MOD 8.1 - Neoplasia 1 Flashcards
What is the definition of benign neoplasia?
The abnormal growth of cells that persists after the initiating stimulus has been removed
Describe the appearance of a benign neoplasia
- Rounded mass due to the pushing growth
- Remains at the site of origin
What is the definition of malignant neoplasia?
The abnormal growth of cells that persists after the initiating stimulus has been removed and invades and spreads to distant sites
Describe the appearance of a malignant neoplasia
- Irregular and has a ‘craggy’ shape due to infiltrative growth edge
- May spread to a distant site and form a secondary growth
What is an oncogene?
A proto-oncogene that has been permanently activated
What are the hallmarks of cancer?
- Self sufficient growth signals
- Resistance to anti growth signals
- Grow indefinitely
- Induce new blood vessels
- Resistance to apoptosis
- Invade and produce metastases
Give an example of a self sufficient growth signal. How is this significant?
- HER2 gene amplification (breast cancer)
- Promotes cell proliferation
- Opposes apoptosis
How can deletion of the CDKN2A gene lead to resistance to anti-growth signals?
Opposes apoptosis
What can happen to cause a cell to grow indefinitely?
- Activation of the telomerase gene
- Elongates telomeres on chromosomes = provides a selective growth advantage
How can cancer cells cause angiogenesis?
Activate expression of VEGF
What causes resistance to apoptosis in neoplastic cells?
- BCL2 gene translocation (lymphoma)
What can cause production of metastases after invasion?
Altered E-cadherin invasion
How are neoplasms monoclonal?
Descend from a common ancestral cell as a cell population
common ancestral cell = the one that was originally mutated so could grow uncontrollably
Describe a benign neoplasm
- Little variation in size and shape
- Low mitotic count, normally shaped
- Well differentiated i.e. look like host tissue
Describe a malignant neoplasm
- Variation in size and shape can be varied
- Can have a low to high mitotic count, potentially abnormally shaped
- Differentiation is varied from low to high
What is dysplasia?
Abnormal maturation cells within a tissue
How are neoplasms classified?
- Whether they are benign or malignant
- By tissue type i.e. epithelial, connective tissue, lymphoid/haematopoietic, germ cell
What would a benign neoplasm of stratified squamous epithelium be called?
- Squamous papilloma e.g. of the skin
- Any tumour with finger like projections
What would a benign neoplasm of transitional epithelium be called?
- Transitional cell papilloma
e. g. of the bladder mucosa
What would a benign neoplasm of glandular epithelium be called?
Adenoma e.g. adenomatous polyp of the colon
What would a malignant neoplasm of stratified squamous epithelium be called?
Squamous cell carcinoma
e.g. of the skin, larynx etc
What would a malignant neoplasm of transitional epithelium be called?
Transitional cell carcinoma
e.g. of the bladder/ureters
What would a malignant neoplasm of glandular epithelium be called?
Adenocarcinoma e.g. of the stomach
What is leiomyoma and leiomyosarcoma?
- Leiomyoma = benign neoplasm of smooth muscle
- Leiomyosarcoma = malignant neoplasm of smooth muscle
