cellular pathology of cancer Flashcards
define metaplasia *
a REVERSIBLE change in which one adult cell type (usually epithelial) is replaced by another adult cell type
adaptive - cells sensitive to stress eg acid are replaced by cells that can cope
physiological example of metaplasia
cervix in puberty - go from columnar to squamous epithelium when exposed to acid of vagina
pathological example of metaplasia
barret’s oesophagus - squamous epithelium to columnar - because of change in pH - exposure to acid from acid reflux
respiratory columnar ciliated epithelium changes to squamous
definition of dysplasia *
an abnormal pattern of growth in which some of the cellular, architectural, molecular and genetic features are present that associate with cancer
but not invasive
pre-invasive stage with intact basement membrane
it is the step between normal cells and cancer
reversible
what can be seen in dysplasia *
more mitosis and abnormal mitosis
big nuclei
loss of architectural orientation - lose sequence from basement cells to maturing to keratinisation ie cells arent maturing in the normal way
loss of uniformity of individual cells
hyperchromatic nuclei - dark becasue contain more DNA
mitotic figures - abundant, abnormal and in places that they shouldnt be found
increased nuclear:cytoplasmic ratio - increase in size of nuclei but the cells dont get bigger - nuclei take up a greater proportion of the cell
enlarged nuclei
where is dysplasia common
cervix - HPV infection
bronchus - smoking
colon - ulcerative colitis
larynx - smoking
stomach - pernicious anaemia (chronic inflamm process)
oesophagus - acid reflux (have metaplasia, that progresses to dysplasia, which progressses to adenocarcinoma)
what is the difference between low and high grade dysplasia *
low - risk of progression is less, more likely ti be reversible
high - higher risk of invasion, closer to develop invasive cancer, nucleocytoplasmic ratio high so darker
what is a neoplasia, tumour or malignacy *
an abnormal, autonomous proliferation of cells, unresponsive to normal growth contriol mechanisms and persists even when whatever started the growth mechanism has stopped
(from yr1 - tumour is any mass forming lesion)
what are characteristics of benign tumour *
DO NOT INVADE/METASTISE - do not invade bv or spread - this is the functional characteristic
encapsulated - in fibrous capsule, easy to remove
usually well differentiated - look like tissue from where they come from
slowly growing - low mitotic rates
normal mitosess
(these are ways recognise benign tumours but dioesnt diagnose them as benign except for the 1st one)
benefit of tumour being benign *
easier to treat
treatment is 100% effective - no chance that it ahs spread
how would you test if a tumour had invaded tissue *
eg on chest - if you can move it, it is not attached to the skin/pec major =benign
when can a benign tumour be fatal *
in dangerous place eg meninges (if block frow between ventricles = hydrocephaly/increased intracranial pressure = death), or pit (press on important things like optic canal, also secrete hormones)
secretes something dangerous eg insulinoma (tumour of B cells)
gets infected eg bladder
ruptures eg liver adenoma - bleeds into the peritoneal cavity
bleeds - stomach (if presses on an artery which bleeds)
torts (twisted) - block blood supply - infarction eg ovarian cyst
characteristics of a mialignat tumour *
invades surrounding tissues
spreads to distant sites - via bv, nerve and lymphatics (if catch early might not have spread, doesnt mean that it is not malignant) prognosis depends on how far spread/invaded
no capsule
well to poorlyu differentiated
rapidly growing
abnormal mitoses
define metastasis *
a discontinuous growing colony of tumour cells, at distance from the primary cancer
in these cases local treatment is not enough
what determines metastasis *
lymphatic and vascular drainage of the site
lymph node involvement has a worse prognosis
eg colon - Dukes A = 90% - only in bowel wall, Dukes C = 30% - in lymph nodes
which lymph nodes to the testicles drain to
aortic
which nodes does the breast drain to
lateral - axillary
medial - internal mammary nodes
what is nuclear polymorphism *
when nuclei all look different from each other