Liver Pigmentation

Various substances and conditions can cause pigmentation of the liver.

Congenital melanosis

Can occur in calves and lambs at birth. It is not related to clinical disease. Black discolouration occurs in the capsule and stroma of the liver and these are an abnormal accumulation of melanin pigments.

Haemosiderin

Acuumulation of this pigment occurs in chronic passive congestion and surrounding areas where there has been prior necrosis and haemorrhage. The pigment is found within the Kupfer cells (macrophages of the liver) and this can be visualised using Perl's Prussian Blue stain.
The condition does not cause clinical signs alone, but is the consequence of haemorrhage so this will cause clinical signs. Deposition of large amounts of haemosiderin may result in liver failure.

Lipofuscin

Is a pigment of cellular ageing (it is also names the 'senility pigment') and is insoluble and golden brown in colour.
It occurs within heptatocytes and can be identified using Schmorl's stain where the pigment will appear dark blue. It is commonly seen in hepatocytes near to the centrilobular vein in older cats and is of no clinical significance.

Bile

Bile pigment discolours tissues green and therefore is very noticeable at necropsy. Often, intrahepatic bile caniculi are distended with a greenish pigment and are known as 'bile lakes'. Larger foci are seen in long standing cases when the hepatocytes rupture: the discharged bile is then surrounded by macrophages and perhaps giant cells.
Bile can be stained with Fouchet stain - and appears green. Bile pigmentation is especially prominent in obstructive jaundice. Underlying causes must be addressed for treatment of this condition.

Test yourself with the Liver Pathology Flashcards

Liver Pathology Flashcards