Question 1

What is the rule of 2's with meckel's diverticulum?

Accepted Answer

2 years old on presentation, 2 inch long 2% of pop affected. 2:1 male:female ratio for symptomatic presentations; location most commonly 2 feet (60 cm) proximal to ileocaecal valve in adults; 2 types of ectopic tissue (gastric and pancreatic); one half of those symptomatic are younger than 2 years of age.

Question 2

Name 4 classes of cancer?

Accepted Answer

carcinoma - appears to be epithelial origin, sarcoma - appears to be ct/supportive cell origin, myeloma - appears to be of plasma cell in bone marrow, leukaemia - appears to be from bone marrow.

Question 3

whats hyperplasia, neoplasia and dysplasia?

Accepted Answer

increase in number of cells subject to growth stimuli =hyperplasia increase in number of cells not as a result of normal growth stimuli =neoplasia loss of normal morphology = dysplasia

Question 4

what is the grade of a tumour?

Accepted Answer

how well or poorly differentiated it is

Question 5

how many body cells at any one point are dividing?

Accepted Answer

Less than 1%.

Question 6

name 3 classes of genes that are altered frequently in cancer?

Accepted Answer

proto oncogenes, ts genes, microRNA genes( inhibit translation of mrna produced by some genes) Mutator genes

Question 7

what is a KRAS? describe its function?

Accepted Answer

It is a gtpase. It is a proto oncogene. EGF binds to receptor causes Sos protein to displace gdp from ras. RAS binds to gtp and recruits raf1 which initates a MAP kinase cascade and eventually producing erk goes into nucleus and activates transcription factors for cell division. RAS is turned off by gap which makes ras hydrolyze gtp.

Question 8

what gene is found in 50% of cancers and how does it work?

Accepted Answer

TP53 - is a transcription factor = guardian ts. dna damage - p53 is phosphorylated and turns on dna repair genes and transcribes p21 which binds to g1-s checkpoint cdk4-cyclin d and inhibits activity.

Question 9

what are mutator genes ? name 2?

Accepted Answer

DNA repair genes. and HMSH2 ans HMLH1

Question 10

what is replicative senescence?

Accepted Answer

limitation of number of times cells can divide due to telomere shortening

Question 11

How does the APC protein work?

Accepted Answer

Builds complex with gsk3Beta, which binds to beta caternins in cytoplasm(have come from adherens contacts between cells) mark it for degradation and prevents it from translocated into the nucleus where it acts as a transcription factor for a proliferation gene.

Question 12

how can tell stomach bubble vs free intra abdo gas apart?

Accepted Answer

stomach bubble has thick wall

Question 13

what is chilaiditi's phenomenon?

Accepted Answer

cirrhosis or flattened diaphragm (lung hyperexpansion) void created above liver and is filled with bowel - may mimic free gas (pseudoperitoneum)

Question 14

what is considered to be dilated small bowel?

Accepted Answer

over 3cm

Question 15

describe 2 features of small bowel obstruction?

Accepted Answer

valvulae conniventes visible, centrally located multiple dilated loops

Question 16

what indicates ileus on axr?

Accepted Answer

sentinel loop (Simply put, it is the dilatation of a segment of small intestine. to be differentiated from colonic cutoff sign which is a dilatation of a segment of large bowel.)

Question 17

name the 2 most common causes of large bowel obstruction?

Accepted Answer

crc and diverticular strictures

Question 18

and 2 less common causes?

Accepted Answer

hernias and volvulus

Question 19

define large bowel obstruction in caecum and colon?

Accepted Answer

over 9cm and over 6cm

Question 20

what are 2 most common types of volvulus? whats an axr sign ?

Accepted Answer

sigmoid and caecal and coffee bean sign

Question 21

what is a axr sign of bowel wall inflammation?

Accepted Answer

thumbprinting = mucosal thickening

Question 22

describe the 5 steps in the classical genetic pathway for CRC?

Accepted Answer

1. APC mutation(=gatekeeper) 2.KRas mutation early to intermediate adenoma 3. intermediate to late adenoma - smad 2 and 4. TS genes mutating (both act in tgf beta pathway) 4. late adenoma - adenocarcinoma - tp53 lost 5. loss of e-cadherin function - tumour invasion and metastasis

Question 23

what happens when have a mutation in a DNA mismatch repair gene?

Accepted Answer

hypermutation - microsatellite instability - sequences get longer or shorter.

Question 24

what does microsatellite instability indicate?

Accepted Answer

lack of response to fluroouracil (5-FU) chemotherapy

Question 25

describe FAP? % of crc? what is it characterised by? inheritance?

Accepted Answer

100 tubovillous adenomas in colon. autosomal dominant. all gene carriers have polyps by 40 years.

