Early diagnosis of basal ganglionic germinoma by MRI

The magnetic resonance (MR) imaging findings of a germinoma originating from the left basal ganglia in a 22-year-old Chinese man are presented. The patient was initially diagnosed with schizophrenia due to the psychiatric presentations of mental deterioration and behavior changes. MR images showed a cystic tumor in the left globus pallidus which was homogeneously hypointense on T1-weighted images and hyperintense on both T2-weighted and fluid attenuated inversion recovery (FLAIR) images. The cyst showed good water diffusion characteristics on echoplanar diffusion-weighted images. On enhanced T1-weighted images, the tumor showed a very thin enhancing rim. Moreover, ipsilateral cerebral and cerebellar atrophy was present although the tumor was small. The atrophy seemed to progress even when the tumor regressed after radiotherapy. Early diagnosis of basal ganglionic germinoma by MRI is possible and may lead to a better prognosis.