week 5 degenerations.pdf

8/10/2019 WEEK 5 Degenerations.pdf

1/25


2/25

Degenerations

PresentedBy

Ahmed El-Rashedy

Professor & Previous Headof Pathology DepartmentAl-Azhar University


3/25

Degeneration

Def.: An abnormal disturbance of metabolism associated

with reversible morphological changes on exposure of aliving tissue or cells to non-lethalirritants.

Types of irritants:

1. Hypoxia.

2. Chemical agents: Air pollutants & hydrocarbons.

Hypertonic solutions.

Poisons: Cyanide, Mercury, Arsenic.

Insecticides.

Fungicides.

Industrial vapors or fibers (Asbestos, silica).

Drugs: Narcotics.

Prof. Dr. Ahmed Elrashedy


4/25

Types of irritants:

3. Physical agents:

Mechanical trauma or crush injury.

Extremes of temperature (excess heat or severe coldness).

Irradiation whether ionizing (cobalt, gamma) or non-

ionizing (X-, ultraviolet) rays.

Electric shock.

4. M icro-organisms(viable agents):

Bacteria.

Viruses.

Fungi.

Parasites.

Rickettsia.



5/25

Types of irritants:

5. Immunologic disorders:

Hypersensitivity to a foreign protein (injectable,

ingestible, inhaler).

Hypersensitivity to a self- antigen as extrusion of

eye lens protein or sperm head protein in obstructedepididymis.

6. Genetic diseases:

Sickle cell anemia: production of Hb-S instead ofHb-A.

Downs syndrome (Mongolism): aberration in

chromosome no; 21.



6/25

Types of irritants:

7. Nutr i tional disorders:

Hyper- or Hypo- vitaminosis A & D. Protein-Calorie deficiency: Marasmic baby

(Kwashiorkor' s disease).

Fat-rich diet intake: Obesity & atherosclerosis.Sites of degeneration:

Parenchymatous organs because they contain highly

active & energy producing cells. These organs are:1. Liver (H epatocytes).

2. Kidney (Renal tubular cells).

3. Heart ( Cardiac muscle cells).



7/25

Cloudy Swelling

(Hydropic Degeneration=Ballooning

Degeneration=Vacuolar Degeneration)Def.: An abnormal accumulation of water inside the living cell.

Pathogenesis: Hypoxia (or ischemia) Early mitochondrial

condensation Mitochondrial swelling lack in energy supply

causing failure of sodium /potassium pump Retention ofsodium inside the cell Increase of intracellular osmotic pressure

with imbibation of water from extracellular compartment

producing droplets of water within the cytoplasm (fine granules

representing swollen mitochondria = Cloudy swell ing). Then, large

vacuoles (representing distended endoplasmic reticulum)

accumulate within the cell Clear cytoplasm (Hydropic

degeneration).



8/25

Pathology:

A) Gross: The affected organ becomes:

1. Color: Pale.

2. Size: Enlarged (Swollen).3. Weight: Increased (Heavy).

4. Cut surface: Bulges over the capsule.

B) L/M (in kidney):

1. Renal tubules: Size: Swollen &enlarged.

L ining cell s:

Shape: Pyramidal (normally cubical).

Cytoplasm: Pale, granular or clear.

Lumen of tubules:

Star-shaped or obliterated (normally patent, oval

& regular).

2. Capil laries in-between the swoll en tubules:

Compressed.


P f D Ah d El h d


9/25

B) E/M (in kidney):1. Changes in cell membrane: Cellular swelling. Loosening of intercellular attachments

(Desmosomes). Formation of myelin fingers. Blunting & distortion of microvilli.2. Changes in cytoplasmic organelles: Mitochondrial swelling with indistinct

cristae, double short basal infoldingmembrane with bizarre mitochondria,rupture & calcification.

Deformed Golgi zone.

Lysosomal swelling. Dilated rough endoplasmic reticulum. Detached free ribosomes & protein

synthesis. Cytoplasmic droplets & clear vacuoles

of water.



