1. Intracellular Accumulation-2 Pigments
Dr Shoaib Raza

2. Pigments They are colored substances Endogenous Exogenous
Normal constituents of the cell
Melanin
Abnormal and accumulate only under special circumstances
Endogenous
Synthesize within the body
Exogenous
Coming from outside of the body

3. Exogenous Pigments
Carbon is the ubiquitous air pollutant of urban life
Picked up by alveolar macrophages
Through lymphatic channels to regional (Hilar) lymph nodes
Causes blackening of the tissues of lung (Anthracosis)
Anthracosis + fibroblastic reaction = Coal workers pneumoconiosis
Tattooing is another exogenous pigment

6. Endogenous Pigments Lipofuscin An insoluble pigment
Wear-and-tear pigment
Lipochrome
Polymer of lipids & phospholipids
Complex with protein
Derive through lipid peroxidation of polyunsaturated lipids of subcellular membrane
Yellowish brown, finely granular, cytoplasmic (perinuclear) pigment
Seen in cells undergoing slow regressive changes
Liver & heart of aging patients

8. Melanin Endogenous, non hemoglobin derived brown black pigment
Tyrosinase catalyzes oxidation of tyrosine in melanocytes
It is the only endogenous brown black pigment
Ochronosis
Rare disorder seen in alkaptonuria,
Black pigment deposit in skin, connective tissues, cartilage, etc.

10. Hemosiderin
Hb-derived golden yellow to brown, granular or crystalline pigment
A major storage form of iron
Iron transport via transferrin
Iron + apoferritin = Ferritin micelles
Excess of iron Hemosiderin
Local excess (Common Bruises)
Heme Biliverdin Bilirubin
Systemic excess (Hemosiderosis)

13. Hyaline Change The term usually refers to:
Intracellular or intercellular alteration that gives a homogenous, glassy, pink appearance in routine H&E staining
Histological term rather than a specific form of injury
Intracellular accumulation of proteins
Collagenous fibrous tissue in old scars
Vessel wall in long standing hypertension

15. Pathologic Calcification
Abnormal tissue deposition of calcium salts
Dystrophic calcification:
Deposition occur in the dead or injured tissue
Necrosis, (Coagulative, liquefactive, caseous, fat)
Atheroma and atherosclerosis
Thrombus
Aging or damaged heart valves
Basophilic amorphous granular, sometimes clumped appearance
Intracellular, extracellular or both
Lamellated configuration = psammoma bodies

17. Pathogenesis of Dystrophic Calcification
Ca is concentrated in the cells
Ca binds to phospholipids of vesicle membrane
Phosphate is added to the calcium
Repeated cycle
Structural change generate microvesicle of calcium and phosphate groups
Dystrophic calcification is a sign of previous injury
Often cause organ dysfunction

18. Metastatic Calcification
Occur in normal tissue whenever there is hypercalcemia
Hyperparathyroidism
Destruction of bone tissue
Primary tumor of bone
Metastatic tumors to bone
Increase bone turnover
Immobilization
Vitamin D related disorders (Vitamin D intoxication)
Renal failure

19. Metastatic Calcification
May occur widely throughout the body
Interstitial tissue of gastric mucosa
Kidney
Lung
Systemic arteries
Pulmonary veins
Morphology is similar to that of dystrophic calcification

20. Aging
Result of a progressive decline in cellular function and viability caused by genetic abnormalities, & accumulation of cellular and molecular damage due to the effects of exposure to exogenous influences
Genetic factors
Diet
Social condition
Occurrence of age related disorders

21. Contribution to Cell Aging
Known changes that contribute to cell aging
Decreased cellular replication
Non-dividing state of cell, the senescence
Telomere shortening
Accumulation of metabolic and genetic damage
Cell life span is determined by a balance between oxidative damage and molecular response for repair
Ionizing radiation
Mitochondrial dysfunction
Reduction of antioxidant defense mechanism