diverticula of the bowel Flashcards
what are the 2 types of diverticulum.
1- True “congenital” diverticulum e.g. merkels lined by all layers of the GI wall.
2-acquired “false” pseudo diverticulum.
Is diverticulosis of the colon acquired or congenital
acquired
define diverticulosis of the colon.
protrusions of the mucosa and submucosa through the bowel wall.
what layers of the gut wall does diverticulosis of the colon involve
mucosa and submucosa
in which part of the colon does diverticulosis of the colon typically occur
sigmoid colon
where are divertculi in the colon located
between the mesenteric and antimesentrtic taneia coli
what type of diet protects you from developing diverticula
high fibre diets
what is the pathogenesis of diverticulosis formation
increased intra-luminal pressure- ➢ Irregular , uncoordinated peristalsis.
mucosal outpouches at points of relative weakness occur in the bowel.
weakness are due to penetration by nutrient arteries between the mesenteric and anti mesenteric taneia coli and age related elastosis in the taenea coli
what change occurs in the bowel bowel in prediverticular disease
the muscularis propria thickens.
what are the clinical features of diverticular disease
most commonly asymptomatic
cramping and abdominal pain
alternating constipation and diarrhoea
acute and chronic complications
what are acute complications of diverticula disease
diverticultitis- inflammation
peridiverticular abcess- ulceration caused by bacteria resulting in an abcess.
perforation
haemorrage- ulceration in an artery or vein.
what are the chronic complications of diverticula disease
intestinal obstruction
fistula- urinary, bladder, vagina.
diverticular colitis- inflammation of the lining
polypoid prolapsing mucosal folds.
common pathogens which cause acute colitis
campylobacter, salmonella, CMV.
what can cause acute colitis
infection, immunosuppressed people, antibiotics, drugs, ischameia, radiation, neutropenia.
what causes chronic colitis
ischemia, diverticular, chronic infections (TB), eosiniphils, radiation, collagen and lymphocytes
what 3 conditions fall under the category of idiopathic inflammatory disease
ulcerative colitis
crohns
intermediate colitis-( mix of crowns and UC)
crohns of ulcerative colitis- which one is more common in children and females
Crohns
risk factors for UC and crohns.
Oral contraceptives
Childhood infections
domestic hygiene
familial clustering
what 2 substances are protective against UC but are risk factors of crohns
smoking, appendicectomy.
clinical presentation of ulcerative colitis
diarrhoea constipation rectal bleeding abdominal pain anorexia weight loss anaemia.
complications of ulcerative colitis
toxic mega colon- – Bowel wall dilates and thins, gas and fluid accumulate and can perforate release it. treatment is steroids and cephlasporin haemorrhage stricture carcinoma
features macroscopically for ulcerative colitis
rectum and extends to rest of colon
define proctosigmoditus
sigmoid and rectum
define pan colitis
rectum to caecum
is ulcerative colitis continous throughout the affected region
YES.
freatures microscopically of ulcerative coltiis
inflammation of restrict mucosa
Crypt abscess typical of UC- contains neutrophils.
clinical features of crohns disease
chronic relapsing and flare ups. mout to anus diarrhoaea colicky abdominal pain palpable abdominal mass weight loss/failure to thrive anorexia fever oral ulcers perinanal disease- strictures and fistulas anaemia
which part of the colon does crowns disease typically affects
iliocolic region
features of a macroscopic crohns colon
illiocolic- thickened and inflamed bowel lumen
cobblestone appearance due to longitudinal and transverse strictures.
pathcy appearance- skip lesions
apthoid ulcer
features of a microscopic crohns colon
compact epitheliod cell granuloma- all layers of the bowel wall, found in liver and regional lymph nodes.
complications of crowns
toxic mega colon perforation fistula stricture haemorrhage carcinoma short bowel syndrome- from numerous resections
which condition is transmural crohn or ulcerative colitis
crohns
which condition only affect the mucosal layer
ulcerative colitis
which condition are granulomas present crohn or ulcerative colitis
crohns
which condition are crypt abcesseses common
ulcerative colitis.
what hepatic manifestations occur in IBD
Fatty chnage
granulomas
primary scleroising colongitis-inflammation and fibrosis scarring of the bile ducts.
bile duct carcinoma
what skeletal changes occur in IBD
polyarthritis
sacro-iletis
ankolysing spondylitis
what mucocutaneous changes occur in IBD
Oral apthoid ulcers
Pyoderma gangrenosum- ulcers
Erythema nodosum- skin inflammation
what ocular changes occur in IBD
- Iritis/uveitis
- Episcleritis
- Retinitis- inflammation of the retina.
what renal changes occur in IBD
• Kidney and bladder stones
what haematological changes occur in IBD
- Anaemia
- Leucocytosis
- Thrombocytosis
- Thrombo-embolic disease- DVT
what systemic changes occur in IBD
- Amyloid deposition.
* vasculitis
what are the risk factors for developing colorectal cancer
- Early age of onset
- Duration of disease
- Total or extensive colitis- how much colon is affecting.
- PSC
- Family History of cancer.
- Severity of inflammation (pseudopolyps)
- Presence of dysplasia (pre- malignant neoplasm).
how is colitis surveillance performed
- After 10 years UC colonscipic is offered to all patients every few years.
