intracellular accumulations, calcifications and cellular ageing.

1. Item-04
Intracellular Accumulations,
Calcifications and cellular
ageing
Dr. A K M Maruf Raza
Associate Professor of Pathology
Based on Robbins and Cotran
9th edition

2. Intracellular Accumulations
 Intracellular accumulation is one of the cellular
response to injury mainly due to metabolic
derangements in cells.
 Accumulation of abnormal amounts of various
substances may associated with varying
degrees of cell injury.

3. Intracellular Accumulations
 If the overload is controlled or stopped, the
accumulation is reversible. But if it is
progressive, the overload may cause cellular
injury.
 Accumulation may be of endogenous
substance (lipid, protein) or of an abnormal
exogenous substance (carbon in coal dust)

4. Substances accumulated in the
cells
 Lipids
i. Steatosis (Fatty Change)
ii. Cholesterol and Cholesterol Esters
 Proteins
 Glycogen
 Pigments
 Hyaline Change

5. Steatosis/ Fatty Change
 Steatosis or fatty change is the abnormal
accumulations of triglycerides within the cells.
 Fatty change is often seen in the liver. It also
occurs in heart, muscle and kidney.
 The causes include toxins, diabetes mellitus,
obesity. In developed countried most common
cause is Alcohol abuse.

6. Steatosis/ Fatty Change
 The causes of steatosis include toxins, protein
malnutrition, diabetes mellitus, obesity etc.
 In developed countried most common cause is
Alcohol abuse.

7. Fatty liver Microscopically

8. Cholesterol and Cholesterol Esters
accumulation
Accumulations of excess cholesterol are seen in
several pathologic processes.
i. Atherosclerosis (Blood vessels).
ii. Xanthomas (in skin, tendon).
iii. Cholesterolosis (in Gall bladder).
iv. Niemann-Pick disease, type C.

9. Pigments Accumulation
 Pigments are colored substances, some are
present normally in the cells (melanin).
 Pigments can be exogenous, coming from
outside the body or endogenous, synthesized
within the body itself.

10. Exogenous Pigments
 The most common exogenous pigment is
carbon (coal dust) found in urban air.
 Accumulations of this pigment blacken the
tissues of the lungs (anthracosis).
 Tattooing is a form of localized, exogenous
pigmentation of the skin.

11. Endogenous Pigments
Abnormal accumulation of endogenous
substances like:
i. Melanin
ii. Lipofuscin
ii. Hemosiderin (Hemosiderosis)

12. Pathologic Calcification
 It is the abnormal tissue deposition of calcium
salts with smaller amounts of iron,
magnesium, and other mineral salts.
 Two forms of Pathologic Calcification:
i. Dystrophic calcification
ii. Metastatic calcification

13. Dystrophic calcification
 Dystrophic calcification is encountered in
areas of necrosis and is almost always present
in the atheromas of atherosclerosis, damaged
heart valves.
 In dystrophic calcification serum calcium level
is normal.
 There is no derangements in calcium
metabolism.

14. Dystrophic calcification

15. Metastatic Calcification
 Metastatic calcification occurs in normal
tissues whenever there is hypercalcemia.
 There is derangements in calcium metabolism.
 May occur widely throughout the body but
principally affects the gastric mucosa,
kidneys, lungs.

16. Metastatic Calcification
 There are four principal causes of hypercalcemia:
(1) increased secretion of parathyroid
hormone (PTH)
(2) Resorption of bone tissue
(3) vitamin D–related disorders
(4) Renal failure

17. Cellular Aging
 Cellular aging is the progressive decline in
cellular function and viability.
 Usually caused by genetic abnormalities and
the accumulation of cellular and molecular
damage.

18. Cellular Aging: Mechanism
 Several mechanisms are believed to play a role
in aging:
i. Progressive DNA damage
ii. Cellular senescence (limited
replication capacity)
iii. Defective protein homeostasis
iv. Nutritional sensing (caloric restriction)

19. Thank You All