Insidious Intrahepatic Portal Vein Embolism Due to Superior Mesenteric Vein Aneurysm.

There is limited information on the natural history of superior mesenteric vein (SMV) aneurysms. SMV aneurysms have the risk of aneurysm rupture due to enlargement and liver dysfunction caused by recurrent embolism. There have been a few reports of SMV aneurysms, but no clear guidelines exist regarding the management of SMV aneurysms. We report a case associated with 'silent' embolism of the intrahepatic portal vein without any clinical symptoms, which could be a part of its natural history. Accumulation of more cases is needed to more accurately understand the natural history of this rare disease.