[Leiomyosarcoma of the inferior vena cava. Diagnostic difficulties]

As leiomyosarcomas of the inferior vena cava are extremely infrequent, the preoperative diagnosis of such tumors is rarely established. We report two cases in which the diagnosis was suggested by modern imaging prior to surgery. Three examination techniques allo contemplating this diagnosis. Ultrasound and cavography show either an intraluminal, multilobulated, roughly hyperechogenic lacuna on one of the segments of the vena cava, without any remote thrombosis image, or a complete obstruction of the vena cava with collateral circulation and a hyperechogenic right paraaortic mass. Computed tomography demonstrates the extraluminal extension. It reveals the presence of a right lateroaortic tumor with heterogeneous tissue density, in which the vena cava is concealed. The association of an intraluminal lacuna and of a tumoral syndrome on CT is highly suggestive. These three techniques are equally essential for the assessment of this tumor, which is primarily based on vascular findings. Exeresis is always difficult and the prognosis very poor.