Schwannomas of the jugular foramen.

Schwannoma is an important entity in the differential diagnosis of the enlarged jugular foramen. Our recent experience with 4 consecutive large schwannomas over a 12-month period is presented. As these tumors are usually less vascular than glomus jugulare tumors, they are frequently more amenable to surgical extirpation. Radiologic clues to their identity include discrete borders and less angiographic vascularity when compared with glomus jugulare tumors. Our operative treatment of these cases has evolved to include preoperative embolization with Ivalon sponge particles, followed by a lateral temporal bone resection in exposing the jugular foramen. A posterior fossa craniotomy is done as a second stage when necessary. This staging allows for less morbidity and greater chance for total tumor removal. The surgical technique and relevant anatomy are reviewed and illustrated.