[The tentorial meningioma fed by "marginal tentorial artery" arising from the external carotid artery--a case report and review of literature (author's transl)].

It is well known that a Bernasconi-Cassinari artery is an important finding at diagnosis of the abnormality in tentorium. Since Bernasconi and Cassinari reported the artery in 1956, many reports have been presented and showed that the artery arose from the intracavernous portion of the internal carotid artery. We presented a 54-year-old female with tentorial meningioma. In selective external carotid angiography, the artery feeding the tumor was revealed arising from the accessory meningeal artery, which came off the internal maxillary artery and passed into the carnium through the foramen ovale, and took the same course of "Bernasconi-Cassinari artery". This angiographic finding suggests that it is possible for marginal tentorial artery to arise from an external carotid arterial system. It is said in the anatomical studies, when the trunk of primitive maxillary artery which is one of maxillo-carotid anastomotic arteries in fetus regresses, "marginal tentorial artery" usually remains linked to the internal carotid artery. But, if this transition of "the artery" from the external to the internal carotid artery failed, it is easily conceived the artery results in the origin of accessory meningeal artery, a branch of the external carotid artery.