Case report: pulmonary veno-occlusive disease: a rare but fatal cause of pulmonary hypertension in a patient following allogeneic stem cell transplantation.

Pulmonary veno-occlusive disease (PVOD) represents a rare and challenging form of pulmonary hypertension, characterized by preferential remodelling of the pulmonary venules. PVOD may be idiopathic as well as related to other conditions with environmental and genetic factors contributing to its development. Recently, bi-allelic mutations in the EIF2AK4-gene have been identified as a cause of heritable PVOD. PVOD shares an overlapping disease phenotype with pulmonary arterial hypertension (PAH) and is regularly misdiagnosed as such, although differentiation between these two conditions is important because of the different prognosis and therapeutic approach. The diagnosis of PVOD is frequently delayed because of the complex diagnostic process. The gold standard remains histology with widespread obliteration of small pulmonary veins by fibrous intimal thickening and patchy capillary proliferation as the pathological hallmark. At present, neither treatment guidelines nor curative medical therapies are available for PVOD. Because of the progressive nature of the disease, a quick referral for lung transplantation remains the only definitive therapy in subjects below the age of 65.