Pulmonary varix--pathognomonic appearance.

A well defined lung mass with clear margins and no other signs such as lymphadenopathy, pulmonary infiltration, consolidation, collapse or bone involvement usually indicates a benign lesion, whether a tumour such as an adenoma (carcinoid), cyst or vascular abnormality. Bronchogenic, pericardial and hydatid cysts do not show contrast enhancement, adenomas do enhance but not as significantly as vascular lesions. In this patient not only was the enhancement ofthe mass similar to the cardiac chambers but there was a vein entering the mass and a connection with a left pulmonary vein. Pulmonary varix is a recognized, albeit uncommon, complication of mitral valve disease.