Dural cavernous angiomas outside the middle cranial fossa: a report of two cases.

Cavernous angiomas of the dura mater are clinically and radiographically distinct from parenchymal cavernous angiomas. In this report, we present two cases of dural cavernous angiomas located outside the middle cranial fossa. The first patient is a 36-year-old woman with two dural cavernous angiomas, including one that enlarged during a 2-year period of observation. The second patient is a 33-year-old man with medically intractable seizures from a dural cavernous angioma of the convexity, which was discovered at autopsy. From our experience and a review of the literature, we have identified two groups of dural cavernous angiomas that differ in incidence, natural history, and surgical management. Most dural cavernous angiomas arise from the middle fossa; in contrast, only 15 cases of dural cavernous angiomas outside the middle fossa have been reported. Those in the middle fossa are more clinically aggressive and more difficult to resect surgically, because they grow toward the cavernous sinus and the parasellar region. Most patients with dural cavernous angiomas outside the middle fossa present with headaches, whereas those patients with dural cavernous angiomas in the middle fossa present with ocular signs, visual field defects, endocrinopathy, and trigeminal symptoms. Radiographically, both of the angiomas resemble meningiomas. Because of their intimate association with the cavernous sinus, surgical resection of middle fossa cavernous angiomas often is incomplete and may require postoperative radiosurgery to control growth. In contrast, angiomas in other locations are easily and successfully resected with little blood loss. The location of dural cavernous angiomas is an important factor in making the surgical decision and in predicting the outcome.