Solitary Osteochondroma of the Skull Base: A Case Report and Literature Review

We report a case of an osteochondroma in the posterior clinoid process that occurred in a 43-year-old man with trochlear nerve palsy. Although the potential preoperative diagnoses based on computed tomography and magnetic resonance imaging included other intracranial tumors such as calcified meningioma, thallium-201 single-photon emission computed tomography effectively differentiated osteochondroma from those possibilities. Via an orbitozygomatic approach, a subtotal resection was achieved with a good relief of symptoms. Twenty-two cases of solitary osteochondromas in the skull base have been reported that have demonstrated little risk of recurrence or malignant transformation. However, surgery for skull base osteochondromas does carry a significant risk with a reported mortality > 10%. Although some previous reports advocate complete resection as the only curative method for skull base osteochondromas, the risks of total resection should be weighed against the chance for recurrence; our review of the literature demonstrated a relatively high mortality and an extremely low incidence of recurrence.