Pulmonary hypertension secondary to interstitial fibrosis with pulmonary venous lesions masquerading pulmonary veno-occlusive disease

We present a 41-year-old man with idiopathic interstitial pneumonia and pulmonary hypertension (PH) in the setting of a non-autoimmune background whose clinical presentation masqueraded pulmonary veno-occlusive disease (PVOD). Because of no histological evidence of venous occlusion in his previous lung biopsy, phosphodiesterase type-5 inhibitor was given, resulting in sudden onset of pulmonary edema. At autopsy, there were histological features of interstitial fibrosis with occlusion of the lobular septal veins and venules. Clinical presentations of PH due to interstitial fibrosis with pulmonary venous lesions may simulate those of PVOD and careful diagnostic and therapeutic approaches are required.