Cavernous Hemangioma of the Trochlear Nerve in Asian Population: Case Report and Review of the Literature.

Trochlear nerve cavernous hemangioma (CH) is a rare disease. There have been only five such cases reported in the world literature till date. The authors report a case of trochlear nerve CH in the Asian population and review the relevant literature. A 49-year-old Asian woman presented with gradually worsening double vision for 6 years. Physical examination identified a complete paralysis of left trochlear nerve. In imaging, a circular lesion measuring about 1 cm in diameter was found in the left ambient cistern. The lesion was completely excised through the left-side subtemporal approach, with a diagnosis of trochlear nerve CH confirmed by pathological examination. Further nerve anastomosis was not adopted, and the patient remained clinically stable in a two years' follow-up. This report provides more information about the history characteristics, imaging features, and surgical treatment strategies for trochlear nerve CH.