerve roots in the first two cases. In the third case, prominent extension of the tumor within epineurium permit ted a microsurgical resection with sparing of sciatic nerve fascicles. No tumor recurred during a follow-up period of 5 to 20 months.