A 27-year-old man was admitted due to abdominal fullness. He had ascites and subcutaneous nodules on his head, with liver dysfunction and eosinophilia. Abdominal imaging revealed obstruction of the hepatic veins and stenosis of the inferior vena cava. Histological diagnosis of a subcutaneous nodule revealed obstructive thrombophlebitis with eosinophils. Tyrosine kinase created by fusion of the FIP1L1 and PDGFRA genes, which is characteristic of hypereosinophilic syndrome (HES), was detected. He was diagnosed with Budd-Chiari syndrome associated with HES. Liver function tests improved after interventional therapy followed by steroid therapy. It is important to diagnose the cause of Budd-Chiari syndrome.
2007 by The Japanese Society of Internal Medicine