[Neurinoma with intrasellar extension: a case report].

A 64-year-old female visited Kawatetsu Chiba Hospital complaining of left retro-orbital pain. A month before, she had experienced ptosis and diplopia, that had been releaved two days later by corticosteroid. On admission, she had no neurological deficits except for minimal anisocoria, with the left pupil larger than the right. There was no cutaneous manifestation of von Recklinghausen's disease. Skull X-ray films showed depression of the floor of the sella turcica on the left side. CT scans demonstrated a parasellar enhancing mass with intrasellar extension. Left carotid angiogram showed intracavernous portion of the internal carotid artery displaced laterally, inferiorly, and anteriorly. With a tentative diagnosis of laterally extending pituitary adenoma, a transsphenoidal operation was carried out, which disclosed a solid tumor locating beside the medially-displaced pituitary gland. The histological diagnosis was typical neurinoma. Parasellar neurinoma is not so common. It is usually difficult to determine the origin of the parasellar neurinoma. Trigeminal neurinoma arising from the Gasserian ganglion is generally recognized to be the most frequent. However, the absence of the trigeminal nerve involvement, unusual CT findings, and angiographical changes in the present case were all different from those of the typical trigeminal neurinoma. We believe that the tumor of this case originated from the oculomotor nerve. Fifteen cases of neurinoma of the oculomotor, trochlear, and abducens nerve have been reported to date. Their clinical features were reviewed.