Pulmonary veno-occlusive disease (PVOD) is a clinicopathologic syndrome that accounts for a small number of cases of pulmonary hypertension. The term was coined in 1966 (3, 4); prior to this, the terms "isolated pulmonary venous sclerosis," "obstructive disease of the pulmonary veins," or the "venous form of primary pulmonary hypertension" had been used to describe the syndrome (5, 6)..