Vertebral angiography of cerebellar astrocytoma

Thirteen cases of cerebellar astrocytoma were examined primarily for tumor stain and pathological tumor circulation by angiography and CT. Tumor stain was observed in only one case by cerebral angiogram. A tumor was demonstrated as an avascular mass in the remaining 12 cases. It is suggested that mural nodules of cystic lesions should have certain weight and sizes so that they could be demonstrated as tumor stain. In the supratentorial region, five of the 12 low-grade astrocytoma exhibited abnormal tumor stain and tumor circulation by cerebral angiogram. It is considered that supratentorial and posterior fossa astrocytoma must usually exhibit different pathological tumor circulation by cerebral angiogram, since each group has distinctive clinical and biological characteristics. CT was performed in 7 of 13 cases. It appeared to be more useful than cerebral angiography in the morphological diagnosis. Especially in cystic tumors, CT produced minute information concerning peritumoral edema, enhancement of margin of cystic astrocytoma after intravenous contrast medium, and marginal enhancement with layering in the dependent part of the cyst. Neuroradiological differential diagnosis of cerebellar astrocytoma and cerebellar hemagioblastoma by CT was difficult in the cases of tumors. However, both tumors were differentiated from each other with ease by tumor stain and tumor circulation in cerebral angiography. Thus, it is concluded that cerebral angiography is superior to CT in differential diagnosis between cerebellar astrocytoma and cerebellar hemangioblastoma. (J.P.N.)