Question 26

name a variant of FAP?

Accepted Answer

gardiner's syndrome - GI polyps, multiple osteomas and skin and soft tissue tumours.

Question 27

describe lynch syndrome? how is it diagnosed? what mutations? inheritance? % of all CRC?

Accepted Answer

also known as hereditary non polyposis colon cancer (HNPCC) diagnosed through family history and molecular testing. mutations in 4 mismatch repair genes - MLH1, MSH2, MSH6, PMS2. autosomal dominant. 2-5% of CRC

Question 28

name 2 rarer CRC syndromes?

Accepted Answer

turcot syndrome and peutz jegher syndrome

Question 29

what is epigenetics?

Accepted Answer

study of changes in gene expression that is not due to change in dna sequence

Question 30

name the 3 types of adenoma? what is the largest and worst?

Accepted Answer

tubular, tubulovillous and villous(worse one). tubular are the smallest then its tubulovillous and then its villous.

Question 31

what do sessile polyps look like?

Accepted Answer

slightly flattened broad based polyps.

Question 32

name 2 premalignant lesions in crc? whats an adenoma ?

Accepted Answer

traditional serrated adenoma and sessile serrated adenoma(flat in appearance) A polyp that resembles normal lining of the colon.

Question 33

what does the lacunar ligament do?

Accepted Answer

connects inguinal ligament to pectineal ligament(runs on pectineal line)

Question 34

what is the conjoint tendon?

Accepted Answer

structure formed from lower part of transverse abdominis and inter oblique aponeurosis that inserts into the public crest and pectineal line immediately behind the superficial ring

Question 35

is their a difference between genders in CRC? Give 9 risk factors?

Accepted Answer

men get it more, smoking, obesity, diabetes, asbestos exposure, low fibre diet, red meat and animal fat(increase risk) aspirin and nsaids increases with age, UC.

Question 36

what % of crc are sporadic?

Accepted Answer

80-90%

Question 37

What side and at what age does lynch syndrome present? Name 1 thing in family history that is typical?

Accepted Answer

right and in those less than 50 years. Family members have a history of gynaecological malignancy.

Question 38

what are the 4 tumour types in CRC?

Accepted Answer

polypoid (resemble a polyp), ulcerating, annular, infiltrative.

Question 39

what is penetrance?

Accepted Answer

the proportion of individuals carrying a particular gene who display the phenotype

Question 40

what does pedunculated mean?

Accepted Answer

structure with a stalk

Question 41

what is mean age of development in fap? and average age of cancer? what other cancers can occur in fap?

Accepted Answer

16,39, and thyroid and pancreatic

Question 42

what is commonest cause of death in patients with FAP who have been colectomized?

Accepted Answer

duodenal adenomas

Question 43

whats attenuated FAP?

Accepted Answer

presents later - fewer polyps more on right side

Question 44

describe 4 other CRC syndromes?

Accepted Answer

MYH associated polyposis - have FAP phenotype - base excision repair gene mutation (MYH) Turcots sundrome - FAP or Lynch with brain tumours Juvenile polyps - mutation in SMAD4 - large stalked polyps. polyps throughout GI Peutz jegher syndrome - multiple hamartomatous polyps (benign tumour like malformation) in SI and colon as well as pigmentation around lips, mouth and digits.

Question 45

give 1 symptom of ileocaecal valve cancer? 3 for right sided colon cancer? 3 for left sided? and 3 for rectal?

Accepted Answer

small bowel obstruction. iron deficiency anaemia, weight loss, palpable mass. rectal bleeding, altered bowel habits, obstruction. fresh red rectal bleeding, tenesmus, mass

Question 46

name 8 tests/ investigations that could be done in CRC?

Accepted Answer

sigmoidoscopy (rigid -25cm, flexible -60cm), colonscopy, barium enema. If tumour found - Carcinoembryonic antigen(CEA), CT/MRI and Liver USS - see if spread to Liver. PET. If family history of FAP - DNA test.

Question 47

what is CEA also increased in? and hence why not used for screening?

Accepted Answer

COPD, crohns, pancreatitis

Question 48

What was the old classification criteria for CRC? whats the new one?

Accepted Answer

dukes, TNM T0 - intraepithelial or lamina propria only T1- invades submucosa T2- invades muscularis propria T3 - invades subserosa T4 - directly invades other tissues N1 - 1-3 regional nodes N2 - 4 or more regional nodes

Question 49

4 types of surgery in CRC? % that have surgery?

Accepted Answer

80%. right hemicolectomy. left hemicolectomy. sigmoid colectomy. anterior resection - low sigmoid or high rectal

Question 50

What surgery is used for low rectal tumours?

Accepted Answer

Abdomino-perineal (AP) resection: for tumours low in the rectum (less than approximately 8 cm from the anal canal). Permanent colostomy and removal of rectum and anus.

