Cavernous Malformations of the Skull Base and Cranial Nerves

• Published in: Skull Base Vol. 17; no. S 2
• Main Authors: Bitner, John B, Olsen, Kerry D, Giannini, Caterina, Driscoll, Collin L.W, Link, Michael J
• Format: Conference Proceeding Journal Article
• Language: English
• Published: 13.06.2007
• ISSN: 1531-5010; 1532-0065
• DOI: 10.1055/s-2007-981752

Introduction: Cavernous malformations (CMs) typically are intraparenchymal CNS vascular lesions with very characteristic MRI appearance. Rarely, they have been reported to involve extraparenchymal sites such as the dura, dural venous sinuses, and calvarium. We present four cases of CMs involving the skull base and cranial nerves mimicking more common benign skull base tumors. Methods: In the past year we have operated on four patients with lesions felt to represent either schwannoma or meningioma that subsequently were found to be CMs involving the skull base and cranial nerves. We reviewed the pre- and postoperative imaging and neurologic exam, operative findings, and pathology. Results: The lesion locations included the internal auditory canal and vestibulocochlear nerve, cribiform plate and olfactory nerve, Meckel's cave and trigeminal nerve, and cavernous sinus and abducens nerve. All patients were male (mean age, 47.5 yrs; range, 42 to 57 yrs). Presenting symptoms included hearing loss, tinnitus, imbalance, headache, facial numbness and pain, and diplopia. Three CMs were removed completely with no increase in preoperative neurologic deficit. The CM within the cavernous sinus was subtotally resected to avoid permanent ophthalmoplegia. Final pathology in all cases revealed CM. Conclusion: CMs of the skull base and cranial nerves are very rare lesions and can mimic much more common pathologies such as meningioma and schwannoma. They are extremely vascular, and a high suspicion preoperatively and immediate awareness intraoperatively when a CM is encountered are very important. En bloc resection can result in radiographic cure with low risk of morbidity for lesions outside the cavernous sinus.