Cavernous malformations of the third ventricle.

CAVERNOUS MALFORMATIONS ARE uncommon lesions that are usually present in the cerebral hemispheres. Less frequently, these malformations are seen in the brain stem, basal ganglia, or paraventricular regions. We report four cases of cavernous malformations of the third ventricle. Patients presented with symptoms of hydrocephalus, memory loss, and signs of hypothalamic dysfunction. Magnetic resonance imaging and computed tomography provided characteristic images of the three lesions preoperatively. All patients underwent direct surgical excision of the malformations. Two patients had a transcallosal, transventricular approach, the third underwent a transcortical, transventricular approach, and the fourth had an infratentorial supracerebellar approach. Postoperatively, the patient with hypothalamic dysfunction has not improved and underwent ventriculoperitoneal shunting. The second patient did well initially; however, 8 days postoperatively, she became comatose and later died. The presumed cause of her deterioration was a hypothalamic venous infarction. The third and fourth patients have returned to their normal neurological baseline. The presenting signs and symptoms, magnetic resonance imaging and computed tomography findings, and treatment options for this rare lesion are discussed and illustrated.