8 - Neoplasia and Growth Disturbances (Exam 2) Flashcards
What are polyps?
Any abnormal protrusion from a mucosal surface OR
a mass that projects above a mucosal surface to form a visible structure
What are 4 examples of mucosal surfaces where polyps can occur?
- Oral cavity
- GI tract
- Respiratory tract
- Genitourinary tract
What are 3 reasons for polyp occurrence?
- Chronic inflammation
- Hyperplasia
- Neoplasia
What is leukoplakia?
Opaque, white, hyperplastic lesions found on mucous membranes, often pre-cancerous, that have a high potential of transformation to malignant cells
What are 3 common locations of leukoplakia?
- Oral cavity
- Respiratory tract
- Cervix
What is a neoplasia?
New growth
What are 3 origins of all neoplasms?
- Loss of responsiveness to normal growth control
- Excess of stimulation leading to net growth
- Deficiency of inhibition leading to net growth
What is a tumor?
A swelling
What are 5 causes of tumors?
- Edema
- Hemorrhage
- Inflammation
- Hyperplasia
- Neoplasia
What is oncology?
The study of tumors
What 2 basic components do all neoplasia have?
- Parenchyma (bulk of the tumor)
2. Supporting stroma (connective tissue/blood vessels)
What are the types of neoplasia based on?
Cell type and
Degree of malignancy
How are benign neoplasms names?
Prefix - cell line
Suffix - oma
How are malignant neoplasms named?
Prefix - cell line
Suffix - carcinoma if epithelial, sarcoma if CT or muscle
What are 4 exceptions to the neoplasia naming system?
- Hematoma - Collection of blood exudates
- Lymphoma - malignant
- Glioma - malignant
- Blastoma - malignant (neuroblastoma, retinoblastoma)
What are 7 common characteristics of benign neoplasms?
- Slow growth rate
- Normal mitosis for the type of cell it is
- No signs of metastasis
- Normally single cell type, two types not uncommon
- Normally well differentiated
- Localized, do not spread
- May cause compression or secrete hormones
What is a more common name for malignant neoplasia?
Cancer
What 5 things does the word malignant imply?
- Invasion
- Infiltration
- Spread
- Major compression
- Tissue destruction
What are 6 common characteristics of malignant neoplasms?
- Growth rate variable from slow to rapid
- Atypical mitosis
- Variable degree of metastasis
- Single cell type, unless germ cells
- Differentiation correlates with growth rate
- Spread at some point in time
What are the 4 stages of life for a neoplasm?
- Initiation - transformation
- Clonal expansion
- Local invasion
- Metastasis
During which stage of life does a cell or group of cells appear different from normal?
Initiation - transformation stage
What phase is the resting state of the cell?
G0 phase
What 4 phases make up the active phase of the cell?
- G1
- S
- G2
- M
What occurs in the G1 phase?
Pre-DNA synthesis
What occurs in the S phase?
DNA synthesis
What occurs in the G2 phase?
Pre-mitosis
What occurs in the M phase?
Mitosis and cytokinesis
What 5 things may recruitment be associated with?
- Deficiency of growth inhibitors
- Excess of growth stimulators
- Age
- Heredity
- Environmental growth factors
What are 3 major types of genes?
- Oncogenes
- Suppressor genes
- Protooncogenes
What 2 things can oncogenes initiate?
- Formation of excess amounts of growth factor
2. Formation of abnormal growth factors
If suppressor genes are inactivated, what will be allowed to happen?
Unlimited activity of growth factor
What are protooncogenes?
Potential oncogenes that are normally inactive (but may be activated)
In what age group does acute leukemia primarily occur?
The young
In what age group does chronic leukemia primarily occur?
The old
What do pre and post-menopausal neoplasms differ based on?
Hormonal stimulation
What are 2 examples of neoplasms initiated during embryonic development?
- Neuro-retinoblastoma
2. Rhabdomyosarcoma
What percentage of individuals will develop some form of cancer?
25%
Is heredity a cause of cancer?
Only a few types
What are 3 types of cancer that have been shown to be hereditary?
- Childhood retinoblastoma
- Multiple polyposis coli (colon)
- Mammary adenocarcinoma (breast)
What types of genes are involved with childhood retinoblastoma?
Autosomal dominant gene
Suppressor gene
What type of gene is involved with multiple polyposis coli?
Autosomal dominant gene
What percent of people who have multiple polyposis coli will have carcinoma of the colon by age 50?
100 %
What are 3 major types of carcinogenic environmental factors?
- Chemicals
- Radiant energy
- Oncogenic viruses
What are 5 examples of chemical carcinogens?
- Organic solvents (toluene, carbon tetrachloride)
- Alkylating agents
- Antiviral drugs
- Procarcinogens (aromatic amines and amides)
- Natural plant and microbial products and toxins
What are 2 examples of the mode of action of chemical carcinogens?
- Inducement of mutations that affect oncogenes and/or suppressor genes
- Associated with ability to suppress “natural killer cells”
What are 4 possible sources of radiant energy?
- UV radiation (sunlight)
- X-rays
- Nuclear fission
- Radioactive isotopes
What is a possible malignancy resulting from UV radiation?
Skin cancer
What are some possible malignancies resulting from X-rays?
Leukemia Thyroid cancer Breast carcinoma Colon carcinoma Pulmonary carcinoma Osteosarcoma
What are some possible malignancies resulting from nuclear fission?
Leukemia Thyroid cancer Breast carcinoma Colon carcinoma Pulmonary carcinoma
What is a possible malignancy resulting from radioactive isotopes and who may be at risk?
Pulmonary carcinoma
Miners of radioactive elements
What are 2 examples of the mode of action of radiant energy damage?
- Associated with point mutations on genes
2. May result from chromosomal breakage and/or translocation of chromosomes during cell division
What are 2 things that radiant energy damage results in?
- Formation of oncogenes
2. Loss or damage of suppressor genes
What are 3 types of oncogene viruses and what do they lead to?
- Human T-cell leukemia virus (leukemia)
- Human papilloma virus (cervical cancer)
- Hepatitis viruses (hepatoadenocarcinoma)
What are 4 examples of foods that may cause exogenous carcinomas?
- Alfatoxins (related to certain molds)
- Food additives
- Pesticides
- Artificial sweeteners
Lack of what nutrient may lead to increased time of fecal matter in the colon and therefore a greater chance of exposure to carcinogens?
Fiber
What stage of neoplasm life do benign neoplasms not pass?
Clonal expansion
What does the proliferation rate of neoplastic cells depend on?
Doubling time of cells
- fast for malignant neoplasms
- slow for benign neoplasms
What enzyme do neoplastic cells have that helps to maintain telomere length?
Telomerase
What is the growth fraction indicative of?
Cells in the active proliferative stage
What are the 4 stages of development with neoplasms?
- Actively proliferating and clonogenic
- Non-proliferating but still clonogenic
- Non-proliferating and not clonogenic
- Undergoing lysis and reabsorption (seen in malignancy, when cells outgrow blood supply)
What size can tumors not develop beyond without neovascularization?
1-2 mm
Is angiogenesis mandatory for normal tumor formation?
Yes
Which stage of neoplastic life is the beginning of metastasis?
Local invasion
Extracellular matrix is breached
With what types of neoplasms is metastasis seen?
Malignant neoplasms only
What are the 3 pathways from which metastasis may occur?
- Seeding within body cavities
- Lymphatic spread
- Hematogenous spread
Where does hematogenous spread occur?
Usually in the veins as opposed to the arteries
What are the primary targets of hematogenous spread?
Capillary network areas
Lungs
Liver
Brain
