Pathology - large tubes Flashcards
whats a polyp
small growths of tissue in the colon
hsito characterization of polyps
flat
sessile
pedunculated
based on protrusion into colonic lumen
describe a hyperplastic polyp
non neoplastic
general smaller and in the rectosigmoid area
what are most common type of polyp
hyperplastic
smaller
rectosigmoid
non neoplastic
list the non neoplastic types of polyps
hamartomatous
hyperplastic
list the neoplastic types of polyps
adenomatous
serrated
tuular adenomatous polyp malig risk
lower than villous
villous adenomatous polyp maligi risk
higher than tubular
describe a hamartomatous poly
tissue of origin - frowths of normal colonic tissue with distorted architected
solitary lesions
no signi risk of mali transformation
non neoplastic
lsit two syndromes associated with hamartomatous polyps
peutz jegher
juvenile polyposis
list syndromes associated with adenomatous polys
FAP
gardner
turcot
BRAF mutations and polyps
serrated
describe serrated polyps
premalignant
CpG methylation phenotype pathway with microsatellite intability
saw tooth of crypts on biopsy
what is responsible for 20% of sporadic colorectal cancer
serrated poly CpG methylation phenotype pathway with microsatellite instability sawtooth crypts premaligi BRAF mutation
inheritance pattern of familial adenomatous polyposis
AD
APC gene on 5q
chromosome of FAP
chromosome 5q with APC
TWO HIT HYPOTHESIS
when do polyps start in FAP and who cares
start after puberty
100% progress to colorectal cancer unless resected
FAP osseous tumours/osteosarcoma soft tissue tumours/desmoid tumour hypertrophy of retinal pigment epithelium impacted/supernumerary teeth
gardner syndrome
describe gardner syndroem
AD supernumerary/impacted teeth hypertrophy of retinal pigment epithelium soft tissue tumour/desmoid tumor osseous tumors/osteosarcoma FAP
FAP
malignant CNS tumor - astrocytoma, medulloblastoma
Turcot syndrome
describe turcot syndrome
AR
FAP
malignant CNS tumour - astrocytoma, medulloblastoma
numerous hamartomas in the small bowel hyperpigmented buccal mucosa lips hands genitalia
peutz jegher
inheritance patter of peutz jegher
AD
describe peutz jegher
multiple hamartous polys mainly in small bowel
hyperpigmentation of lips, mucosa, hands, genitals
increased risk of colorectaol , breast, stomach, small bowe, pancreatic cancers
increased cancer risk with peutz jegher
colorectal stomach breast small bowel pancreatic
child less than five
hamartomatosu polyps in colong, stomach, small bowel
juvenile polyposis syndrome
describe juvenile polyposis syndrome
AD
child less than five
hamartomatous polyps in colon, stomach, small bowel
list the syndromes associated with colon poyls and their pattern fo inhertiance
FAP - AD Gardner - AD Turcot - AR Peutz jegher - AD Juvenile Polyposis - AD Lynch syndrome - AD
what is lynch syndrome
AD mutuation of DNA mismatch repair genes with subsequent microsatellite instability
increased risk fo what in juvenile polyposis syndrome
colorectal cancer
pJ: colorectal, breast, stomach, small bowel, pancreatic cancer increased risk
what portion fo the colon is always involved in lynch syndrome
the proximal colon
what type of cancer is lynch syndrome associated with
colorectal
breast
ovarian
skin
colorectal
breast
ovarian
skin
how do you identify lynch syndrome in families
3-2-1 rule
3 relative with Lynch syndrome-associated cancers (colorectal, breast, ovarian skin) across 2 generations, 1 that msut be diagnosed before 50 years old
when should you suspect thers some lynch syndrome going on.
breast/ovarian/colorectal/skin cancer in 3 family members in 2 generations with at least one of them diagnosed before 50 years old.
what is the second most common cause of cancer-related death in men and women
colorectal cancer
typical patient in colorectal cancer
> 50 years old
25% have familial history
risk factors for colorectal cancer
adenomatous polyp serrated polyp familial cancer syndromes IBD - UC tobacco use diset of processed meats with low fibre
low fibre
and processed meats - colorectal
diverticulosis
most common site fo colorectal cancer
rectosigmoid > ascending > descending @ FA
descending @ goljan
exophytic mass
iron deificiency anaemia
weight los
right sided colon cancer
colicky pain
infiltrating mass
obstruction
hematochezia
LS colon cancer
hematochezia
diverticulosis
LS colon cancer
angiodysplasia
apple core lesion
colon cancer
streptococcus bovis endocarditis
colon cancer
when should you be suspicious of colon cancer
old man with fe def aneamia
post meno women with fe def anaemia
describe screening for colon cancer
after 50 years old
flexible sigmoidoscopy, stool occult blood test (not as good)
what is good marker for monitoring reoccurrence but not screeing colon cancer
CEA
CEA
marker for watching recurrence of colon cancer, but not screeing
list order of gene events that underlie the pathogenesis of colorectal cancer
APC - KRAS - p53/DCC
how much of colorectal cancer is due to the microsatellite instability pathway
15
describe the microsatellite instability pathway and colorectal cancer
DNA mismatch repair gene mustsaions - mutatiosn accumulate but no definced morphologic corrleates
seen at Lynch syndrome and sporadic
describe the APC/beta-catenint correlation with the pathogenesis of colorectal cancer
associated with 85% of spiradics.
schromsoonaml sintailiton
normal colon – ? – colon at risk
loss of APC: decreased intercellular adhesion and increased proliferation
normal colon – colon at risk – ? – adenoma
KRAS mutation: unregulated intracellular signal transduction
normal colon – colon at risk – adenoma – ? – carcinoma
loss of tumour suppressor gene(s) p53 and DCC
increased tumorigenesis
gene associated with decreased intracellular adhesion and increased proliferation in CRC
loss fo APC
gene associated with unregulated intracellular signal transduction in CRC
loss of KRAS
gene associated with increase tumorigenesis in CRC
loss of tumor suppresses p53 or DCC
