Lecture 8 - Neoplasms I Flashcards
what is benign neoplasia?
abnormal growth of cells which persists after intiating stimulus is removed
what is the appearance of a benign neoplasm?
rounded mass due to pushing growth
remains at site of origin
what is malignant neoplasia?
abnormal growth of cells which persists after initiating stimulus has been removed and invades and spreads to distant sites
what is the appearance of a maligant neoplasm?
irregular mass due to infiltrative growth edges
may spread to distant site formed secondary growth (metastasis)
what dna alterations must occur for neoplasia?
must cause alteration in cell growth and behaviour
change must not be lethal and passed onto daughter cells
series of around 7 genetic alterations
where do genetic alterations occur for neoplasia?
proto oncogenes or tumour suppressor genes
if a mutation permanently activates a proto oncogene so it becomes an oncogene or if a tumour suppressor gene is permanently inactivated, neoplasia will occur
what are the key differences in neoplastic cells?
self sufficient growth signals - HER2 gene amplification
resistance to antigrowth signals - CDKN2A gene deletion
grow indefinitely - telomerase gene activation
induce new blood vessels - activation of vegf expression
resistance to apoptosis - bcl2 gene translocation
invade and produce metastases - altered e-cadherin expression
what is the clonality of neoplasms?
monoclonal
cell population descended from common ancestral cell
what are the qualities of a benign tumour?
variation in size and shape minimal
low mitotic count - mitoses have normal form
retention of tissue specialisation - well differentiated
what are the qualities of a malignant tumour?
variation in size and shape minimal to marked
low to high mitotic count - mitoses may have abnormal forms
variable loss of tissue specialisation - well to poorly differentiated
what is carcinoma in situ?
all the features of malignant neoplasm in epithelium but no invasion through basement membrane
how are neoplasms names?
benign or malignant
tissue type
what is the suffix for benign epithelial neoplasms?
-oma
what is the suffix for malignant epithelial neoplasms?
-carcinoma
what is the name of a benign stratified squamous tumour?
squamous papilloma
what is the name of a benign transitional epithelial tumour?
transitional cell papilloma
what is the name of a benign glandular tumour?
adenoma
