Jugular Foramen Schwannomas: Surgical Approaches and Outcome of Treatment

Abstract

Twelve cases of schwannomas of the jugular foramen that involved surgery in our department between 1983 and 1997 are described. Eight were women and 4 were men (mean age, 40 years), and the duration of their symptoms, the most predominant of which were hearing loss and tinnitus, ranged from 1 month to 20 years (median, 8.5 months). Depending on their radiological and surgical features, tumors were classified as type A, a tumor primarily at the cerebellopontine angle with minimal enlargement of the jugular foramen (n = 5); type B, a tumor primarily at the jugular foramen with or without intracranial extension (n = 4); type C, a primarily extracranial tumor with extension into the jugular foramen (n = 0); or type D, a dumbbell tumor with both intracranial and extracranial components (n = 3). A retrosigmoid suboccipital craniectomy (RSSOC) was performed for type A tumors; for types B and D, the RSSOC or staged infratemporal fossa approach (ITFA)/RSSOC was used. Total removal was achieved in 6 cases, near total removal in 3, and subtotal removal in 3. The most common complication was lower cranial nerve dysfunction (n = 5). The follow-up period ranged from 6 to 173 (mean, 48) months, and there was no recurrence. Two patients showed regrowth of the tumor after subtotal resection, however. In 1 of these, the residual tumor had progressed within 12 months of initial surgery, it was again resected and linac radiosurgery was successful. In the other, the residual mass had progressed within 8 months of initial surgery, and the pathological report indicated malignant peripheral nerve sheath tumor. Conclusively, type A tumors could be totally resected with the retrosigmoid approach alone. For type B and D tumors, however, combined ITFA and retrosigmoid approach showed the better results. In spite of our limited data, cases showing adhesion to critical structures can be managed by subtotal or near total resection followed by radiosurgery to reduce postoperative complications.