Migratory neurocysticercosis mimicking a third ventricular colloid cyst. Case report.

The authors report on a case of solitary neurocysticercosis located in the anterior third ventricle of a 21-year-old Hispanic man who presented with progressive headache, nausea, and mental decline. The appearance of the lesion on computerized tomography and magnetic resonance studies was typical of that of a colloid cyst. which was the presumptive preoperative diagnosis. A transcortical-transventricular microsurgical approach was used, and inspection of the anterior third ventricle via the ipsilateral foramen of Monro revealed no lesion. Inspection of the floor of the ipsilateral lateral ventricle revealed the intact cyst, which had migrated since the preoperative studies had been obtained. The lesion was removed intact, and histopathological examination confirmed the diagnosis of neurocysticercosis. The authors review the radiographic findings in this case and further illustrate the potential for neurocysticercosis to masquerade as other intracranial lesions.