Teaching Neuroimages: Basal Ganglia Germinoma with Hemiatrophy

Excerpt

A 15-year-old Caucasian boy presented with an over-months slowly progressive hemiparesis, first of his right arm and eventually of his right leg (grade 4/5). He suffered from speech deterioration with worsening of articulation and fluency, declining school performance, and repetitive nocturnal enuresis. He was considered to have long-standing right-sided facial palsy due to an ischemic event in early infancy, although no imaging study was performed at that time. Magnetic resonance imaging showed a multicystic lesion associated with atrophy of the left basal ganglia (Fig. 1a). The white matter of the anterior frontal lobe and the left basal ganglia showed a fluid-attenuated inversion recovery hyperintense signal, a high signal in diffusion-weighted images at a b-value of 1000 (Fig. 1b), and—more remarkably—tiny, partly enhancing cysts along the genu of the corpus callosum and the right caudate head (Fig. 1c). Unenhanced computed tomography (CT) showed these structures to be hyperdense (Fig. 1d). Stereotactic biopsy of the contrast-enhancing lesion at the tip of the left frontal horn revealed a germinoma.

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