Isolated Maxillary Extracranial Metastasis of a Suprasellar Germinoma

Intracranial germinomas are exquisitely radiosensitive, and a tissue diagnosis obtained by minimal biopsy followed by radiotherapy (with or without chemotherapy) provides excellent long-term control; aggressive resection adds morbidity without oncological benefit. We report a 20-year-old man whose sellar and suprasellar mass was preoperatively interpreted as a pituitary adenoma and was treated by aggressive endoscopic endonasal transsphenoidal resection after an intraoperative frozen section suggested adenoma; final histology demonstrated germinoma. The postoperative course was complicated by a persistent skull-base cerebrospinal fluid (CSF) leak, methicillin-resistant Staphylococcus aureus meningitis/ventriculitis, and CSF dissemination documented by repeatedly positive CSF cytology and elevated CSF β-human chorionic gonadotropin. The initial skull-base reconstruction failed, and the resulting persistent CSF rhinorrhea required revision dural repair on postoperative day (POD) 29; proton craniospinal irradiation was delivered from POD 52. The patient achieved remission but, approximately 21 months after completing radiotherapy, developed a destructive germinoma lesion in the midline maxilla, with no recurrence at the primary site and no leptomeningeal disease at that time. In light of the anterior maxillary location and the relatively long interval after radiotherapy, we interpret the lesion as an isolated extracranial metastasis rather than a proven operative-tract event. The principal lesson is that accurate initial diagnosis and approach selection-measurement of tumor markers and minimal or transventricular biopsy in preference to resection-remain essential in young patients with sellar/suprasellar masses in whom germinoma is a diagnostic possibility.