Neoplasia-2Neoplasia-2

Precancerous lesionsPrecancerous lesions1.1. Metaplasia:Metaplasia:

a. Squamous metaplasia Squamous cell carcinoma.

b. Glandular metaplasia Adenocarcinoma.

2. Benign tumors:2. Benign tumors:

a. Thyroid adenoma thyroid carcinoma.

b. Transitional cell papilloma transitional cell

carcinoma.

3. Hyperplasia: 3. Hyperplasia:

•Endometrial hyperplasia leads to endometrial carcinoma.

•Mammary hyperplasia leads to cancer breast.

4. Liver cirrhosis: 4. Liver cirrhosis: leads to hepatocellular carcinoma.

5. Paget’s disease of bone: 5. Paget’s disease of bone: leads to osteosarcoma.

6. Crytorchidism (undescended testis): 6. Crytorchidism (undescended testis): leads to

seminoma.

7. Xeroderma pigmentosa: 7. Xeroderma pigmentosa: leads to melanoma.3

Co-carcinogensCo-carcinogens- Means the factors help the occurrence of cancer.

1. Age:1. Age:

- With aging there is a more chance of exposure to the

carcinogen.

2. Sex:2. Sex:

-Most of tumors are common in male.

3. Diet:3. Diet:

-Excess fat may be related to cancer colon.

-Smoked fish may be related to cancer stomach.

4. Environmental factors:4. Environmental factors:

a. Cigarette smoking related to cancer tongue, larynx,

lung, kidney and urinary bladder.

b. Excess sun exposure: related to cancer skin.

c. Alcoholism: cancer mouth and esophagus.

5. Heredity:5. Heredity:

•Some tumors are inherited i.e. cancer breast and cancer

colon

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Carcinogenic agentsCarcinogenic agents

1.1. Chemical carcinogens:Chemical carcinogens:

a. Beta-naphthylamine cancer bladder.

b. Aflatoxins produced from aspergillus

fungus liver cancer.

c. Nitrosamine cancer stomach.

2. Viral carcinogens:2. Viral carcinogens:

•Hepatitis B virus hepatocellular carcinoma.

•Human papilloma virus (HPV) cancer cervix.

•Ebstein barr virus (EBV) nasopharyngeal

carcinoma and lymphoma.

3. Radiation carcinogens3. Radiation carcinogens:

a. Ionizing radiation: leukemia.

b. Ultraviolet rays (prolonged exposure to sunlight): cancer

skin.

4. Hormonal carcinogens:4. Hormonal carcinogens:

a. Estrogen: cancer breast and cancer endometrium.

b. Androgen: cancer prostate.

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Morphology of Malignant tumorsMorphology of Malignant tumors

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CarcinomaCarcinoma is malignant tumor arising from epithelium.

* Examples: •Squamous epithelium squamous cell carcinoma.

•Glandular epithelium adenocarcinoma.

•Transitional epithelium transitional cell carcinoma.

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1

2

3

Squamous cell carcinoma of the skin

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Colonic adenocarcinoma Colonic adenocarcinoma

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SarcomaSarcoma is malignant tumor arising from mesenchymal

tissue.

* Examples:

•Bone: osteosarcoma.

•Cartilage: chondrosarcoma.

•Fibrous tissue: fibrosarcoma.

•Fat: liposarcoma.

•Smooth muscle: leiomyosarcoma.

•Striated muscle: rhabdosarcoma.13

Tumor Grading (Differentiation) Tumor Grading (Differentiation) •Assessment of the degree of similarity between the tumor and its

parent tissue.

•Tumors may be:

• Well differentiated (grade I).

• Moderately differentiated (grade II).

• Poorly differentiated tumors (grade III).

• Undifferentiated tumors (grade IV).

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Well Differentiated Moderately differentiated

Poorly differentiated

B

C

Squamous cell

carcinoma

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Tumor StagingTumor Staging• Assessment of the degree of infiltration of the

tumor to the underlying tissue.

• Includes 3 parameters:

T (primary tumor): Tis, T1, T2, T3, T4

N (regional lymph nodes): N0, N1, N2, N3

M (metastasis): M0, M116

Spread of malignant tumorsSpread of malignant tumors

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I. Local (direct) spread:I. Local (direct) spread:

– The malignant cells infiltrates the surrounding

extracellular matrix in all directions and invade

the surrounding structures.

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II. Distant spread (metastasis):II. Distant spread (metastasis):

1. Lymphatic spread: 1. Lymphatic spread:

The tumor cells invade the walls of lymphatics and

pass with the lymph to the draining lymph nodes.

2. Blood spread:2. Blood spread:

The tumor cells invade the wall of blood vessels

and pass inside the circulation as tumor emboli to

reach distant organs.

3. Transcoelomic spread: 3. Transcoelomic spread: the tumor cells

invades the covering serous membranes and pass

between the visceral and parietal layers to a

distant organ e.g. from the gastric carcinoma to

both ovaries (Kruckenberg’s tumor)

4. Spread by implantation: 4. Spread by implantation: spread of tumor

cells between two opposing surfaces e.g. from

upper lip to lower lip.

Locally malignant tumorsLocally malignant tumors

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* Definition:

– Groups of malignant tumors that spread only locally

with no distant spread.

* Examples:

1. Basal cell carcinoma (skin)

2. Osteoclastoma (bone)

3. Adamantinoma (mandible).

4. Astrocytoma (brain).22

Tumor MarkersTumor Markers

* Def: Substances produced by the neoplastic cells and can be

demonstrated in cells, serum, or body fluids.

* Importance: They are used to:

1. Support diagnosis (they are not used as primary

modalities for diagnosis of cancer).

2. Assessment of cancer therapy.

3. Follow up.

* Examples: PSA for cancer prostate, CA-125 for cancer

ovary, CA-15-3 for cancer breast…..24

Immunohistochemical Immunohistochemical diagnosis of tumorsdiagnosis of tumors

• They detect the type tumors using their specific monoclonal

antibodies.

• Examples:

– Desmin for muscle tumors

– Cytokeratin (CK) and epithelial membrane antigen (EMA)

for epithelial tumors

– Leucocyte common antigen (LCA) for lymphoma.

– CD20 for B cell lymphoma.

– CD3 for T cell lymphoma.

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Positive CD20 in a case of B. cell lymphoma

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Causes of death in Causes of death in

Malignant tumorsMalignant tumors

1. Destruction of vital tissues such as brain, liver, kidney.

2. Malnutrition due to interference of food intake,

digestion and absorption.

3. Obstructive effects e.g. urinary tract obstruction.

4. Severe anemia.

5. Malignant cachexia: wasting, loss of weight and

muscular weakness with depressed immunity.

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