Sudden visual loss and a chiasmal syndrome due to an intrachiasmatic vascular malformation.

A 48-year-old woman presented with a chief complaint of visual loss and bitemporal hemianopia. A similar episode of temporal visual field loss had occurred 34 months earlier and spontaneously resolved. Computerized tomography demonstrated a suprasellar mass. Angiography was normal. At surgery a venous angioma of the optic chiasm with a fresh hematoma was found and removed. Intrachiasmatic vascular malformation is an unusual finding which should be considered in the differential diagnosis in patients with a chiasmal syndrome.