Liu F, Rong X, Guo H, et al. - In this retrospective cohort study, researchers examined clinical characteristics, CT features, and pathological findings of pyrrolizidine alkaloid (PA)-induced hepatic sinusoidal obstruction syndrome (HSOS), also known as veno-occlusive disease. From January 2006 to September 2016, 116 individuals with PAs-induced HSOS and 68 patients with Budd-Chiari syndrome were included. Abdominal distention, ascites, jaundice, abdominal pain were common clinical manifestations of PAs-induced HSOS. In most of PAs-induced HSOS, abnormal liver function was observed. Pathological features at an acute stage were massive sinusoidal dilatation, sinusoidal congestion, erythrocytes extravasation, hepatocellular necrosis, macrophage accumulation, hemosiderin deposition. Complete loss of pericentral hepatocytes, sinusoidal dilatation, the deposition of pigment granules were noted in the subacute stage. Compared with HSOS associated with HSCT and oxaliplatin-containing chemotherapy, the PAs-induced HSOS patients showed distinct clinical features, imaging signs, and pathological characteristics.