Veno-occlusive disease of the liver induced by low-dose cyclophosphamide

A 2-yr-old child with idiopathic pulmonary hemosiderosis and autoimmune thrombocytopenia developed hepatic veno-occlusive disease after being treated with long-term, low-dose cyclophosphamide. The authors believe that the injury was induced by cyclophosphamide. Although transplant dosages of cyclophosphamide alone or in conjunction with other drugs have been shown to induce hepatic venocclusive disease, this is the first case of hepatic venocclusive disease associated with nontransplant dosages of cyclophosphamide. Histopathologically, the injury was characterized by occlusive lesions of intrahepatic veins, both the terminal hepatic venules and portal veins branches, together with necrosis (predominately involving Zones 3 and 2) and hemorrhages. An added risk factor could have been release of platelet-derived growth factor that in turn activated and promoted proliferation of fibroblasts and smooth muscle cells in the vessels. Previously reported cases of cyclophosphamide-related injury are reviewed.