Germinoma of the basal ganglia. An 8-year asymptomatic history after detection of abnormality on CT.

We describe a case of germinoma of the left basal ganglia. An 11-year-old boy, who demonstrated calcification of the left basal ganglia on CT scan following a head injury at the age of 3 years, presented with a weakness of the right upper extremity for 2 months. MRI demonstrated high intensity in the left basal ganglia on a T1-weighted image without enhancement as well as high intensity on a T2-weighted image. Ipsilateral hemiatrophy of the hemisphere and midbrain was also noted. In addition, high intensity in the left internal capsule and cerebral peduncle was demonstrated on T2-weighted image. Surgical specimens obtained by stereotactic biopsy showed germinoma with a two-cell pattern. The patient had remained asymptomatic for 8 years after abnormal calcification was initially detected on CT scan. Ipsilateral hemiatrophy of the hemisphere and midbrain was demonstrated before the onset of weakness.