A 62-year-old Japanese male patient presented with right oculomotor, abducens, and trigeminal nerve disturbances. Neuroimaging revealed a right middle cranial fossa mass lesion with the characteristics of trigeminal schwannoma. The patient underwent a right temporal craniotomy for gross total resection. Histological examination confirmed a metastasis of adenoid cystic carcinoma (ACC). After the operation, no evidence of the primary lesion could be found. The patient was treated with radiation therapy. ACC can be difficult to identify before histological confirmation. The incidence of intracranial invasion of ACC is 4-22%, but in this case no evidence of the primary lesion was found.
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