Flashcards in Neoplasia Deck (70)
What is a neoplasm?
an abnormal growth of cells that persists after initial stimulation is removed
What is a malignant neoplasm?
What is a benign neoplasm?
- it invades surrounding tissues and has potential to grow to distant sites (a cancer)
- it remains localised and will not spread to other sites
What is a tumour
a clinically detectable lump or swelling
What is dysplasia?
a premalignant state where cells have disordered tissue organisation but not yet neoplastic- it is reversible (unlike neoplasms which are irreversible)
Give an example of a nonneoplastic tumour?
Is neoplasia reversible?
no never :(
Describe the microscopic appearance of a benign vs maligant tumour?
benign: grow in confined area, have a pushing but defined outer margin, well differentiated (look like parent tissue)
malignant: irregular outer margin and shape and may show areas of necrosis and ulceration (if on surface), can be very well or very poorly differentiated
Describe the microscopic appearance of cells with poor differentiation (do not resemble parent tissue)
- increasing nuclear size
- decreasing cytoplasmic space
- more mitotic figures (mercedes benz sign)
- irregular shapes and sizes (pleomorphism)
What is the difference in appearance and prognosis or high vs low grade cancers?
high grade= poorly differentiated and worse prognosis
low grade= good differentiation and better prognosis
can dysplasia be asessed by level of differentiation?
yes - CIN1 to CIN3
What genes need to be mutated for a neoplasm to arise?
- a tumor suppressor gene needs to be inactivated
- a proto- onco gene needs to be mutated to an oncogene (activated)
What is the difference between an initiator and a promotor?
initiator: substance that causes mutations - e.g.: smoking
promotor: substance that causes cell proliferation and so you get an expanded population of cells
How does a cancer arise/progress over time?
What 4 classes of regulatory genes are affected by these mutations?
- Stepwise accumulation of complimentary mutations over time.
1) Proto-oncogenes - mutated to oncogenes and encode oncoproteins which promote cell growth in absence of growth promoting signals (gain of function mutations)
2) Tumour supressor genes - normally stop cell proliferation, mutations required to both alleles to cause loss of function (failure of growth inhibition)
3) Apoptosis regulating genes - may lead to enhanced survival of cells
4) DNA repair genes - loss of function mutations, inability to recognise and repair non-lethal genetic damage.
What features of a neoplasm does the new naming system take account of?
origin, benign or malignant, type of tissue formed and morphology
What tissue is affected if the prefix is:
- smooth muscle
- fibrous tissue
- glial cells
- nerve sheaths
What is the suffix for a benign neoplasm?
What is the name for a benign neoplasm of epethilia?
What is an adenoma?
benign neoplasm of a gland
What is the name for a malignant epithilal neoplasm?
What is the name for a malignant neoplasm of a gland?
when is the suffix '-sarcoma' used?
for a malignancy of connective tissue (chondrosarcoma, fibrosarcoma)
What is the difference between a leukaemia and a lymphoma?
leukaemia is malignancy of blood forming cells in bone marrow
lymphoma is malignancy of lymphocytes, mainly affecting lymph nodes
What is a myeloma?
malignancy of plasma cells
Where do germ line neoplasms arise?
from pluripotent cells of testis or ovaries
What is a blastoma?
a malignant neoplasm of immature precursor cells, usually occurring in children
What is a burkitt lymphoma?
- B cell lymphoma associated with EBV and malaria, most common in africa
What is a ewings sarcoma?
malignant tumour of bone, that usually presents in childhood/ adolescence
What is hodgkins lymphoma?
a malignant lyphocyte neoplasm characterised by presence of reed- sternberg cells. It is less common and often less aggressive than non hodgkins lymphoma
What is kaposi's sarcoma?
a malignant neoplasm derived from vascular endothilium, commonly associated with AIDS and herpes virus 8- presents with red patches