[A case of intraventricular isolated neurosarcoidosis diagnosed by neuroendoscopic biopsy]

A 76-year-old woman was admitted to our hospital because of dementia, nausea, and speech disturbances. Computed tomography(CT)of her brain showed hydrocephalus and an intra-ventricular mass with a left temporo-parieto-occipital low density area. She underwent emergency ventricular drainage. Thereafter, she was referred to our department: neurosurgery. Gadolinium-enhanced magnetic resonance imaging of the brain showed homonymous enhancement in the left lateral, third, and fourth ventricles. CT of her chest and abdomen showed no abnormal findings. Initially, we performed a neuro-endoscopic biopsy and made a histopathological diagnosis of noncaseating granuloma. However, because we did not detect pulmonary or ocular lesions, we eventually made a diagnosis of isolated neurosarcoidosis. She received a ventricular-peritoneal shunt and steroid pulse therapy, and recovered from all her symptoms. Neurosurgeons should be aware of the possibility of hydrocephalus mimicking an intraventricular tumor and caused by isolated neurosarcoidosis. In this article, we provide a case description and review of the literature.