What is the condition characterized by numerous worm-like venous collaterals parallel to a thrombosed portal vein?

The condition characterized by numerous worm-like venous collaterals that develop parallel to a thrombosed portal vein is known as cavernous transformation of the portal vein. This condition occurs as a result of chronic portal vein thrombosis, where the portal vein becomes occluded, leading to the formation of collateral circulation. The collaterals appear as serpentine, or worm-like, vessels that serve to reroute the blood flow around the obstruction, ultimately helping to maintain liver function despite the thrombosis.

In cavernous transformation, these collateral vessels can be visualized on ultrasound as they attempt to compensate for the lack of normal blood flow through the portal vein. This is a key diagnostic feature that distinguishes cavernous transformation from other conditions affecting the liver and portal circulation.

In contrast, hepatic steatosis refers to an accumulation of fat in liver cells and does not involve the formation of collateral veins. Fibrolamellar carcinoma is a type of liver cancer that typically presents with a distinct mass and not the vascular changes described. Budd-Chiari syndrome involves obstruction of the hepatic veins rather than the portal vein, which leads to different vascular changes and signs. Thus, the distinct presence of these worm-like collaterals serves as a hallmark of cavernous transformation following portal