Anomalous Inferior Vena Cava Producing Hilar Tumor

Developmental interruption of the intrahepatic segment of the inferior vena cava is an unusual anomaly. When it occurs, lower body venous return is via azygos or hemiazygos continuation, and therein lies its clinical importance. Abnormally large blood flow through the azygos system may result in dilation of the vein, causing an abnormal persistent radiodensity of the right pulmonary hilus at the azygos-superior vena cava junction.

Report of a Case  A 32-year-old Negro woman was referred for evaluation of a smoothly spherical right paratracheal radiodensity adjacent to the origin of the right stem bronchus (Fig 1 and 2). She denied all pulmonary symptoms and had considered her health good. Physical examination was normal. Complete blood count was normal, the Venereal Disease Research Laboratory test for syphilis was nonreactive; the electrocardiogram showed left axis deviation. The patient was thought to have no heart disease. Skin tests with histoplasmin, coccidioidin. blastomycin, and intermediate