10/25

Electron micrograph showing:

(a) Proximal convoluted tubule cell

with focal loss Brush Border (BB),

numerous apical vesicles (V),numerous lysosome (L) deformed

Golgi zone (G), nucleus (N) with

marginal heterochromatin in dense

cytoplasm.

(b) Swollen round mitochondria (M)

with indistinct cristae, vesicles (V)

and secondary lysosome (L).

(c) Apoptotic cell with nucleus have

invaginated nuclear envelope andheterochromatin condensation.

(d) Double short basal infolding

membrane (arrows) with bizarre

mitochondria (M)


f h d El h d


11/25

Electron micrograph showing:

(a) Part of tubule cell reveals normal

Brush Border (BB), small lysosome

(L), nucleus (N) and large elongated

mitochondria (M) in-between

extended basal infolding (arrows).

(b) Details intact Brush Border (BB)

and well developed vesicles (V).

(c) Details part of nucleus (N) with

peripheral heterochromatin,

lysosome (L), homogenousmitochondria (M) with normal

cristae, double membrane basal

infolding (arrow) & free ribosome

(R).


P f D Ah d El h d


12/25

Fatty changes (Fatty Degeneration)

Def.: An abnormal accumulation of fat within the parenchymatous cells.

Sites:

1. Liver.2. Heart & muscles.

3. Kidney.

Pathogenesis:

Excess accumulation of triglycerides within the liver due to one of the

followings:

1. Excess free fatty acid entry into the liver.

2. Excess FFA synthesis from acetate.

3. Increased FFA esterification into triglycerides (through

glycerophosphate).

4. Decreased FFA oxidation.

5. Decreased apoprotein synthesis (Apoprotein normally conjugates

with triglycerides to form lipoprotein).

6. Impaired lipoprotein secretion from the liver.



13/25

Causes of Fatty liver:

1. Chronic alcoholism (Hepatotoxicmethyl alcohol drinking).

2. Protein malnutrition (starvation).3. Diabetes mellitus.

4. Obesity.5. Hepatotoxic chemicals: as carbon

tetrachloride& phosphorus.


P f D Ah d El h d


14/25

Pathology:

I) Liver:

Gross:

1. Mild:No abnormality.2. SevereFatty liver:

Size: Enlarged.

Color: Yellowish.

Consistency: Soft& greasy.

Outer Surface: Smooth.

Border: Round.

Differential Diagnosis:

Amyloid liver :

Size: Enlarged. Color: whitish.

Consistency: Firm & waxy.


Border: Sharp.


P f D Ah d El h d


15/25

L/M:

1. Early:

Small fat vacuoles in the cytoplasm nearthe nucleus.

2. Later :

Union of these vacuoles to give clear

spaces displacing the nucleus into the

periphery against the cell membrane

(Signet r ing appearance).

3. Late:

Rupture of the fat-filled hepatocytes with

union of the fat globules together giving

fatty cysts.


Prof Dr Ahmed Elrashedy


16/25

II) Heart: (Tabby Cat Str iations) or (Thrush

Breast):

Occurs in case of chronic or severe anemia(due to a prolonged moderate ischemia).

Gross:

Size: Enlarged.

Color & Pattern: Alternating layers of

yellowishfatty myocardial fibers & dark red-

brown congested uninvolved fibers.

Consistency: Soft.


L/M:

Similar to those detected in the liver.




17/25

Identification of fatty globules:

1. Hematoxylin & Eosin stain: Clear vacuoles

(dissolution of fat by xylene used in preparing

the slide).2. Sudan IV & Red oil stains: Bright-red globules.

3. Osmic acid & Sudan black : Black fatty

vacuoles.

N.B.:Fatty ingrowth or stromal fatty

infiltration: An abnormal accumulationof fat within the stromal C.T. cells.It occurs in obesity.

Sites:1. Pancreas: Fat in the C.T. septa of the

pancreatic lobules.2. Heart: Fat in the C.T. in-between the

muscle bundles.




