Emergency Embolization of Hemorrhagic Greater Superficial Petrosal Nerve (GSPN) Schwannoma: A Rare Case of Intracranial Hemorrhage.

Greater superficial petrosal nerve (GSPN) schwannomas are exceptionally rare and have not been previously reported to present with acute hemorrhage. In contrast, hemorrhagic vestibular and trochlear schwannomas have been described, often presenting with abrupt neurological symptoms. We report a case of a 41-year-old woman who presented with a sudden-onset headache and vomiting. CT revealed a hyperdense extra-dural lesion in the right middle cranial fossa, arising from an enlarged GSPN hiatus, with a subdural hematoma along the tentorium and fronto-parieto-temporal convexity (maximum thickness: 5 mm). MRI demonstrated a 25 × 20 mm extra-axial mass with heterogeneous T2 signal and perilesional edema. CT angiography showed intense enhancement, and digital subtraction angiography revealed a robust tumor blush with active contrast extravasation from the petrous branch of the middle meningeal artery. Super-selective embolization using 150-250 μm polyvinyl alcohol (PVA) particles achieved complete devascularization. Histopathological confirmation was not obtained, as the patient opted for conservative management; diagnosis was based on characteristic imaging features and precise anatomical localization. Post-embolization, the patient's symptoms resolved, and she was discharged neurologically intact by day 7. She remained stable at the three-month follow-up without symptom recurrence. This case represents the first reported instance of a hemorrhagic GSPN schwannoma. It underscores the importance of considering rare bleeding neural tumors in acute headache presentations and demonstrates that trans-arterial embolization can offer immediate hemostasis and clinical stabilization, providing a critical window for safe transition to planned surgical excision. This strategy may serve as a valuable adjunct in the management of similar cases of other hypervascular cranial nerve tumors presenting with acute hemorrhage.