Capsuloganglionic Germinoma: A Rare Site for Uncommon Childhood Tumor

Germ cell tumors (GCTs) are rare intracranial tumors with a strong predilection for children. Commonly, these tumors arise either in the suprasellar or the pineal region. The basal ganglia-thalamus complex represents a rare site of nonmidline intracranial GCTs. Such basal ganglionic GCTs have been reported to produce certain interesting clinico-radiological features, the knowledge of which may provide important diagnostic clues preoperatively. We present the case of a 9.5-year-old boy who presented with right hemiparesis and precocious puberty. Imaging revealed a heterogeneously enhancing mass involving the left capsuloganglionic region, sparing the thalamus. There was little perilesional edema and midline shift. Because of the deep location of the mass and a lack of mass effect, a neuronavigation-guided tumor biopsy was performed which unraveled a pure germinoma. The child was referred for adjuvant radiotherapy following an uneventful postoperative course. At the time of writing the report, the child was on radiotherapy and doing well.