A Rare Case of Enhancing Anterior Interhemispheric Racemose Neurocysticercosis with Foci of Calcification and Direct Parenchymal Extension

Neurocysticercosis (NCC) refers to the central nervous system (CNS) infestation of the larvae of pork tapeworm Taenia solium. It is endemic in Central and South America, Asia and Africa. It most commonly presents as intraparenchymal subcentimetric ring enhancing lesions of variable ages (or size and duration) with surrounding vasogenic edema. The lesions calcify with time. Rarely, NCC can occur in extraparenchymal locations, within the subarachnoid space and ventricles. At these locations it is usually seen as a proliferative lobulated cystic mass without a scolex which is termed racemose neurocysticercosis. Racemose cysticerci do not show calcification, scolex, or enhancement.

We report a case of a 23-year-old man with a two-year history of headache. CT and MRI showed multilocular bubbly cystic mass with epicenter in the anterior interhemispheric fissure showing intraparenchymal extension into adjacent bilateral parasagittal frontal lobes. There was a central nodular calcification and mild peri-lesional vasogenic edema. Rim enhancement was observed in the cysts on post contrast study. The diagnosis of racemose cysticercosis was made on biopsy. Despite being racemose, our case showed coarse central calcification and rim enhancement of the cystic portions, which are rare entities and hence reported here. Direct intraparenchymal extension of racemose form of NCC has not been reported in the literature to date, and our case is the first of this kind to be reported.