A Zahn infarct is a pseudo-infarction

Infarction

In medicine, infarction refers to tissue death that is caused by a local lack of oxygen due to obstruction of the tissue's blood supply. The resulting lesion is referred to as an infarct.-Causes:...

 of the liver

Liver

The liver is a vital organ present in vertebrates and some other animals. It has a wide range of functions, including detoxification, protein synthesis, and production of biochemicals necessary for digestion...

, consisting of an area of congestion with parenchymal atrophy but no necrosis

Necrosis

Necrosis is the premature death of cells in living tissue. Necrosis is caused by factors external to the cell or tissue, such as infection, toxins, or trauma. This is in contrast to apoptosis, which is a naturally occurring cause of cellular death...

, and usually due to obstruction of a branch of the portal vein. According to Dr. Shirley Siew, a distinguished pathologist from Michigan State University, this may also be an obstruction of the hepatic artery

Hepatic artery

Hepatic artery can refer to:* Common hepatic artery * Hepatic artery proper...

. Zahn infarcts are unique in that there is collateral congestion of liver sinusoid

Liver sinusoid

A liver sinusoid is a type of sinusoidal blood vessel that serves as a location for the oxygen-rich blood from the hepatic artery and the nutrient-rich blood from the portal vein....

s that do not include areas of anoxia seen in most infarcts. Fibrotic tissue may develop in the area of the infarct and it could be caused by an occlusive phlebitis

Phlebitis

Phlebitis is an inflammation of a vein, usually in the legs.When phlebitis is associated with the formation of blood clots , usually in the deep veins of the legs, the condition is called thrombophlebitis...

 in portal vein radicles.