Concomitant pulmonary arteriovenous and inferior vena cava malformations. A case report.

A case of pulmonary arterio-venous malformation (AVM) presenting with dyspnoea diagnosed by computer tomography (CT) and pulmonary angiography is reported. Venous anomalies in the form of agenesis of the iliac veins and the inferior vena cava (IVC), were discovered through femoral venograms performed after technical difficulties were encountered at pulmonary angiography performed via the femoral route. These venous anomalies co-existed with normal but dilated azygos and hemiazygos systems, and with the azygos appearing as a right hilar mass lesion which showed the "candy cane sign" on the lateral view on venography. A dilated varix at the confluence of the right renal vein and the IVC collaterals was also noted. This association of a pulmonary AVM and IVC agenesis has not been previously reported in the literature. The embryogenesis of the inferior vena cava and the azygos system is presented in an attempt to explain the rare association of these anomalies. The various techniques of diagnosing the disease entities, especially by CT, are discussed. The rare co-existence of pulmonary AVM and the absence of the IVC is emphasized.