Passive congestion - microscopy image

Passive congestion consists in an increased quantity of blood present in a territory due to difficulties in venous blood flow. It may be generalized or localized, acute or chronic. The liver, like the lung, is one of the first organs to suffer from generalized congestion. Major causes of passive hepatic congestion include global or right cardiac failure. The microscopic appearance of a liver with passive congestion depends on the severity of the condition and on its evolution. In the initial stages, illustrated by the image, only blood accumulation in the centrilobular vein and sinusoids can be seen (H&E, 100x).