Surgical findings in idiopathic trigeminal neuropathy mimicking a trigeminal neurinoma

Idiopathic trigeminal neuropathy is a benign disorder where the main clinic al feature is facial numbness limited to the territory of one or more divis ions of the trigeminal nerve, persisting for a few weeks to several years a nd in which no underlying disease can be identified. The case of a 37-year- old man with a brief history of sensory and motor trigeminal symptoms who s howed magnetic resonance imaging (MRI) findings consistent with a small tri geminal neurinoma is reported. The patient was operated on but no tumour co uld be found during surgery and a biopsy was taken from the portio major. P athological diagnosis was chronic non granulomatous inflammatory reaction w ith areas of coagulation necrosis. Control MRI showed complete resolution o f the trigeminal abnormalities. It is concluded that in patients with MRI f indings suggestive of a small trigeminal schwannoma, benign idiopathic trig eminal neuropathy should also be considered in the differential diagnosis. A conservative approach with sequential MRI studies may avoid an unnecessar y surgical exploration.