An Autopsy Case of Pulmonary Veno-Occlusive Disease Complicated with Chronic Obstructive Pulmonary Disease and Severe Pulmonary Hypertension.

Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory lung disease with obstructed airflow and frequently causes secondary mild-moderate pulmonary hypertension (PH). However, a low proportion (1%-5%) of COPD patients develop severe therapy-resistant PH, and it is crucial to determine whether the patient has another disease capable of causing severe PH, including pulmonary arterial hypertension.Here, we describe a case of a 71-year-old male with COPD complicated by severe PH and right heart failure. He had a history of heavy smoking and developed progressive hypoxemia on exertion. He had severe airflow limitation (forced expiratory volume % in one second, FEV 1.0% = 42.8%) with a markedly reduced diffusing capacity of the lung (predicted diffusion capacity of carbon monoxide, %DLCO = 29%), and high-resolution computed tomography (CT) demonstrated significant lung parenchymal abnormalities such as diffuse interlobular septal thickening, ground-glass opacities, and enlarged mediastinal lymph nodes. He was diagnosed with group 3 PH caused by COPD but resistant to the treatment of COPD, diuretics, and oxygen therapy. Pathohistological analysis of autopsy specimens revealed the coexistence of interstitial fibrosis and partial occlusion of the small intrapulmonary veins, which led to a conclusive diagnosis of pulmonary veno-occlusive disease (PVOD).Because of its rarity and similarity with idiopathic pulmonary arterial hypertension, PVOD is difficult to diagnose antemortem and has a poor prognosis. High-resolution CT findings (septal thickening, ground glass, and enlarged lymph nodes) and severely reduced DLCO should be carefully evaluated for the early detection and treatment of PVOD in COPD patients with severe PH.