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Tuesday, September 8, 2009


Tumors are classified on the basis of their location, microscopic appearance, and extent of spread. Of particular importance are the tumor's GRADE that is the degree of maturity or differentiation under the microscope and STAGE that is the extent of spread within the body. These two properties influence the prognosis that is the chances of successful treatment and survival and determine the specific treatment to be used.

When grading a tumor, the pathologist is concerned with the microscopic appearance of the tumor cells, specifically with their degree of maturation or differentiation. Often, four grades are used. Grade I tumors are very well differentiated, so that they closely resemble the normal parent tissue of their origin. Grade IV tumors are so undifferentiated or anaplastic that even recognition of the tumor's tissue of origin may be difficult. Grade II and III are intermediate in appearance, moderately or poorly differentiated, as opposed to well differentiated that is grade I and undifferentiated grade IV.

Grading is often of value in the prognosis of certain types of cancers, such as cancer of the urinary bladder and ovary and brain tumors such as astrocytomas. Patients with grade I tumors have a high survival rate, and patients with grades II, III, and IV tumors have a poorer survival rate. Grading is also used in evaluating cells obtained from body fluids in preventive screening tests, such as Papanicolaou's or Pap smears of the uterine cervix, tracheal secretions, or stomach secretions.

The staging of cancerous tumors is based on the extent of spread of the tumor rather than on its microscopic appearance. An example of a staging system is the TNM staging system. It has been applied to malignancies such as lung cancer, as well as many other tumors. T refers to the size and degree of local extension of the tumor. N refers to the number of regional lymph nodes that have been invaded by tumor. M refers to the presence or absence of metastases that is spreads to distant sites of the tumor cells. Subscripts are used to denote size and degree of involvement. For instance 0 indicates undetectable and 1, 2, 3, and 4-a progressive increase in size or involvement. A tumor may be described as T1, N2, M0 that is a small tumor with spread to regional nodes, but no distant metastases.



T0-No evidence of primary tumor

T IS-cancer in situ

T1, T2 T3 T4-Progressive increase in tumor size and involvement

TX-tumor cannot be assessed


N0-regional lymph nodes not demonstrably abnormal

N1, N2, N3, N4-increasing numbers or increasingly distant location of spread to regional lymph nodes.

Nx- regional lymph nodes cannot be assessed clinically.


M0- no evidence of metastasis.

M1, M2, M3, M4-Ascending degrees of distant metastasis

In the next lesson we will study about Cancer Treatment Methods and Its Administration Types. Okay.

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TYPES OF TUMORS AND THEIR ORIGINS:  1. Alveolar: Tumor cells outline prototypes bearing resemblance to tiny and microscopic pouches. They are normally brought into being in tumors of muscle, bone, fat, and cartilage.

2. Carcinoma in situ: This microscopic term of cancer refers to confined to a small area and tumor cells that have not marched into neighboring formations. Cervical cancer of possibly will start in on at the same time as carcinoma in situ.

3. Diffuse: Distribution in an even way all the way through the affected tissue. Malignant lymphomas may display diffuse attachment of lymph nodes.

4. Dysplastic: With reference to atypical development of cells. These tumors exhibit a exceedingly abnormal other than not obviously cancerous look. Dysplastic nevi such as moles of skin are the examples of this type.

5. Epidermoid: Similar to squamous epithelial cells. They are thin and plate-like. They are over and over again taking place in the respiratory tract.

6. Follicular: Appearing tiny and microscopic and gland like pouches. Thyroid gland is an case in point.

7. Nodular: Forming multiple parts of closely packed bunches of cells by way of gently populated areas stuck between.

8. Papillary: Bladder cancer possibly illustrated as papillary. They are forming tiny finger-like or nipple-like protuberances of cells.

9. Pleomorphic: They are composed or collected of a variety of type of cells. The examples for pleomorphic type cells is mixed-type tumors.

10. Scirrhous: Scirrhous means hard. They are tightly jam-packed tumors. They are untidy growths with rubbery tough tissue. They are frequently in breast or stomach cancers.

11. Undifferentiated: They are not deficient in microscopic formations having the characteristic of typical full-grown healthy cells.

In the next lesson we will learn about Grading and Staging of Cancer. Okay.

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