- Take a biopsy and use it to see if any dysplasia is present.
- The more active the disease the increased frequency of colonscopy.
what layer of the colon forms colorectal polyps
mucosal protrusion
3 types of colorectal polyps
sensile- no stalk
pedunculated- stalk
flat
How are polyps classified
- Neoplastic, harmartomatous (disorganised proliferation of normal bowel), inflammatory and reactive.
- Benign or malignant
- Epithelial or mesenchymal
the most common type of non-neoplastic polyp
hyperplastic polyp
is Harmartomtous polyp begin or malignant
beingin
2 conditions which result in harmartomtous polyps
Peutz-jeghers polyps
Juvenile polyps
most common site for hyper plastic polyp
rectum and sigmoid
are hyperplactic polyps malignant or benign
Small distal HP’s have NO malignant potential.
Large right sided hyperplastic (caecum) polyps sessile serrated (broad-based polypoid lesion without a clear stalk.) may give rise to microsatellite unstable carcinoma
commoest polyp in children
juvenille polyp
what shape is a juvenile polyp
spherical
most common site for juvenile polyps
rectum and distal colon
are juvenile polyps malignant or benign
Juvenile polyposis (lots of them) associated with increased risk of colorectal and gastric cancer- FH
Sporadic polyps have no malignant potential
what type of genetic condition is PEUTZ-JEGHERS SYNDROME
autosomal dominat
clinical presentation of PEUTZ-JEGHERS SYNDROME
abdominal pain (intussusception), gastro-intestinal bleeding and anaemia. Muco-cutaneous pigmentation- brown patches lips, fingers toes and lining of cheeks.
where are PEUTZ-JEGHERS SYNDROME polyps found.
small bowel and stomach.
can form in the gallbladder, urinary bladder and nasopharynx.
what cancer do PEUTZ-JEGHERS SYNDROME predispose you to
colon, stomach and breast.
what are the different types of benign neoplastic polyps
- Adenoma
- Lipoma
- Leiomyoma
- Haemangioma
- Neurofibroma
what are the different types of malignant neoplastic polyps
- Carcinoma
- Carcinoid
- Leiomyoscarcoma
- GIST
- Lymphoma
- Metastatic tumour.
what type of tumours are adenomas
benign
epitheliod tumour
what shape are adenomas
polyp shape
what typeof cancer are adenomas precursors to
colorectal cancer.
which part of the colon has lager adenomas
recto-sigmoid and caecum
features of macroscopic adenomas
pedunculated(stalk), sessile(broad base) or flat.
Architectural Type : villous, Tubulo-villous or tubular- villi or smooth surface with tubules.
what types of adenoma are more likely to form cancer
think about size and architecture
larger
Flat adenomas- only raised above the mucosa and higher risk of dysplasia.
villious
risk factors for colorectal cancer.
sporadic- most common
FH- single gene, HNPCC, FAP
IBD,diet, obesity, alcohol, • Hormone replacement therapy and oral contraceptives, Schistosomiasis, Pelvic radiation
what form of medication id protective for colorectal cancer
NSAIDS
which inherited codlins predisposes 100% to colorectal cancer
FAP
what types of polyps does FAP cause
multiple benign adenomatous polyps
HNPPC an FAP are both what type of genetic condition
autosomal dominat
what condition does a mutation in a APC tumour suppressor gene cause
FAP
what condition does a mutation in a DNA mismatch repair gene cause
HNPCC
what cancers other than colorectal does HNPCC predispose to
endometrial, ovarian, gastric, small bowel, urinary tract and billary tract cancer.
where are most colorectal cancers located
2/3 of cancer’s are distal to the splenic flexure.
what are the different types of colorectal cancer in terms of different tumours
Adenocarcinoma-most common Adenosquamous carcinoma Squamous cell carcinoma Neuroendocrine carcinoma undiffrentaited carcinome medually carcinoma
how are tumours graded
Well differentiated
Moderately well differentiated
Poorly differentiated - bad prognosis
how does colorectal cancer spread
- Direct invasion of adjacent tissues
- Lymphatic metastasis (lymph nodes)
- Haematogenous metastasis (liver and lung)
- Transoelomic (peritoneal) metasis
- Iatrogenic spread eg. Needle track recurrence, port site recurrence.
what 2 forms of staging are used for colorectal cancer
TNM
Duke’s staging
what does the T part of TNM determine
tumour- what layers has the tumour crossed.
• T1-mucosa and some submucosa.
• T2- muscularis propria
• T3-connective tissue
• T4-ulcertive peritoneal lining perforation or invades another organ e.g. vagina etc.
what does the N part of TNM determine
nodes
➢ N0 no nodes involved
➢ N1 1 – 3 nodes involved
➢ N2 4 or more nodes involved
what does the M part of TNM determine
metastases
➢ M= distal metastases.
➢ M0= NO metastases
➢ M1=METASESES.
how many stages are there in duke’s staging
and what defines in each stage
4
• Stage A : adenocarcinoma confined to the bowel wall with no lymph node metastasis
• Stage B : adenocarcinoma invading through the bowel wall with no lymph node metastasis
• Stage C : adenocarcinoma with regional lymph node metastasis regardless of depth of invasion
• Stage D : distant metastasis present
stage D worst.
