Germinoma arising in the basal ganglia in early stage: CT and MR findings.

We report a patient with a germinoma originating in the left basal ganglia. Unenhanced computed tomography (CT) revealed a relatively well-defined high-density lesion, which was slightly enhanced with contrast medium. No tumor stain was noted on angiography. The mass showed hypointensity on T1-weighted magnetic resonance imaging (MRI), and heterogeneous hyperintensity on T2-weighted imaging. The lesion was homogeneously enhanced after the administration of Gd-DTPA. To our knowledge, the MR findings of basal ganglia germinoma have been retrospectively reviewed in just four reported cases, only two of which were examined with Gd-DTPA enhancement. The two cases revealed relatively large masses with cysts and peritumoral edema, and were slightly enhanced after the intravenous injection of Gd-DTPA. Our case was thought to be in the early stage, and its CT and MR findings were slightly different from those of previously reported cases.