Histological verification of microaneurysms as a cause of cerebral haemorrhage in surgical specimens.

Surgical specimens taken from 14 patients with lobar intracerebral haemorrhage or cerebellar haemorrhage without vascular abnormalities on angiograms were examined histologically. In seven of the 14 patients, arteriovenous malformation or amyloid angiopathy were found by ordinary pathological examinations. Among the remaining seven patients, definite microaneurysms were verified in five and possible ones in two patients by using the technique of serial sectioning of the solid nodular tissues removed from the presumed bleeding site, where an arterial connection between the tissues and the surrounding brain was noted. Four of these seven patients had no history of hypertension and showed normal blood pressure before and after surgery. To verify microaneurysms in surgical specimens, it seems important to search the presumed bleeding site properly by a meticulous microsurgical technique and to section the tissues serially for the histological examination.