WEEK 10 Cell adaptation.pdf

8/10/2019 WEEK 10 Cell adaptation.pdf

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Cell Adaptations

PresentedBy

Ahmed El-Rashedy

Professor & Previous Headof Pathology Department

Al-Azhar University


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HyperplasiaDef: Increase in the size of the organ due to an increase in

the number of its constituent cells.Types:I) Physiologic hyperplasia:A) Hormonal-induced:1. Hyperplasia of the pregnant uteru s (estrogen-induced ).2. Hyperplasia of the female mammary ducts (estrogen-

induced ) in puberty and during pregnancy & lactation.

B) Compensatory:1. Hyperplasia of the remaining liver tissue after partial

hepatectomy.

2. Hyperplasia of the remaining kidney after nephrectomy.

Prof. Dr. Ahmed Elrashedy


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II) Pathologic (Hormonal-induced) hyperplasia:1. Thyroid hyperplasia in Graves' disease (primary thyro-

toxicosis ; thyroxin-induced ).2. Endometrial hyperplasia ( estrogen-induced ).3. Fibrocystic disease of female breast ( estrogen-induced ).4. Prostatic hyperplasia( estrogen-induced )in elderly males.

HypertrophyDef: Increase in the size of the organ due to an increase in

the size of its constituent cells.

Types:I) Physiologic hypertrophy:1. Hypertrophy of the myometrium in a pregnant uterus.

2. Hypertrophy of the skeletal muscles in athletes.



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II) Pathologic (Obstructive) hypertrophy:1. Left ventricular hypertrophy in case of aortic stenosis.2. Gastric hypertrophy in case of pyloric stenosis.3. Urinary bladder hypertrophy in case of bladder neck

obstruction by the hyperplastic prostate.Atrophy

Def: Acquired decrease in the size of an organ after its fulldevelopment.Types:I) Physiologic atrophy:

1. Involution of the pregnant uterus after labour.2. Involution of the female breast after weaning.3. Atrophy of thymus gland at 5 th year of life.4. Atrophy of the ductus arteriosus between aorta & pulmonary

artery after labor.



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II) Pathologic atrophy :A) Localized:1. Atrophy of myocardium in case of narrow coronary (ischemia).2. Atrophy of the vertebrae in case of compression by aortic

aneurysm.3. Atrophy of lower limb muscles in case of prolonged

immobilization or in case of paralysis.B) Generalized ( affecting the whole body ):1. Starvation (malnutrition).2. Ageing (Senility).

Agenesis

Def: Complete absence of an organ since embryogenesis.Aplasia

Def: Failure of development of an organ after its formation.Hypoplasia

Def: Failure of development of an organ to its full size.



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MetaplasiaDef: A change of one type of adult mature differentiated tissue

into another mature differentiated one in the same category.Types:I) Epithelial metaplasia:A) Squamous metaplasia: Change into mature differentiated

stratified squamous epithelium (SSE).a) From columnar epithelium:1. From columnar bronchial mucosa into SSE in case of heavy

smoking & in chronic bronchitis.2. From columnar gall bladder mucosa into SSE in case of gall

stones.b) From transitional epithelium: of urinary bladder mucosa in

case of urinary bilharziasis.



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B) Columnar Metaplasia:Change from stratified squamous or specific organ epitheliuminto mature simple columnar epithelium (SCE) or anotherorgan epithelium (in chronic infection).

1. Simple columnar endocervical (mucus-secreting) instead of

stratified squamous epithelium of the uterine ectocervix.2. Simple columnar colonic (goblet cell-rich) epithelium instead

of gastric columnar (pepsin & acid-secreting) epithelium ( inchronic gastritis ).

C) Serosal (Mesothelial) Metaplasia: Change from simple squamous (flat) epithelium into maturedifferentiated simple cubical or columnar epithelium.

1. Metaplasia in pleura covering the pulmonary infarct area.2. Presence of endometrial tissue (lining the uterus) on the

peritoneum

(endometriosis ).



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II) Mesenchymal (C.T.) metaplasia:1. Change of hyaline cartilage into bony tissue in ageing ( Bony

Ankylosis ) .2. Change of the skeletal muscle into bony & cartilaginous

tissue due to trauma ( Traumatic myositis ossificans ).III)Tumor metaplasia:

Change of malignant columnar

epithelium (adenocarcinoma) partially into malignant stratified squamous epithelium(Adenosquamous carcinoma ).

Traumtic myositis ossificans Adenosquamous carcinoma



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DysplasiaDef: Deranged or disordered development (dysplasia = bad molding).Sites:

Commonly in the epithelial tissues.It may be closely related to hyperplasia & thus, called Atypicalhyperplasia .It may be related to metaplasia & this is called Leukoplakia .