Question 51

what chemo regimen in CRC?

Accepted Answer

folfox regimen

Question 52

prognosis in CRC?

Accepted Answer

overall 5 year survival = 50%

Question 53

what does hamartomatous mean?

Accepted Answer

benign tumour that grows at same rate as surrounding tissue

Question 54

Describe NHS bowel screening programme?

Accepted Answer

screening every 2 years between 60-75 - faecal occult blood

Question 55

what are risk factors for sigmoid volvulus? how is it tx?

Accepted Answer

men, elderly, chronic constipation. flatus tube

Question 56

Name 4 clinical features of bowel obstruction?

Accepted Answer

CAVA. C= colicky abdo pain. A=abdo distension. V=vomiting. A=absolute constipation(doesn't have to be absolute)

Question 57

Difference between a large bowel and small bowel obstruction?

Accepted Answer

SIO - vomiting earlier, distension less pain higher LIO - pain constant

Question 58

Name 2 types of bowel obstruction? 5 investigations in bowel obstruction?

Accepted Answer

simple or closed loop. FBC, U+E, AXR, CT gentle contrast medium gastrogaffin.

Question 59

whats conservative tx for small bowel obstruction?

Accepted Answer

drip and suck - NBM, nasogastric tube to decompress stomach - removes swallowed air, and prevents aspiration. IV fluids and correct electrolytes.

Question 60

what do u do in large bowel obstruction?

Accepted Answer

surgery

Question 61

Name 3 causes of paralytic ileus?

Accepted Answer

peritonitis, handling intestines and opiates

Question 62

Define Diverticular disease? Diverticulosis? Diverticulitis? Acute diverticulitis? epidemiology of diverticular disease? % assymptomatic?

Accepted Answer

Colonic diverticulosis refers to herniation of mucosa and submucosa through the muscular layer of the colonic wall. Diverticular disease may be defined as any clinical state caused by symptoms pertaining to colonic diverticula. Diverticulitis indicates inflammation of a diverticulum or diverticula and may be caused by infection. Other complications of diverticular disease include segmental colitis, lower gastrointestinal bleeding, infection, abscess, perforation, peritonitis, and fistula formation. 50% of all people by the time they are 50 years. 70% of people by 80 years. 75% are assymptomatic. INCIDIENCE INCREASES WITH AGE. Vegetarians have been shown to have a lower incidence of diverticular disease.

Question 63

Describe the pathology of Diverticular disease ? AETIOLOGY? CLASSIFICATION?

Accepted Answer

Thought to be multifactorial. low fibre diet - high luminal pressures - mucosa herniate through muscle layers - diverticula. 95% in sigmoid. The sigmoid colon is commonly affected because of its small diameter. Other aetiological theories are altered colonic wall structure, and connective tissue abnormalities. Other predisposing factors described include decreased physical activity, obesity, increased red meat consumption, excessive alcohol and caffeine intake, steroids, and NSAIDs. Acute diverticulitis is more common on the left side in the sigmoid region, whereas diverticular bleeding originates commonly from right-sided diverticula. Microperforation of 1 or more diverticula may result in a localised phlegmon, a small confined abscess (stage I), a distant abscess (stage II), generalised peritonitis (stage III) or free perforation, and faecal peritonitis (stage IV). These stages are Hinchey's classification.

Question 64

Presentation of diverticular disease? 6 features of diverticular disease

Accepted Answer

Diverticular disease should be considered in patients, usually over 40 years, presenting with left lower quadrant abdominal pain and tenderness, with or without pyrexia. Atypical presentation includes right-sided lower abdominal pain associated with right-sided colonic diverticular disease, and in younger, obese patients presenting with lower abdominal pain. In complicated diverticular disease, especially with diverticulitis and or abscess, patients will have signs of peritonism (rebound tenderness, rigidity) and may have a palpable, tender abdominal mass. CLINICAL FEATURES: nausea, vomiting, chronic progressive Lower abdo or LIF pain. altered bowel habit - constipation, bloating. Rectal bleeding(rare) Pneumaturia -frothy urine (due to colovesical fistula) faeces per vaginum - colovaginal fistula. Diverticular bleeding is usually abrupt, painless, profuse arterial lower GI bleeding. Diverticular bleeding is the most common cause of lower GI bleeding in older patients and usually originates from right-sided diverticula, especially in Asian patients.

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2.05 Rectal Bleeding: CRC, IBD, Diverticulitis, Anal fissures, Anal Fistulae, Rectal prolapse, Toxic megacolon, Lower GI bleed, Peutz Jegher, Anal cancer, Meckel's Diverticulum, Haemorrhoids, Coeliacs, IBS. Flashcards

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