Ultrastructural analysis of the liver with portal vein agenesis: A case report

Congenital absence of portal vein (CAPV) is a rare vascular malformation: a ll 16 cases up to now reported are associated with other congenital anomali es and with benign or malignant hepatic neoplasms. Our report concerns a gi rl with a complex malformative syndrome consisting of CAPV, nodular tumor-l ike hyperplasia of the liver, and multicystic kidney dysplasia. CAPV was di agnosed by angiography, showing the splenic vein and superior mesenteric ve in joined to form a "common trunk" directly entering the inferior vena cava above the liver. The liver maintained the normal lobular architecture, but immunohistochemical and ultrastructural observations revealed abnormalitie s of the hepatocyte membranes and diffuse capillarization of the sinusoids. In this paper, we present the relationship between the tissue modification and the lobular microcirculation changes due to CAPV, with exclusive perfu sion of arterial blood flow.