Jugular foramen schwannomas

Abstract

Thirteen patients with schwannomas of the jugular foramen were operated on at the Cleveland Clinic between 1974 and 1983. The authors' experience in managing these rare tumors is presented. Three major growth patterns of jugular foramen schwannoma were seen, and it is postulated that the position of the tumor depends on its point of origin from the nerves as they pass through the pars nervosa of the jugular foramen. The more distal lesions will expand inferiorly out of the base of the skull, and the more proximal lesions will enlarge into the posterior fossa. Tumors in the mid region will tend to expand primarily into bone. The schwannoma was primarily intracranial in six patients. In five patients the tumor expanded the bone at the base of the skull, with only a small intracranial component, and in two patients the tumor was primarily extracranial, with a small extension into the bone or posterior fossa. The presentation of the patients varied according to the tumor growth pattern. Deafness, vertigo, and ataxia were present in all patients with a major intracranial component, and in most of these there were only minimal deficits of the jugular foramen nerves. By contrast, lower cranial nerve involvement, including hoarseness and weakness of the trapezius and sternocleidomastoid muscles, occurred in patients in whom the tumor was primarily, within the bone or extracranial. Three of the five patients with the major component of the schwannoma within the bone also had deafness. Symptomatic history was longest in those with tumor mainly involving the bone at the base of the skull, and shortest in patients with entirely extracranial tumor. Surgical resection was accomplished with a joint neurosurgical-otological approach, usually combining a posterior fossa exploration with either a translabyrinthine transcochlear or infralabyrinthine procedure. The exact nature of the operation depended upon the presence of intracranial tumor and on the extent of bone or extracranial involvement. Total excision was performed in all cases. There was no operative mortality, and surgery resulted in loss of function of the ninth, 10th, and 11th cranial nerves in most patients. The major postoperative morbidity consisted of swallowing difficulties and sputum aspiration.