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Weeks 6 and 7 Neoplasia Dr.İ.Taci Cangül Bursa-2008.

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Presentation on theme: "Weeks 6 and 7 Neoplasia Dr.İ.Taci Cangül Bursa-2008."— Presentation transcript:

1 Weeks 6 and 7 Neoplasia Dr.İ.Taci Cangül Bursa-2008

2 Overview Neoplasia: new growth Neoplasm: mass of cells that composes the new growth Growth disturbances in which the regulatory mechanisms of cell contact inhibition, differentiation, and mitosis are defective Hyperplasia, metaplasia, and dysplasia

3 Definitions-I Oncology: study of or science of neoplastic growth Neoplasia: new growth Neoplasm: mass of cells composing the new growth Tumor: any swelling (currently used almost exclusively to refer to a neoplastic growth)

4 Definitions-II Cancer: common term used for all malignant neoplasms Benign neoplasm: a neoplasm that tends to grow slowly, is well differentiated, does not metastasize, and is usually non-life threatening Malignant neoplasm: a neoplasm that tends to grow rapidly, is poorly differentiated, often metastasizes, and frequently causes death of the host

5 Definitions-III Metastasis: transfer of disease manifestations from one organ to another. It is used mainly to refer to the secondary growth of a malignant neoplasm in an organ or site remote from the primary site Differentiation: process where by one form, typically the immature, develops into another, usually the mature. As it relates to cells, this generally involves the development of immature cells into mature ones


7 Definitions-IV Anaplasia: tendency of a neoplasm to be composed of less differentiated/mature cells

8 Nomenclature Benign: -oma (adenoma, fibroma) Malignant: –carcinoma (epithelial origin) (adenocarcinoma) –sarcoma (mesenchymal origin) (fibrosarcoma)

9 Differentiation of Benign and Malignant Neoplasms Degree of cellular differentiation or cellular anaplasia Rate of growth Mode of growth and spread Anaplasia and metastasis are the "hallmarks" of malignancy.


11 Features of Anaplasia 1. Pleomorphism (variation in size and shape of cells and nuclei) 2. Hyperchromatism (nuclei contain abundance of dark-staining chromatin) 3. Enlarged nucleoli 4. Increased mitosis with abnormal mitotic figures 5. Formation of tumor giant cells (in some instances)

12 Rate of Growth In general: –Benign tumors: slowly –Malignant tumors: rapidly, sometimes at an erratic pace, eventually to spread and kill the host. Mitosis


14 Mode of Growth and Spread Encapsulation Implantation Metastasis


16 Encapsulation Characteristic of benign neoplasms Lack of a capsule does not make a neoplasm malignant






22 Metastasis Spread of neoplastic cells from one part of the body to another Hematogenous Lymphogenous

23 Implantation Transfer of neoplastic cells from one serous or mucous surface to another by direct contact Significant potential hazard during cancer surgery



26 Causes of Neoplasia Oncogenic viruses Carcinogenic chemicals Radiation Other agents

27 Oncogenic Viruses RNA viruses: retroviruses, oncornaviruses, leukoviruses DNA viruses: papova viruses, adenoviruses, herpesviruses

28 Carcinogenic Chemicals Dose-dependent, additive and irreversible Lag period Changes transmitted to daughter cells Enhancement by cellular proliferation Diversity in antigenic diversity as well as a diversity of phenotypes in terms of histologic patterns, degree of differentiation, cell surface properties and other attributes of neoplastic transformation

29 Predisposition to Neoplasia Heredity Age Gender Pigmentation Hormones Chronic Irritation Parasites

30 General Characteristics of Neoplasia Morphology: –Benign neoplasms tend to extend above the surface of the skin or the organ –Malignant neoplasms tend to be very irregular in shape and to infiltrate the underlying tissue Metabolism: –High rates of both aerobic and anaerobic glycolysis



33 Restraint of Neoplasms Endocrine dependent neoplasms Nutrition Chemotherapy Neoplasm immunity


35 Clinical Effects of Neoplasia-I Atrophy of surrounding cells Obstruction of the lumen or organs Destruction of blood or lymph supply Destruction of nerve supply Bacterial invasion of the neoplasm

36 Clinical Effects of Neoplasia-II Emaciation Anemia Excessive production of hormones Death of the individual Spontaneous regression and recovery


38 Diagnosis of Neoplasia Biopsy Exfoliative cytology Radiology Chemical analysis




42 Treatment of Neoplasia Surgery X-rays Radium and other radioactive materials Endocrine products Chemicals Immunotherapy

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