Surgical removal of a live worm by stereotactic targeting in cerebral sparganosis. Case report.

A 64-year-old man presented with generalized tonic clonic convulsion followed by weakness of the right lower extremity. He had a medical history of hypertension, hyperlipidemia, and right cerebellar infarction. Computed tomography (CT) showed a small high density nodule with an enhanced perifocal low density area in the left occipital lobe. T1-weighted magnetic resonance (MR) imaging showed a ring-shaped and partial string-like nodule with enhancement by gadolinium. T2-weighted MR imaging showed the white matter of the left occipital lobe as high intensity. CT and MR imaging seemed to indicate metastatic brain tumors, although cortical atrophy and ventricular dilation were recognized. Left parietal craniotomy was performed under stereotactic targeting to obtain a definitive diagnosis. During manipulation at the center of the targeted lesion, a white, tape-like body was found and recognized to be a live worm. Serological testing revealed strong immunopositivity against Spirometra mansoni. The infection route in the present case was probably through eating raw chicken meat. Cerebral sparganosis is extremely rare but should be considered in the differential diagnosis of metastatic brain tumors, especially in endemic areas.