[Hemangiopericytoma. Apropos of a case]

Haemangiopericytomas are ubiquitous tumours with an equivocal clinical and radiological expression. They generally have a slow course and the lesions are usually revealed by a non-specific mass effect on adjacent structures. The authors report a case of subcutaneous haemangiopericytoma of the elbow which presented clinically as a vascular malformation. Amongst the various imaging techniques performed, only arteriography defined the vascular nature of the lesion and should have suggested the diagnosis of haemangiopericytoma on the basis of classically described specific signs. Instead of preserving the muscular environment, the surgical resection had to be extensive because of the poorly determined malignant potential of the tumour.