Histopathological Features of Brain Arteriovenous Malformations in Japanese Patients

Clinical features of high risk brain arteriovenous malformations (BAVMs) are well characterized. However, pathological evidences about the differences that are possessed by high risk patients are still lacking. We reviewed archived routine hematoxylin-eosin specimens from a total of 54 surgical treated BAVMs. The histopathological features in nidus were semi-quantitatively analyzed. We obtained the pathological differences of BAVMs nidus between several clinical features. Among the analyzed pathological features, the significant differences were observed in degree of venous enlargement and intimal hyperplasia. Juvenile, female, diffuse nidus, high Spetzler-Martin grade, and low flow patients had a lesser degree of those parameters compared to adult, male, compact nidus, low Spetzler-Martin grade and high flow patients. High risk profiles of BAVMs patients were well-reflected in the nidus pathology. Therefore, juvenile, female, diffuse nidus, and low flow in Japanese BAVMs patients might have different vascular remodeling process that predispose to higher tendency of hemorrhage.