Page 55 - Textbook of Pathology, 6th Edition

turns macrophages into foam cells. The examples are as 39
follows:
1. Fibrofatty plaques of atherosclerosis (Chapter 15).
2. Clusters of foam cells in tumour-like masses called
xanthomas and xanthelasma.

Stromal Fatty Infiltration CHAPTER 3

This form of lipid accumulation is quite different from fatty
change just described. Stromal fatty infiltration is the
deposition of mature adipose cells in the stromal connective
tissue in contrast to intracellular deposition of fat in the
parenchymal cells in fatty change. The condition occurs most
often in patients with obesity. The two commonly affected
organs are the heart and the pancreas. Thus, heart can be the
site for intramyocardial fatty change as well as epicardial
(stromal) fatty infiltration. The presence of mature adipose
cells in the stroma generally does not produce any
dysfunction. In the case of heart, stromal fatty infiltration is
associated with increased adipose tissue in the epicardium. Cell Injury and Cellular Adaptations

INTRACELLULAR ACCUMULATION OF PROTEINS
Pathologic accumulation of proteins in the cytoplasm of cells
Figure 3.17 Fatty liver. Sectioned slice of the liver shows pale yellow
parenchyma with rounded borders. may occur in the following conditions:
1. In proteinuria, there is excessive renal tubular reabsorp-
iv) Infrequently, lipogranulomas may appear consisting of tion of proteins by the proximal tubular epithelial cells which
collections of lymphocytes, macrophages, and some multi- show pink hyaline droplets in their cytoplasm. The change
nucleated giant cells. is reversible so that with control of proteinuria the protein
v) Fat can be demonstrated in fresh unfixed tissue by droplets disappear.
frozen section followed by fat stains such as Sudan dyes 2. The cytoplasm of actively functioning plasma cells shows
(Sudan III, IV, Sudan black) and oil red O. Alternatively, pink hyaline inclusions called Russell’s bodies representing
osmic acid which is a fixative as well as a stain can be synthesised immunoglobulins.
used to demonstrate fat in the tissue. 3. In α -antitrypsin deficiency, the cytoplasm of hepatocytes
1
shows eosinophilic globular deposits of a mutant protein.
Cholesterol Deposits
4. Mallory’s body or alcoholic hyalin in the hepatocytes is
Intracellular deposits of cholesterol and its esters in macro- intracellular accumulation of intermediate filaments of
phages may occur when there is hypercholesterolaemia. This cytokeratin and appear as amorphous pink masses.

Figure 3.18 Fatty liver. Many of the hepatocytes are distended with large fat vacuoles pushing the nuclei to the periphery (macrovesicles),
while others show multiple small vacuoles in the cytoplasm (microvesicles).