Peritoneum & Large Intestine Colorectal Cancer Syndromes Flashcards
What are the common causes of peritonitis?
Why is it a concerning diagnosis?
- Caused
- anythign that irritates the peritoneum
- bacterial infection (perforation some GI organ), chemical irritant (bile), talc (foreign body), ongoing inflammatory process
- all we see histologically is inflammatory cells
- Concerning
- can die from it b/c can get septic
Why type of tumors grow on the peritoneum?
- most are malignant
- primary tumors are uncommon
- mesothelioma
- associated with asbestos exposure
- mesothelioma
- secondary tumors are common
- direct spread or metastic seeding from abdominal or pelvic organs
What is shown by these two images of primary peritoneal mesothelioma?
What are the most common tumors producign diffuse serosal implants?
What is produced by mucinous carcinomas?
- ovarian carcinoma
- panreatic adenocarcinoma
- mucinous mcarcinmoas may produce pseudomyxoma peritonei
- 95% from appendiceal mucinous tumors
What part of the GI tract is shown?
the colon should look like a rack of test tubes
- test tubes are glands
- straight, evenly sized
- reach the base of the “rack”
- Rack is muscularis mucosae
- lumen of glands should be smoolth
What is Hirschprung disease?
- Congenital aganglionic megacolon
- failure of neural crest cell migration
- premature ganglion cell death
- 10% associated w/ Down syndrome
- Always include rectum, but can also include colon
- presentation
- failure to pass meconium, constipation, obstruction
- Can be acquired from chagas
- The bulgy part is actually the “normal” part of the bowel, whereas the abnormal (aganglionic) will be clamped down
What is the etiological cause of antibiotic-associated colitis?
- Clostridium difficile is most common cause
- look for it by seaching for C. diff Toxin A
- associated with antibiotic use, especially oral
- pseudomembrane not alwasy seen
- other inflammatory conditions can cause formation os pseudomembranes
- ischemia
- crohn’s disease
- other inflammatory conditions can cause formation os pseudomembranes
Compare and contrast crohn’s and ulcerative colitis
What part of the GI tract do they affect?
distribution?
inflammation?
stool characteristics?
- Crohn’s disease
- may involve any area of GI tract
- may ONLY involve small intestine
- patchy distribution
- transmural inflammation
- going to ilicit a response from the periintestinal fat & serosa – causing microperforations, so fat wraps around these areas of inflammation
- very thick colonic walls
- abdominal pain, diarrhea (may or may not be mildly bloody)
- may involve any area of GI tract
- Ulcerative colitis
- only affects colon and rectum
- diffuse distribution
- inflammation limited to mucosa and submucosa
- thin walls & atrophic
- at risk for toxic megacolon
- tissue that reamails un-ulcerated looks like a polyp
- really bloody diarrhea, and mucus
- both have an induced risk of adenocarcinoma
What GI diesease is indicated by the photo?
Intestine is tryign to repair itself & not doing a great job
so glands start going out sideways, sometimes don’t reach muscularis mucosae
also you can see the inflammation (dark blue) is goign all the way into the subserosal fat
Identify the histological features of chron’s disease
granulomas occur in crohn’s but not in UC, so if you get a granuloma you can immediatly diagnose crohn’s
How does the body respond in an attempt to heal the inflamed bowel for a patient with Crohn’s?
- you can get strictures
- that can lead to obstructions
- We don’t like to take sections of the bowel out of crohn’s patients because they often fistulize aftewards
- but sometimes they get so strictured that you have to
- creeping serosal fat as a response to perforation adn serositis
- does not happen in UC
What GI disease is indicated by the provided mucosal slides?
- the top two photos are exactly the same for crohn’s
- but the bottom one, notice the inflammation does not goe the full thickness of the bowel
What disease is shown by the provided images?
Which photo is Crohn’s and which is UC?
Check this out
Which images shows which microscopic colitis?
- Lymphocytic colitis (looks like celiac disease)
- glands fairly normal in shape & distribution
- marked increase in lymphocytes in the epithelium
- Collagenous Colitis
- profound thickening of supepithelium collagen table
- it likes to wrap around the superficial capillaries
- some schelpping of the epithelium
Where are the weak spots of the colon?
What can happen here?
- outer longitudinal layer of the colon is discontinuous
- layers between taenia where there is no external layer
- same space where feeding vessels supply the superficial part of the colon
- area of weakness & it is where we get diverticula
- can get inflamed & rupture causing a pericolonic abscess or peritonitis
- if not inflamed it is called diverticulosis / if it is inflamed it is called diverticulitis
How do patients with colonic diverticular disease often present?
- Present
- cramping
- lower left abdominal pain
- disorder of sigmoid colon
- bloody diarrhea
What are the hamartomatous polyps?
- Juvenile/ retention (child)
- in children
- sporadic (few polyps) or syndromic (3 to many, may develp dysplasia, at risk for other malignancies)
- <5 y/o
- rectosigmoid colon
- rectal bleeding, intussusception, obstruction, prolapse
- pedunculated
- mutations sometimes present? Hamartoma?
- may be seen in cronkhite - candida syndrome
- alopecia, nail atrophy, hyperpigmentation
- Peutz Jegher polyps - rare, autosomal dominant ( loss of function mutation in STK11)
- sporadic or syndromic
- median age 11 y/o
- melanotic oral mucosal / cutaneous pigmentation
- risk of intussusception
- increased rsk on various unusual neoplasms
What type of polyps are hyperplastic?
are they pre-cancerous?
- Epithelial polyps
- not pre-cancerous
- often tiny mucosal protrusions
- often multiple in rectosigmoid colon
- due to delayed shedding of epithelium
What type of polyp is sessile serrated polyp?
Is it pre-cancerous?
- Epithelial polyp
- diagnosis based on microscopic morphology
- serrate glandular architecture extendign down to polyp base with lateral spread adn crypt dilation
- most commonly found in right colon
- typically 1 cm or greate
- considered pre-malignant
- mismatch repair pathway
What type of polyps are shown in the provided images?
