Differential Diagnosis of Intracranial Neoplasms by Cerebral Angiography

In the diagnosis of intracranial tumor it is our aim to determine the site of the lesion and its histologic character. The first goal, so important for the surgical treatment, has been attained with a high degree of accuracy by the combined use of various diagnostic methods. The second postulate, viz., the preoperative recognition of the anatomic character of the lesion, is far more difficult to fulfill, yet it has considerable prognostic importance. Intracranial angiography not only has proved to be a reliable method for the localization of cerebral tumors, but frequently furnishes information as to the pathologic-anatomic type of the neoplasm by demonstrating a specific vascular pattern. In this respect the method is decidedly superior to ventriculography. Differences in vascularization of cerebral tumors have been known to neuropathologists and neurosurgeons for a long time and have recently been studied by advanced histologic methods (Hardman, 1). In certain neoplasms, differences of vascular design are of such gross nature that they can be demonstrated by angiography. Egas Moniz (2–5) and his pupils were the first to point out the angiographic features of angiomas, meningiomas, and certain vascular gliomas. They also recognized a conspicuous absence of vascularity in cysts, abscesses, and cholesteatomas. Tönnis (6) and Hemmingson (7) described certain changes characteristic for glioblastoma. With increasing angiographic experience, a number of workers have studied the specific arrangement of blood vessels encountered in various types of intracranial neoplasms (Almeida Lima, 8; Lorenz, 9; Egas Moniz, 10; Riechert, 11; Engeset, 12). In a series of 125 patients with intracranial tumor subjected to angiography at the University of Michigan Hospital, a special vascular pattern was observed in the following groups: angioma, meningioma, glioblastoma, certain types of astrocytoma. It must be emphasized here that a characteristic vascular pattern is not always to be found in such cases, but if it can be demonstrated it may be considered as almost pathognomonic. Angioma (8 Cases) Most of the lesions loosely designated as cerebral angiomas in reality are arteriovenous malformations. Although this group has been described in a previous communication (List-Hodges, 13), it will be discussed again to stress the features differentiating it from other intracranial lesions. In arteriovenous malformations (6 cases), one or several enlarged and unusually tortuous arteries lead to a tangle of smaller vessels forming a more or less well defined mass (Figs. 1 and 2). From this angiomatous malformation one or more greatly dilated and redundant veins emerge, carrying a mixture of arterial and venous blood (14, 15). The entire vascular malformation, including the venous connections, is shown during the arterial phase of angiography, since the contrast medium enters directly into venous channels through sizable arteriovenous connections within the angioma.