Cavernous malformation of the optic chiasm: Neuro-endoscopic removal.

Cavernous malformations (CMs) arising from the optic nerve and chiasm are extremely rare. In large autopsy series, CMs were estimated to range from 0.02 to 0.13% in the general population. However, with introduction of MRI, these lesions were found more often than previously thought, ranging from 0.2% to 0.4%. Only 29 cases have been reported according to our knowledge. Most patients present with drop in visual acuity and visual field. Although MRI findings of cavernous malformations have been reported, they may not be diagnostic enough. Among the 29 reported, 16 underwent total resection with good results. In some, resection was complicated by damage to the surrounding neural tissue. Surgical removal is the recommended treatment to restore or preserve vision and to eliminate the risk of future hemorrhage. However, the anatomical location and eloquence of nearby neural structures can make these lesions difficult to access and remove. CMs appear to occur in every age group (range 4 months to 84 years mean-34.6 years) ith an approximately equal male to female ratio. They typically present with chiasmal apoplexy, characterized by sudden visual loss, acute headaches, retro orbital pain, and nausea.