[Veno-occlusive disease of the lung]

This paper is a review of current data on a rare pathology which causes primary pulmonary arterial hypertension: pulmonary veno-occlusive disease. The manifestations of the disease consist of dyspnoea of progressive onset, crepitations in the lower pulmonary lobes and diffuse interstitial syndrome with Kerley's B lines. These signs are associated with severe hypoxia and severe pulmonary arterial hypertension with paradoxically normal wedge pressure. Pathological specimens must be obtained to confirm the diagnosis. They show thrombosis of pulmonary veins less than 2 mm in diameter and sometimes of arterioles, presence of connective tissue with few cells and images of recanalization, muscularization of pulmonary arterioles, lesions of interstitial nodular fibrosis and presence of haemosiderin-rich macrophages. The disease is frequently associated with other pathologies, including heart disease, blood disease and pulmonary capillary haemangiomatosis. In recent years, veno-occlusive disease has been found to occur immediately after chemotherapy for cancer and bone marrow or kidney transplantation. Three physiopathological hypotheses have been put forward to explain the disease: infection, autoimmune reaction and toxic reaction.