[Trochlear neurinoma: case report].

A case of solitary neurinoma of the trochlear nerve was reported. The patient was a 37-year-old female, who had a sudden attack of right-sided temporal headache with nausea and vomiting on August 1, 1982. Headache was subsided in a few days but she had complained of diplopia since the episode. Ophthalmological examination revealed right superior oblique muscle palsy. She was neurologically free otherwise. CT scan, taken about three weeks after the onset, showed a solitary enhancing mass in the region of tentorial incisura on the right side. She was admitted to our clinic on August 24, 1982. Extensive work-up including polytomography, cerebral angiography, lumbar puncture, and so forth, revealed no abnormality. There were no cutaneous manifestations of von Recklinghausen's disease. Craniotomy was performed on October 28, 1982 and the tumor was totally removed by way of right subtemporal-transtentorial route. The tumor, size of which was 1.0 X 0.9 X 0.7 cm, was located just underneath the tentorial edge, and was adherent to it. The trochlear nerve was found incorporated in the tumor. Histological diagnosis was neurinoma of Antoni A type. Postoperatively, she was well and fully active, except for diplopia due to the sacrificed trochlear nerve.