Systemic to pulmonary venous shunt in lung cancer with obstruction of superior vena cava: case report with review of the literature.

We describe the CT features of an unusual collateral pathway of systemic to pulmonary venous shunt in a patient with lung cancer that obstructed the superior vena cava (SVC). Spiral CT scan with rapid injection of contrast medium from a right arm vein revealed a systemic to pulmonary venous shunt (SPVS), passing through thick pleural effusion, which was the direct transpleural communication between right upper chest wall veins and right superior pulmonary veins. Three-dimensional CT angiography revealed the entire shunt. We consider that the shunt was formed in association with radiation therapy, and was not injured with the subsequent collapse of the lung and accumulation of massive pleural effusion. We review the reports that have dealt with the shunt in patients with lung cancer, and discuss the conditions related to the development of SPVS in such patients.