[A Case of Familial Schwannomatosis Occurring as Intraorbital Schwannoma].

A 67-year-old male presenting with left exophthalmos and progressive visual disturbance was referred to our department. Tumors at the supraclavicular fossa and dorsal femoral region were resected at ages 27 and 45 years. His father and son had both been diagnosed with spinal tumors, and his son's tumor was pathologically diagnosed as a schwannoma. Brain MRI of his son demonstrated no intracranial tumor. Brain MRI of the patient revealed a multilobular tumor of 2 cm diameter compressing the optic nerve medially within the left muscle cone, and no other intracranial tumors. However, large masses lateral to the pharynx and intercostal nerve, as well as multiple spinal tumors were detected. Transcranial total resection of the intraorbital tumor was performed. The pathological diagnosis was consistent with a schwannoma. These clinical characteristics fulfilled the diagnostic criteria of familial schwannomatosis. The postoperative course was uneventful. His visual dysfunction and eye movement disorder resolved completely. The intraorbital tumor was believed to originate from the lacrimal nerve. Sequencing of all exons for SMARCB1 and LZTR1 using DNA extracted from the tumor did not reveal any mutations. This case is the third report on familial schwannomatosis in Japan.