Diagnosis of intracranial haemangiopericytomas with angiography and CT scanning.

Twenty-one primary intracranial haemangiopericytomas (HPC) were operated on from 1953 to 1983. The mean age of the 12 male and nine female patients was 38 years (17-64). Plain skull films showed well-defined bone destruction in two patients. Angiograms of 18 tumours (14 primary and four recurrent) showed the following when analysed according to the criteria of Marc et al. [4]: dual arterial supply (17/18), one-three main feeders giving rise to many irregular corkscrewlike vessels (16/18), dense, well-defined and long-lasting tumour strain (17/18), but early venous drainage rarely (1/18). The overall impression was that eight tumours appeared to be typical HPCs on angiogram. Five tumours had suggestive features, though not enough to justify specific angiographic diagnosis, and five were more like classical meningiomas. The larger tumours were more typical of HPCs, the smaller ones resembled meningiomas. CT scans of eight tumours (three primary and five recurrent) were available. The tumours were attached with a broad base to the convexity or other dural surfaces, often bilaterally. No calcifications were seen. There was little, if any, surrounding oedema. Contrast enhancement was strong and homogeneous. Four of the tumours were ring like, but the ring was thick and regular, in contrast to that in glioblastomas. The tumour margin was well-defined and smooth in three tumours, and nodular margins were seen in five; two of the latter grew extensively along dural surfaces. This sign may suggest aggressive biological behaviour. If both angiograms and CT scans are available, HPCs can be differentiated from glioblastomas and classical meningiomas, but perhaps not from anaplastic meningiomas.