Cerebral cysticercosis.

A 44-year-old female underwent a right frontal craniotomy under a diagnosis of metastatic brain tumor and a fluid-filled cystic lesion was extirpated. One rice grain sized nodule was identified in the cyst and histopathological examination of the nodule showed a scolex with hooks and suckers. These macro and microscopic findings indicated a diagnosis of cerebral cysticercosis, caused by infection of the larval stage of some type of Taenia species. A therapeutic course of praziquantel was given after craniotomy. The patient has been a resident of the Kanto area of Japan since birth and has never been outside Japan.