Trigeminal Ganglioneuroma: A rare case of trigeminal neuralgia caused by Meckel’s cavum tumor: a case report and review of the literature

Background: Ganglioneuroma (GN) is a rare benign tumor originating from the sympathetic nerves, and its origination from the trigeminal nerves is even rarer. Only six cases of GN originating from the trigeminal nerve have previously been reported. Aim: To report a very rare case of GN arising in Mikel's cave revealed by atypical trigeminal neuralgia. Case report: A 24-Year-old Moroccan man presented left trigeminal neuralgia. Intracranial MRI showed a 4.4 x 2.5 x 3 cm well-circumscribed multilobular mass in the posterior middle fossa and the petroclival area with compression to the medial temporal lobe. The tumor appeared homogeneously hypointense on T1WI, and hyperintense on T2WI and T2WI-Flair, and showed heterogeneous moderate enhancement. Bone window petrous CT scan showed thinning and remodeling bone on the left petrous apex. The preoperative diagnosis was cystic schwannoma. The patient underwent a subtemporal extradural approach with total removal of the lesion. The histological and immunohistochemically study confirmed the diagnosis of GN. Postoperative was marked by left keratitis for two months. No recurrence was documented on 3 years follow-up. Conclusion: we described a benign and extremely rare trigeminal ganglioneuroma. This case is the seven-reported case in the literature. The subtemporal interdural approach must be considered in the surgical approach of trigeminal Meckel's GN. Trigeminal GN should be considered in the differential diagnosis of the tumor found in Mickel's cavum.