Test 3 Flashcards
localized and amenable to surgical removal; patient usually survives
benign
invasive tumor capable of destroying structures and spread to distant sites (metastasis); may result in early death of the patient
malignant
benign tumor of fibrous tissue
fibroma
benign tumor of fat
lipoma
benign glandular tumor
adenoma
benign cartilaginous tumor
chondroma
benign squamous epithelial tumor
papilloma
What are sarcomas?
malignant tumors of mesenchymal derivation (connective tissues); Examples– fibrosarcoma, chondrosarcoma
What are carcinomas?
malignant tumors of epithelial derivation; 80% of all malignancies
examples— adenocarcinoma, squamous cell carcinoma
tumors with more than one neoplastic cell type (epithelial and mesenchymal)
mixed tumors
tumors with more than one neoplastic cell type and derived form more than one germ layer
compound tumors
Which type of neoplasms are said to be differentiated (resemble tissue of origin)?
benign neoplasms
How can benign tumors cause problems?
1) secreting a substance (hormone, etc) in abundance
2) compressing vital organs
3) a few benign tumors may transform into malignant tumors
What are the hallmarks of malignancy?
invasion and metastases
What are the 2 steps involved in chemical carcinogenesis?
Tumor initiation and tumor promotion
INITIATION ALONE IS NOT SUFFICIENT FOR TUMOR FORMATION
Describe tumor initiation (In regards to chemical carcinogenesis).
an IRREVERSIBLE process involving the single application of a chemical or physical agent
Describe tumor promotion (In regards to chemical carcinogenesis).
a reversible process involving multiple applications of a promoting agent. Promoters cause cell proliferation.
Promoters are not carcinogenic.
Describe direct acting carcinogens.
They do not require metabolic activation to have their effect
Describe indirect acting carcinogens (procarcinogens)
require metabolism to produce ultimate carcinogen; generally performed by the cyt P-450 mono-oxygenate system
What is the primary target of chemical carcinogens?
DNA
How is ionizing radiation carcinogenic?
it causes strand breaks in the DNA
How is UV radiation carcinogenic?
it causes the formation of pyrimidine dimers in DNA; these are very hard to repair
Which UV rays are given credit for the observed increases in skin cancer?
UVB (280-320nm)
What are the common high risk strains of HPV that cause cancer?
Types 16, 18, and 31