park-neoplasia Flashcards
neoplasia
-dysregulated cell proliferation
-abnormal growth of cells or tissue
What are the two types of neoplasia?
malignant tumors (cancers)
benign tumors
Malignant tumors
-large
-poorly demarcated
-rapidly growing with hemorrhage and necrosis
-locally invasive
-metastatic
-poorly differentiated
benign tumors
-small
-well demarcated
-slow growing
-noninvasive
-non metastatic
- well differentiated
Naming of benign tumors
-adding the suffix -oma to the parenchymal tissue type
-ademona (glands), osteoma (bones), hemangioma (blood vessels), leiomyoma (smooth muscle), neuroma (neurons), glioma (glial cells)
Naming malignant tumors
-carcinoma
-sarcoma
-leukemia
-blastoma
carcinoma
-malignant tumor of epithelial tissue origin
-adenocarcinoma
sarcoma
-malignant tumor oc connective, muscle, endothelial tissues
-osteosarcoma, leiomyosarcoma, hemangiosarcoma
leukemia
-malignant tumor of blood cells
blastoma
-malignant tumor of precursor cells
-neuroblastoma, glioblastoma, retinoblasta
What are characteristics of cancer cells
-loss of cell differentiation
-genetic instability
-growth factor independence
-loss of cell density-dependent inhibition
-anchorage independence
-faulty cell-to-cell communication
-unlimited life span
-antigen expression
-abnormal production of proteins, hormones, etc
-cytoskeletal changes
loss of cell differentiation (anaplasia)
-resemblance to undifferentiated or embryonic cells
genetic instability
-aneuploidy (loss of gain of chromosomes)
-intrachromosomal instability (insertions, deletions, and amplifications of genes)
-micro satellite instability (short, repetitive sequences of DNA)
-point muations
growth factor independence
proliferation even in the absence of growth factors
loss of cell density-dependent inhibition
-lack of contact inhibition
-rampant growth without regard for adjacent tissue
-necessary fro invasion
anchorage independence
-cancer cells frequently remain viable and multiply without normal attachments to other cells and the extracellular matrix
-critical for metastasis
faulty cell-to-cell communication
formation of intracellular connections and responsiveness to membrane-derived signals are frequently interfered in cancer cells
unlimited life span
cancer cells can divide unlimited number of times
antigen expression
-cancer cells express many cell surface molecules or antigens that are immunologically identified as foreign (tumor antigens)
-ex. fetal proteins that are not expressed by the comparable cells in adult
-tumor antigen may be clinically useful as cancer biomarkers
abnormal production of proteins, hormones, etc
-cancer cells secrete degradative enzymes that enable invasion and metastatic spread
-cancer cells may synthesize hormones that promote their own growth (ex estrogen production by breast cancer)
-cancer cells may produce and secret procoagulant substances that affect clotting mechanisms
cytoskeletal changes
-changes in intermediate filament, actin filaments, and microtubules
-abnormal cell morphology
-facilitate invasion and metastasis
grading
-determined by microscopic examination of tumor cell morphology (histologic analyses)
-samples for these analyses can be obtained by excision or biopsy, fine needle aspirations, or cytologic (pap) smears
-largely qualitative in nature
-based on the differentiation state and the number of mitoses of the tumor
list the different grades
-grade X (grade cannot be assessed/ undetermined grade)
-grade I (well differentiated/ low grade)
-grade II (moderately differentiated/ intermediate grade)
-grade III (poorly/ high grade)
-grade IV (undifferentiated/ high grade)
two major classes of genes
-oncogenes- genes that encode the proteins that promote cancer
-tumor suppressor genes- genes that encode proteins that inhibit cancer