Primary human chorionic gonadotropin secreting germinoma of the corpus callosum.

Background: Primary intracranial germinomas are a rare subset of intracranial tumors derived from mis-incorporated germ cells within the folding neural plate during embryogenesis. Though known to arise from midline structures in the central nervous system (CNS), occurrence within the corpus callosum is exceedingly rare.

Case Description: We present a rare case of secreting primary intracranial germinoma with extensive intraventricular metastasis presenting as a multi-cystic butterfly lesion in the genu of the corpus callosum in a young boy.

Conclusion: Intracranial germ cell tumors must be considered for any multi-cystic lesion arising from midline structures in the CNS in the preadult population.