Shahabaddin Sorouri - Internal Department, Mashhad University of Medical Sciences, Mashhad, Iran
Maryam Naseri - Department of Pediatrics, Mashhad University of Medical Sciences, Mashhad, Iran

Pulmonary veno-occlusive disease (PVOD) is a rare and fatal disease with non-specific clinical presentation often misdiagnosed as group ۱ pulmonary arterial hypertension (PAH). The rate of occurrence per one million people is reported to be one-tenth to two-tenths of cases, annually. Our case was a ۲۵-year-old young woman who complained of aggravation of dyspnea during exertion and slight chest pain for two months. Her work-up included pulmonary function test (PFT), an echocardiogram, body box plethysmograph test, diffusing capacity of the lungs for carbon monoxide (DLCO) test, positive ventilation/perfusion (V/Q) scan, computed tomography (CT) scan of chest, cardiac catheterization, and video-assisted thorascopic surgery (VATS). Echocardiography showed high pulmonary artery systolic pressure (PASP). The particular aspect of the present case was that due to the V/Q scan, the patient was diagnosed with chronic thromboembolic PH (CTEPH) and treated with anticoagulant, which did not have a good response. The crucial point is that in PVOD patients, V/Q scan can report segmental and subsegmental defects similar to CTEPH patients that creates a diagnostic challenge in patients. Definitive diagnosis of PVOD was based on VATS. Hypoxia, decreased DLCO, normal V/Q scan, and chest CT findings were used to diagnose PVOD. The patient’s treatment with diuretics, bosentan, and tadalafil led to the recovery of the patient’s hypoxia, saving her life for further treatment. With respect to the heterogeneous nature of the clinical presentation in PVOD patients, high clinical suspicion and appropriate diagnostic measures are required for diagnosis. The present study showed that PAH specific drugs in addition to diuretics can be used cautiously to control disease progression and save patients for lung transplantation.

Pulmonary hypertension, pulmonary veno-occlusive disease, lung transplantation