Neoplasia 1 8-6-15 Flashcards
What does neoplasia mean?
new growth
- disorder of cell growth
- triggered by series of acquired mutations of single cell and it clones
- monoclonal, autonomous, irreversible
What is a tumor?
abnormal growth of tissue
WHat is benign vs malignant?
benign- remain localized, do not metastasize
malignant- invade, destroy, and metastasize
What is cancer?
generic term for malignant neoplasm
THe two basic components of all tumors are parenchyma and stroma, describe parenchyma and stroma
Parenchyma
- neoplastic cells
- determine biological behavior
- source for the name of neoplasm
- neuroectodermal, epithelial, or mesenchymal in origin
Stroma
- connective tissue, blood vessels, immune system cells
- support growth and spread of neoplasm
How are tumors classified? What is oma vs. sarcoma
according to their cell of origin
oma=benign
sarcoma=malignanat
What is a mixed tumors derived from 1 germ layer?
- single neoplastic clone capable of divergent differentiation
- derived from 1 germ cell
- more than 1 neoplastic cell type
Example: Salivary Gland
-Clone capable of epithelial and myoepithelial differentiation
-Pleomorphic adenoma-neoplastic epithelial cells scattered in neoplastic myxoid stroma
What are teratomas?
-rare tumors contain cells from more than one germ layer
What is a mixed tumor derived from more than 1 germ layer?
totipotent germ cells differentiate into any cell types found in human body
-neoplasms originate in gonads, abnormal midline embryonic rests
What is the cell morphology, rate of growth, spread of tumor for a benign tumor?
Morphology -Well-differentiated(resemble normal tissue compartment) to dysplastic Rate of Growth -Grow more slowly Spread of Tumor -Most encapsulated and stay localized
What is the cell morphology, rate of growth, spread of tumor for a malignant tumor?
Morphology
- well differentiated to very de -differentiated (anaplastic)
- pleomorphic (variation in nuclear shape and size)
- Abnormal nuclear morphology (high N/C ratio, hyperchromatic, prominent nucleoli)
- Mitosis
Rate of Growth
- Highly variable and unpredictable
- Usually varies with degree of differentiation
Spread of Tumor
- Infiltrate and destroy locally
- ability to metastasize
What do well-differentiated squamous cell carcinomas of the skin look like?
-tumor cells strikingly similar to normal squamous epithelial cells with intracellular bridges and nest of keratin (keratin pearls)
What is dysplasia?
disordered growth
- principally found in epithelium
- mutations leading to cytological and architectural changes of
- may be a PRECURSOR to malignant transformation
- mild to moderate dysplasias may regress (ie reversible)-particularly if inciting causes are removed
What is squamous carcinoma in-situ?
entire thickness of epithelium is replaced by atypical dysplastic cells
- no orderly differentiation of squamous cells
- basement membrane is intact and there is no tumor in the subepithelial stroma
Where does dysplasia often occur?
metaplastic epithelium
EX
-squamous cell carcinoma of the uterine cervix
-squamous cell carcinoma of the lung
How does metastasis occur?
- seeding within natural body cavities
- ovarian carcinomas seed peritoneal cavities - lymphatic spread
- more typical of carcinomas - hematogenous spread
- more typical of sarcomas
Why does cancer incidence vary with geography?
exposure to different environmental carcinogens
What are some proposed mechanisms to why obesity is associated with cancer?
- elevated insulin levels
- increased estrogens
- decreased adiponectin
- proinflammatory state
coal products, tar and mineral oils lead to …
aromatic amines and azo dyes in dye and rubber industry lead to…
asbestos exposure in construction and ship building lead to…
lung cancer
bladder
lung
Most cancers occur in greater 55 year olds, what is the most common cancer?
- carcinomas
- likely increased incidence of somatic mutations
- decline in immune competence with age
Cancer accounts for greater than 10% of deaths in children
- CNS neoplasms most common
- also theres leukemias
What are two autosomal dominant cancer syndromes?
- familial adenomatous polyps of colon: nearly 100 develop colon cancer
- familial retinoblastoma
- 100,000 times risk of cancer than in general population
What is a type of recessive syndrome of defective DNA repair that has the tendency to lead to cancer?
-xeroderma pigmentosum
Familiar cancers of uncertain inheritance have?
unclear pattern of inheritance and evident familial clustering
If you have chronic inflammation particularly T-cell deficiencies, is this a acquired predisposing condition?
yes
