[A case of subependymoma in the lateral ventricle with intraventricular hemorrhage].

Subarachnoid hemorrhage attributable to brain tumor, particularly due to benign tumor, is not common. A case of subependymoma in the lateral ventricle, which manifested itself with an episode of subarachnoid hemorrhage was reported. A 33-year-old woman was admitted to our hospital because of severe headache and transient loss of consciousness, but neurological examination revealed no abnormality except for slight disturbance of consciousness and nuchal rigidity. Lumbar puncture showed an opening pressure over 350mmH2O and grossly bloody CSF. CT scan revealed an enhanced mass occupying the left ventricular trigone. Angiography, however, demonstrated no tumor stain or other vascular abnormality. Preoperative diagnosis was an intraventricular tumor of benign nature. A soft tumor arose from the lateral wall of the trigone was removed subtotally by paramedian parieto-occipital approach. Histology of the tumor was of typical subependymoma with scanty vascularity. Intraventricular or subarachnoid hemorrhage from cerebral neoplasm reported so far, is mostly due to a highly vascularized tumor. Subependymoma is of benign nature with poor vascularity, and therefore, intraventricular hemorrhage from the subependymoma was rarely reported in the literature. On the basis of the findings of angiography, serial CT scans and histological examination, it is reasonable to assume that intraventricular bleeding in our case is not attributed to the tumor per se, but to tearing of subependymal or ependymal veins extremely extended by the tumor growth.