Hepatobiliary and pancreatic: Idiopathic portal hypertension

Abstract

A Sicilian man, aged 65, was admitted to hospital with melena. Ten years previously, he had been diagnosed with limited cutaneous systemic sclerosis (CREST syndrome). His treatment had included nifedipine patches for Raynaud's phenomenon and intermittent short courses of low-dose prednisolone. There were no risk factors for viral hepatitis and he rarely consumed alcohol. Liver function tests were normal apart from a mild elevation of alanine aminotransferase (76 U/l). Endoscopy was performed after resuscitation with fluids and blood and revealed four columns of esophageal varices (grade II) with active bleeding as well as endoscopic features of portal gastropathy. Bleeding settled after treatment with endoscopic band ligation and the administration of intravenous glypressin. Screening tests for various causes of cirrhosis were negative but he was weakly positive for anti-centromere antibody and rheumatoid factor. A Doppler ultrasound study showed a normal liver, an enlarged spleen and a patent portal vein with hepatopetal flow. These findings were confirmed on a contrast-enhanced computed tomography scan (Figure 1). A percutaneous liver biopsy was performed. There were no features of cirrhosis on the reticulin stain but more detailed examination of the portal tracts demonstrated variable fibrosis without inflammation (Figure 2 left, H&E x40) and absence of portal vein branches (Figure 2 right, H&E x80). The diagnosis was that of idiopathic portal hypertension. Idiopathic portal hypertension is a diagnosis of exclusion characterized by portal hypertension in the absence of cirrhosis, portal vein thrombosis and schistosomal infection. The majority of patients present with bleeding esophageal varices but alternative modes of presentation include splenomegaly and thrombocytopenia. The cause of the disorder remains unclear but one possibility is thrombosis or vasculitis that involves small branches of the portal vein. This hypothesis is supported by the histological findings of a degree of portal fibrosis as well as a paucity or absence of portal veins in portal tracts. Case reports have described associations with various infections, toxins and autoimmune diseases. These have included reports of an association between idiopathic portal hypertension and systemic sclerosis in Japanese women but, to our knowledge, this is only the second case report in a male. One possibility is that abnormal immune responses and vascular damage that appear to be central to the pathogenesis of scleroderma can sometimes involve small portal veins within the liver causing portal hypertension without cirrhosis.