18/25

Hyaline Change (Hyaline Degeneration)Def.: Abnormal accumulation of Proteinaceous

homogenous structureless translucent materialinside the living cell.

Cause: Disturbance in the protein metabolisminside the cell.

Chemical Nature:Protein-Phospholipid Complex.

Examples:1. Kidney:Hyaline droplets within the proximal

renal convoluted tubular cells.2. Liver: Hyaline droplets within the

hepatocytes in alcoholic cirrhosis (Mallory

bodies).3. Brain: Cytoplasmic round, oval or bullet shaped inclusion viral particles called Negribodies in the neurons.

4. Plasma cells: Hyaline spherical droplets

withinthe plasma cells calledRussell bodies.




19/25

5. Diaphragm & Rectus abdominis muscle:

(Zenkers Degeneration)

Cause:

A complication of typhoid fever.Pathology:

A) Gross:The involved muscle is:

1. Friable.

2. Pale.3. May rupture giving minute hemorrhages.

B) L /M :

I ) Early:

1. Swollen homogenous pink muscle fibers.2. Loss of striations.

I I ) Late:

Necrosis with loss of the cellular details

with fragmentation or lysis of their nucleus.

Zenkers

Degeneration



20/25



21/25

Damage of F ibers

1. F ibrosis

Def.: Excess formation of mature collagen fibers.

Examples:

1. Nodal fibrosis: in L.N. draining an area of

chronic infection.

2. Bilharzial liver fibrosis.

3. Liver cirrhosis.4. Pulmonary fibrosis.

2. Elastosis

Def.: Formation of elastic fibers.

Examples:1. Normal Skin following a prolonged exposure

to ultraviolet light.

2. Skin cancer following a prolonged sunlight

exposure.

Bilharzial liver fibrosis

Pulmonary fibrosis

( Masson trichrome)

Elastosis


Pro . Dr. A me E ras e y


22/25

3. Hyalinosis (Extracellular H yaline Change)Def.: Abnormal extracellular accumulation of hyaline

material.

Pathogenesis:

A. C.T. Hyalinosis: Fusion of the collagen fibers.

B. Vascular Hyalinosis: Leakage of plasma proteins

through the damaged endothelium into the interior of

arterial wall.

Examples:I) C.T. hyalinosis:

1) Hyalinosis of collagen fibers in old scar.

2) Hyalinosis of splenic capsule & trabeculae in congestive

splenomegaly.

3) Neoplastic Hyalinosis: e.g. as secondary change infibromyoma (leiomyoma).

II) Vascular hyalinosis:

1. Arteriolar wall hyalinosis: in renal benign HPT & in

diabetes.

2. Glomerular hyalinosis: in chronic glomerulonephritis.

. D . m E y



23/25

4. F ibrinoid Necrosis

Def.: It is a descriptive process including:

1) Swelling of the collagen fibers.

2) Fragmentation of these fibers.

3) Degeneration of the collagen fibers (increased

eosinophilia).

Examples:1. Collagen Diseases: as

Systemic Lupus (SLE).

Systemic sclerosis.

Rheumatoid arthritis.

Polyarteritis nodosa (PN).

2. Malignant Hypertension.

3. Rheumatic endocarditis (Ashoff Nodules).

Ashoff Nodules




24/25

Damage of Matr ix

Myxomatous Degeneration

Def.: Pathological condition characterized by increase in

the ground substance + degeneration of the stromal

fibers.

Pathology:

Gross:

Soft, jelly-like tissue resembling

Wharton jelly of the umbilical cord.L/M:

Star or stellate-shaped branching

cells interlacing with each other found in a faint blue

mucopolysaccharide matrix.

Example: Myxomatous degeneration occurring as a 2ry change in

fibromyoma.

D.D.: Myxedema:

Only an increase in the ground substance appearing as

homogenous blue material.

y


25/25


week 5 degenerations.pdf

Documents