Bowel Path IV Flashcards
lymphoid polyp
non-neoplastic
adenoma
adenomatous polyp
neoplastic
most common adenoma
tubular adenoma - small and pedunculated
greater than 4cm diameter polyp
40% chance contain foci of cancer
epithelial dysplasia
in adenoma
is pre-malignant
tubular adenoma
neoplastic
pedunculated
velvety surface
have small round tubular glands
villous adenomas
larger and sessile - covered in villi
sessile serrated adenomas
like hyperplastic polyp
-but more common in right colon
hyperplastic polyp vs. sessile serrated adenoma
serrated architecture throughout in a sessile serrated adenoma
-also in right colon
only on surface of hyperplastic polyp
malignant risk
larger polyp
more epithelial dysplasia
villous > tubular
APC/WNT pathway
typical adenocarcinoma of colon
both familial and sporadic colon cancer
FAP
100% patients get colon cancer if don’t do anything hundreds to thousands of polyps
microsatellite instability
mutation of MSH2 or MLH1 gene result in loss of enzymes in repair of damaged DNA - accumulation of microsatellite repeats
- mutation in TGF-beta receptor
- BAX genes
- BRAF gene
seen with HNPCC
-MLH1 and MSH2
familial adenomatous polyposis
auto dominant
-500-2500 colon polyps
colon cancer in 100% by age 30
most have APC gene defect, some MYH
HNPCC
lynch syndrome
hereditary non-polyposis colorectal cancer
auto dom
colon ca at young age
right sided and mucinous
microsatellite instability due to mismatch repair gene defect
CHRPE
congeintal hyperplasia of retinal pigmented epithelium
newborn with FAP
1st indication of mutation
colon carcinoma
common
clinical sx - mild abdominal discomfort, fatigue, weight loss, anemia
elevated CEA
with strep bovis
majority left sided
diet, smoking, alcohol, adenoma hx, black, older age
iron deficiency anemia in older man or postmenopausal woman
GI cancer - unless proven otherwise
path of colon carcinoma
requires multiple hits
two pathways:
- classic -APC/beta catenin - majority
- microsatellite instability - DNA mismatch repair defect
microsatellite instability
DNA mismatch repair defect
in colon carcinoma
majority of colorectal neoplasias
sporadic 97%
familial 3%
napkin ring lesion
colorectal carcinoma
typically left sided
aka apple core lesion
regional lymph nodes of colon
in pericolonic fat
VEGF
induces vessels to tumor
hard node
cancer
colon carcinoma mets
lymph node, lung, liver
dukes criteria
for level of invasion of colorectal carcinoma
T-IS
in situ
T1
no muscularis
T3
to serosa
T4
to adjacent organ
T2
to muscularis
staging of colorectal carcinoma
T - tumor
N - nodes
M - mets
stage 1 and 2
no nodes, no mets
stage 3
nodes, no mets
stage 4
nodes and mets
screening for colorectal cancer
after age 50yo - colonoscopy every 10 years is gold standard
carcinoid tumor of small bowel
neuroendocrine origin
mostly distal in ileum
malignant
adenomas and adenocarcinomas of small bowel
mostly in duodenum - proximal
carcinoid tumor
well differentiated neuroendocrine carcinoma
foregut - rarely met
midgut - often met and aggresive
hindgut - incidental finding
secrete - serotonin**
severe episodic skin flushing, diarrhea, cramping, asthma, tricuspid valve insufficiency
carcinoid tumor
serotonin secretion
carcinoid tumor
salt and pepper pattern of tumor
carcinoid tumor
cytoplasmic dense neurosecretory granules
vermiform appendix
in cecum - lymphoid rich
no known function
blind end tube attached to cecum
acute appendicitis
peri-umbilical pain - localizes to RLQ - mcburney
N/V
abdominal tenderness, rebound
mild fever
leukocytosis
exploratory laparoscopy outweighs risk of appendix perforation
fecalith
hard stool in appendix
-can cause inflammation and appendicitis
tumors of appendix
mostly carcinoid
mucocele and pseudomyxoma pertonei
tumor of appendix secreting mucin to abdominal cavity
jelly belly
jelly belly
mucin in abdominal cavity
-with tumor of appendix
mucocele and pseudomyxoma peritonei
peritonitis
bile leak, pancreatic enzymes, foreign material, endometriosis, ruptured dermoid cyst, perforation
bacterial peritonitis
may be fatal or heal with adhesions
e. coli, pneumococcus
mesothelioma
malignant tumor of peritoneal cavity
with asbestos exposure
tumors in peritoneal cavity
majority secondary to mets - ovary, pancreas, GI
