Liver hydatidosis disease with portal vein invasion: Report of a rare case and review of literature.

Hydatid disease is a zoonosis caused by Echinococcus granulosus. Humans are aberrant intermediate hosts and following the infection, the parasite may infest any organ of the body, with the liver and lungs being the most involved organs. Portal vein involvement by hydatid cyst disease is extremely rare with only seven cases published to our knowledge. We present a 62-year-old Persian male with an incidental liver cyst. His laboratory tests were in normal ranges. The ultrasonography (US), computed tomography (CT) and magnetic resonance imaging (MRI) findings show hydatid disease of the liver with distal portal vein involvement and collateral venous formations. The patient is being followed and has not gone under surgery yet. It possesses a propensity to invade multiple organ systems, notably the liver and lungs. Hydatid disease is imposing a significant burden on healthcare systems specifically in developing countries. Manifestations of the disease are often non-specific, while a subset of the infected population remains asymptomatic. Portal vein invasion and obstruction is a rare complication, and it is important to distinguish it from vein thrombosis, as the management of these entities requires different approaches.