Image Based Question-69888

A sectioned slice of liver is shown in the image.From the following given options,which is true regarding pathogenesis of this condition of liver?

A. Increased entry of free fatty acids into the liver

B. Decreased conversion of fatty acids into ketone bodies

C. Block in the excretion of lipoprotein from the liver into plasma.

D. All of the above

Correct Answer » D Explanation

Ans:D. All of the above.

Fatty liver is shown in the image.

FATTY LIVER

MORPHOLOGIC FEATURES:

• Grossly, the liver in fatty change is enlarged with a tense, glistening capsule and rounded margins.
• The cut surface bulges slightly and is pale-yellow to yellow and is greasy to touch .

Microscopically, characteristic feature is the presence of numerous lipid vacuoles in the cytoplasm of hepatocytes.

Fat in H & E stained section prepared by paraffin embedding technique appear non-staining vauloes because it is dissolved in alcohol :

• The vacuoles are initially small and are present around the nucleus (microvesicular).
• But with progression of the process, the vacuoles become larger pushing the nucleus to the periphery of the cells (macrovesicular).
• At times, the hepatocytes laden with large lipid vacuoles may rupture and lipid vacuoles coalesce to form fatty cysts.
• Infrequently, lipogranulomas may appear consisting of collections of lymphocytes, macrophages, and some multinucleated giant cells.
• Fat can be demonstrated in fresh unfixed tissue by frozen section followed by fat stains such as Sudan dyes (Sudan III, IV, Sudan black) and oil red O. Alternatively, osmic acid which is a fixative as well as a stain can be used to demonstrate fat in the tissue.

PATHOGENESIS:

In fatty liver, intracellular accumulation of triglycerides can occur due to defect at one or more of the following 6 steps in the normal fat metabolism :

• Increased entry of free fatty acids into the liver.
• Increased synthesis of fatty acids by the liver.
• Decreased conversion of fatty acids into ketone bodies resulting in increased esterification of fatty acids to triglycerides.
• Increased α-glycerophosphate causing increased esterification of fatty acids to triglycerides.
• Decreased synthesis of ‘lipid acceptor protein’ resulting in decreased formation of lipoprotein from triglycerides.
• Block in the excretion of lipoprotein from the liver into plasma

Even a severe form of liver cell dysfunction may be reversible; e.g. an alcoholic who has not developed progressive fibrosis in the form of cirrhosis, the enlarged fatty liver may return to normal if the person becomes teetotaller.