Bifocal germinoma of the septum pellucidum and the sellar-supra-sellar region: An uncommon presentation for a rare tumor

Intracranial germinomas (IGs) are rare malignant germ cell tumors. The septum pellucidum (SP) is an extremely rare site of IGs. To our knowledge we report the first patient presenting with synchronous involvement of the SP and the sellar region. A 28-year-old woman presented with unsteady gait, mild left motor deficit, polydipsia and polyuria of 2-month duration. Imaging revealed a multicystic butterfly lesion in the SP extending to the frontal lobes, with unusual CT and MRI features, associated with a sellar area lesion. A navigation-guided biopsy revealed a pure germinoma. MRI at 12 months after the completion of the radiation therapy showed the resolution of the lesions. She achieved complete remission at 8-year follow-up. IG arising in the SP is rare but should be considered in the differential diagnosis, especially in young adult and particularly in male, presenting with multi-cystic lesion. The presence of a synchronous mass is a clue for the presumptive diagnosis of germinoma. These findings suggest that IG in SP may present as a large tumor with large cysts and may look as central neurocytoma. ADC value is helpful to differentiate them.