Page 38 - Concise Pathology for Exam Preparation ( PDFDrive )

1 Cell Injury and Cell Death 23

Mechanism of development of fatty liver is shown in Flowchart 1.13.

Diet Peripheral fat depots

1 Free fatty acids Acetate

3 Oxidation
2 Free fatty acids Ketone bodies
(Liver)
Alpha glycerophosphate 4
Phospholipids
Triglycerides
Cholesterol esters
Apoproteins 5

Lipoproteins

6 Plasma lipoprotein
FLOWCHART 1.13. Mechanism of development of fatty liver.
1. Excessive entry of free fatty acids into the liver (starvation, toxins, dia-
betes mellitus, anoxia).
2. Increased synthesis of free fatty acids in the liver (obesity, alcohol
abuse).
3. Decreased oxidation of fatty acids into ketones (anoxia, starvation).
4. Increased esterification of fatty acids into triglycerides (alcohol).
5. Decreased synthesis of apoproteins (CCL4 toxicity, protein energy mal-
nutrition).
6. Defective excretion of lipoproteins.

Morphological features associated with fatty change
(a) Liver
Gross pathology: In diffuse fatty change the organ appears enlarged, pale, soft, yel-
low and greasy. Focal fatty change is seen as yellow mottling.
Microscopy (Fig. 1.14; Flowchart 1.14)

Liver liposomes
(diffuse minute membrane-bound inclusions)

Microvesicular fatty change
(small vacuoles around the nucleus)

Macrovesicular fatty change (vacuoles coalesce to form larger
vacuoles, pushing the nucleus to the periphery)

Rupture of contiguous cells

Formation of fatty cysts
FLOWCHART 1.14. Sequence of events in the evolution of fatty liver.

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