It is usually associated with chronic irritation or inflammation .Common Sites are:

1. Uterine cervix.2. Vulva.

3. Vagina.4. Skin.5. Oral cavity.6. Urinary bladder mucosa.7. Gall bladder mucosa.8. Respiratory mucosa.

Uterine cervical severe dysplasia (GIIIDysplasia): Intraepithelial neoplasia (CIN) :carcinoma in-situ (CIS)



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Dysplasia:Cytological Changes :

1. Loss of normal orientation of one epithelial cell to itsadjacent one.

2. Change in the cellular size & shape ( Cellular

pleomorphism ).3. Change in the nuclear size & shape ( Nuclear

pleomorphism ).4. Change in the staining character; deeply stained blue

nucleus ( Hyperchromasia ) due to increased DNAcontent.

5. Occasional appearance of mitotic figures in the nuclei.



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Dysplasia:Fate:1. Dysplasia is not necessarily precancerous.2. It is potentially reversible i.e. the epithelium may return

into normal state after removal of the factors that cause it.Grades: Depending upon the proportion of the epithelial

thickness involvement, three grades are found:1. Grade I (Mild dysplasia): involves the lower 1/3 rd of

thickness.2. Grade II(Moderate dysplasia): involves the lower 2/3rds

of thickness.3. Grade III (Severe dysplasia = Intra-epithelial neoplasia

= Carcinoma in-situ): Full thickness involvement of theepithelium by atypical cells showing cytologic features.



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Non-Neoplastic LesionsI) Heterotopia (Ectopia):Def: Presence of an organ or a tissue in an abnormal site.Examples:1. Ectopic gastric tissue in upper part oh the oesophagus.2. Ectopic gastric tissue Michel's intestinal diverticulum.

3. Ectopic adrenal cortical tissue in kidney.4. Ectopic splenic tissue (accessory spleen) in extra-splenic

sites.II) Choristoma:

Def: Microscopic normal cells or tissues in an abnormal site.Examples:1. Pancreatic tissue in the wall of stomach or small intestine.2. Adrenal cells in the kidney, ovary or lungs.


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Non-Neoplastic LesionsIII) Hamartoma:Def: Tumor-like mass of developmental origin. The

hamartomatous tissue is composed of the normally presenttissue but in haphazard arrangement.

Examples:

1. Rhabdomyoma of the heart.2. Adenomas of the liver, kidneys & pancreas.3. Developmental cysts of the lungs, kidneys & pancreas.4. Hamartoma of the lung: formed of haphazardly arranged

bronchial mucosa, cartilagenous, vascular ,fibrous &smooth muscular tissues.

5. Vascular hamartomas: Hemangiomas & Lymphangioma.6. Pigmented hamartomas (Nevi).

7. Osteochondromas (Exostosis).


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III) Hamartomas A. Vascular Hamartomas (Hemangiomas & Lymphangiomas)

Sites:

1. Skin: Face, scalp & neck.2. Mouth & oral cavity: a) Lips. b) Tongue.3. Internal organs: a)Muscles. b)Liver. c)Brain. d)Bones.Pathology:

a) Gross: Flat or elevated , Red-blue masses.b) L/M: Ectatic vascular channels either small-callipered ( Capillary

hemangiomas ) or wide & communicating ( Cavernoushemangiomas & lymphangiomas ) filled with blood & lymph

(appearing as homogenous pink ) respectively and separated by F.T.


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Hamartomas B. Pigmented Hamartomas (Nevi)

Sites:

1. Skin.2. Mucocutaneous (conjunctiva, nose & anal canal ).3. Choroid of the eye.4. Meninges.Origin:Melanocytes & Melanoblasts.Age:1) At birth ( Birth mark ).2) During childhood.3) Early adulthood.Pathology:A) Gross:1) Flat or Elevated papules.2) Hairy or Not.3) Light brown-to-black.


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Pathology:B) L/M:1) Infantile (Junctional) Nevus: Groups of

polygonal melanocytes with intracytoplasmicdark brown melanin pigment, found at thedermoepidermal junction.

2) Intradermal Nevus: Groups of the

previously described nevocytes inside thedermis.3) Compound Nevus: The nevocytic groups

are found both inside the dermis & alsoattached to the epidermis.

Relation to cutaneous neoplasms:1) Juvenile nevus: due to the extensive mitotic

activity may be mistaken for malignancy .2) Junctional adult nevus: is a precancerous

lesion.

Intradermal Nevus

Junctional Nevus

Compound Nevus



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WEEK 10 Cell adaptation.pdf

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