Spontaneous acute hemorrhage within a subependymoma of the lateral ventricle: successful emergent surgical removal through a frontal transcortical approach

introduction. subependymomas are benign neoplasms intimately related to the ventricular system which only exceptionally associate hemorrhagic events. we present neuroradiological and pathological evidences of intratumoral hemorrhage within a single case of subependymoma operated on at our institution. additionally we analyze retrospectively the well-defined reports of similar cases published in the scientific literature. case report. a 71-year-old man on anticoagulant therapy presented with abrupt and progressive deterioration of his level of consciousness. emergent computed tomography and magnetic resonance imaging evidenced signs of acute bleeding within a mass located at the frontal horn of the left lateral ventricle, producing obstructive biventricular hydrocephalus. the lesion was immediately and completely removed through a left frontal transcortical approach. pathological diagnosis was consistent with subependymoma displaying areas of microhemorrhage. after surgery the patient developed global anterograde and retrograde amnesia. conclusions. a spontaneous hemorrhagic event within an asymptomatic lateral ventricle subependymoma can result in a surgical emergence as a consequence of sudden obstruction of cerebrospinal fluid pathways. prompt and radical surgical removal of the mass, which allows a rapid resolution of hydrocephalus and prevents the risk of rebleeding, may constitute the safest management strategy.