Glossary
?Oncology: Oncology is the study of tumors
?Hyperplasia: increase in the number of cells of a tissue
?Tumor: Abnormal mass of tissue produced by progressive, unlimited, 
purposeless proliferation of cells.Another definition: development of secondary malignant implants 
away from the primary tumor.Characteristics of Benign and Malignant Neoplasm
Character Benign Malignant
Shape Capsulated Not capsulated
Size Usually smaller than malignant Rapid increase in size
Degree of 
differentiation
Well- differentiated Cell show variable loss of 
differentiation
Mode of growth Grows by expansion, does not 
infiltrate
Grows at the periphery, 
infiltrate and destroy the 
surrounding tissue
Rate of growth Generally slow Grow rapidly
Metastasis Absent Present
Recurrence Not recurrent Recurrent
Tissue destruction No tissue destruction Extensive tissue destruction
Effect Insignificant effect except in vital 
organ
Dangerous effect
Benign tumor complications
??Carcinogenesis: process of transforming normal cells into malignant cells
?Metastasis: spread of cancer cells from the primary tumor to distant 
sites
?Thrombocytopenia: decrease in the number of circulating platelets;
associated with the potential for bleeding
?Alopecia: hair loss
Classification of tumor
? This process occurs through four stages: 
initiation, promotion, progression and metastasis
1 - The initiation process involves carcinogens (factors that contribute 
the development of cancer such as chemicals, physical factors) that alter 
the genetic structure of DNA within cells.Dietary substances associated with an increased cancer risk include fats, 
alcohol, salt-cured or smoked meats and a high caloric dietary intake.Presence or absence of distant metastases
Staging of cancer (Clinical staging):
The clinical staging classification system determines the extent of the 
disease process of cancer by stages:
?2- During promotion, repeated exposure to carcinogens transforms the 
genetic information so that cells begin to produce mutant (malformed) 
cell population.Viruses: viruses play a significant role in weakening immunologic 
defenses against neoplasms e.g. papilloma virus, and hepatitis B virus.Abnormal chromosomal patterns have been associated with extra 
chromosomes, too few chromosomes, or translocated 
chromosomes.e.g. Leukemia, meningiomas.The risk for cancer increases with long-term ingestion of carcinogens or 
co-carcinogens or chronic absence of proactive substances in the diet.Hormonal Agents
Disturbances in hormonal balance either by the body's own 
(endogenous) hormone production or by administration of (exogenous)
hormones.Malignant: A tumor which always invades the surrounding tissues 
and give metastasis.Approximately 5% to 10% of cancers of adulthood and childhood 
display a familial predisposition.- E.g. Cancers of the breast, prostate, and uterus are thought to depend on 
endogenous hormonal levels for growth.Benign: not cancerous; benign tumors may grow but are unable to
spread to other areas
?Obstruction of a hollow organ: bronchial adenoma causing 
bronchus obstruction.Rupture of cyst neoplasm: cyst adenoma of ovary.Overall, the incidence of cancer is higher in 
men than in women and higher in industrialized sectors and nations.3- Progression: This stage is characterized by increased growth rate of 
the tumor, increased invasiveness.Obesity is associated with endometrial cancer and possibly
postmenopausal breast cancers.- Oral contraceptives and prolonged estrogen replacement therapy.Presence or absence of lymph node involvement and its extent
?Malignant change: adenoma of colon----adenocarcinoma.?????????2.?4.?5.6.8.?????