Page 39 - Concise Pathology for Exam Preparation ( PDFDrive )

24 SECTION I General Pathology

Hepatocytes showing
large cytoplasmic
vacuoles

Eccentric nuclei

FIGURE 1.14. Hepatocytes showing fatty change. The fat vacuole has pushed the nucleus into
the peripherally displaced cytoplasm (H&E; 2003).

(b) Heart
Lipid may be found in the myocardium as small droplets. Two patterns are observed
depending on the type of hypoxic stimulus:
(i) Prolonged moderate hypoxia: causes focal intracellular deposits of fat that create
grossly yellow bands of myocardium alternating with darker red-brown nor-
mal myocardium (tigered effect).
(ii) Profound hypoxia or myocarditis: affects myocytes uniformly.
3. Carbohydrates: Accumulation of carbohydrates is seen in conditions such as glyco-
genosis and mucinous degeneration.
4. Proteins:
Proteins can accumulate as
(a) Colloid droplets (reabsorption droplets in proximal renal tubules seen in renal
diseases associated with excessive protein loss in the urine).
(b) Russell bodies (active synthesis of immunoglobulins leads to excessive amounts of
secretory protein in plasma cells causing huge distension of endoplasmic reticulum,
which appear as large eosinophilic inclusions).
(c) Defective secretion and transport of proteins, as in a-1 antitrypsin deficiency,
results in accumulation of misfolded protein in ER causing ER stress as well as loss
of protein function inducing emphysema and cirrhosis.

Accumulation of Abnormal Cellular Constituents

Hyaline Change (Derived From Hyalos Glass)
It is defined as deposition of a glassy, homogenous, eosinophilic material resulting from a
variety of heterogeneous pathologic conditions. Hyaline may be
(a) Intracellular: when it is seen within epithelial cells, eg,
(i) Hyaline droplets: Observed in proximal convoluted tubules due to excessive
reabsorption of plasma proteins.
(ii) Hyaline degeneration: Hyaline deposits in voluntary muscle, eg, degeneration of
rectus abdominis.
(iii) Mallory’s hyaline: Aggregates of intermediate filaments seen in hepatocytes in
alcoholic injury.
(iv) Hyaline inclusions: Nuclear and cytoplasmic inclusions seen in viral infections.
(v) Russell bodies: Excessive immunoglobulins in endoplasmic reticulum of plasma cells.
(b) Extracellular: Seen in connective tissue, eg, hyaline degeneration in leiomyomas
(Fig. 1.15), hyaline arteriosclerosis and hyalinization of glomeruli in chronic
glomerulonephritis.

mebooksfree.com