GI Flashcards
What is Bouveret syndrome?
Due to impaction of gallstone at level of pylorus or proximities duodenum.
Obstruction at level of proximal duodenum with resultant gastric outlet obstruction
What are features of malignancy in side branch and main duct IPMNs?
What are the CT features of pancreatic serous cystadenoma?
What age are patient usually?
Older patient in 70’s
Multicystic mass in the pancreatic head ‘bunch of grapes’
Central scar present with cysts around it. Calcification can be present
- Individual cysts usually <2cm
- At least x6 cysts usually
NO visible communication between cysts and pancreatic duct
What are features of a MUCINOUS cystadenoma of the pancreas?
What age group and sex?
Classically middle aged women in 40’s
Cystic tumour favouring pancreatic tail
Individual cysts usually >2cm
IF left long enough will transform into mucinour cystADENOcarcinoma
What are features of pancreatic adenocarcinoma?
Does it enhance on CT?
What features define it inoperable?
Poorly enhancing mass
Low survical rate
Most are unresectable at diagnosis (90%)
Tumour markers CEA and CA 19-9
What features are more suggestive of gastric carcinoma over gastric lymphoma?
Which crosses the pylorus?
Gastric carcinoma will usually cause Gastric outlet obstruction
-extension beyond serosa and focal mass are more suggestive
Gastric Lymphoma DOESNT cause gastric outlet obstrction
-Commonly crosses the pylorus
Pancreatic tail tumour with thick capsule and progressive fill in of solid components in a young Asian woman
What is diagnosis?
Solid pseudopapillary tumour
Low grade malignant tumour
Occurs in young female Black/Asian women
Pear shaped bladder, elevated sigmoid colon and straightening of rectum in middle aged person barium enema
What is diagnosis?
Think pelvic lipomatosis - overgrowth of fat cells in the pelvis
Typical in young to middle aged adults
Causes of infective colitis according to site?
What causes right sided colitis?
Hernia locations
What are 5 differentials for low attenuation ENLARGED mesenteric lymph nodes?
- TB
- Coeliac
- Necrotic mets
4.
What causes cavitating mesenteric lymph node syndrome?
Coeliac disease
Seen in patients who arent compliant with gluten free diet
-chronic inflammation of duodenum/jejunum and draining LN
What is the appearance of Zenker diverticulum on barium swallow?
Where is it located
Posterior outpouching of oesophagus at level of C5-6
Arise from Killians Dehiscence
(Different from Killian Jamieson diverticulum)
-this is left sided outpouching just below the cricopharyngeus muscle
What part of the bowel does Typhilitis predominantely effect?
Caecum - cacael wall thickening and oedema
Typically in immunocompromised patients undergoing chemotherapy (commonly induction chemo pre bone transplant)
Where does abdominal TB mostly affect?
How to differentiate from Crohns?
Ileocaecal juntion - thickening of valve with narrowing of terminal ileum
-skip lesions also present like crohns
In over 50% of cases - abdominal TB will present with ascites (good differentiator for Crohns)
True cyst vs false cyst features?
True cysts have epithelial lining - false ones dont
False cysts can be seen in Spleen after trauma and represent result of haematoma or infarction
Name differentials for widening of presacral space?
What are the rules for Meckels diverticulum?
Located in the distal ileum
Lumen is wide than that of ileum
Can cause:
- obstruction
- haemorrhage
- diverticulitis
The ‘rule of 2s’ is a useful aide-mémoire
2% of the population
2:1 male: female ratio
2 feet from the ileocaecal valve
2 inches in length
2 types of common ectopic tissue (gastric and pancreatic)
2 years most common age at clinical presentation
Where are pre aortic lymph nodes located and what are they?
Located anterior to aorta around origins of coeliac, SMA and IMA
Drain:
- GI tract
- Liver, spleen and pancreas
1. Coeliac
2. SMA
3. IMA
Autoimmune pancreatitis features?
Part of the IGg4 related disease
-Diffusely enlarged ‘Sausage shaped’ pancreas
-Some pancreatic duct dilatation may be present due to stricturing
-Enhancement might be delayed due to fibrosis
Reposonsive to steroids
Portosystemic anastomosis and their conditions
Haemorrhoids?
Oesophageal Varices?
Capud medusae?
What is pseudomyxoma peritoneii?
Where rupture of an appendix mucocele (usually) results in filling of peritoneal cavity with mucinous fluid.
Scalloping of the liver by solid fluid density masses is typical
Where is dentate line?
Lymph node drainage above and below dentate line is to which lymph nodes?
Dentate line divides the upper 2/3 from lower 1/3 of anal canal
Above line = drainge is to internal iliac lymph nodes
Below line = drainage to superficial inguinal lymph nodes
Summary of polyposis syndromes
What are CT features of GIST tumours?
70% occur in stomach
Small percentage can occur in small bowel
-Dysphaga and early satiety due to mucosal ulceration/haemorrhage
Tend to enlarge extraluminally into lesser sac or gastrohepatic or gastrosplenic ligaments
Can be expohytic with necrotic centre
Lymph node enlargement is NOT A FEATURE
Tend to have CENTRAL NECROSIS
Associated with Carneys Triad and NF1
- Pulmonary chondromas
- -Extra-adrenal pheo*
- -GIST*
What TMN classification does spread beyond the mesorectal fascia?
Rectal cancer staging
T4
MRI is excellent for local staging of rectal cancer because the mesorectal fascia is seen clearly as a thin black line on T2 weighted sequences and its involvement or lack thereof can be readily discerned. In contrast, the tumour appears as intermediate signal on T2, distorting the normal anatomy.
Cystic duct insertion variations?
Which is normal insertion?
What is most common anomaly?
Normal cystic duct insertion is within middle third of extrahepatic duct (75%)
-Most common variation is middle third posterior insertion (20%)
-followed by low medial insertion (5%)
Name 5 features of haemochromatosis?
- Diabetes
- Liver cirrhosis
- Hook like osteophytes on the radial aspect of metacarpal heads
- Chondrocalcinosis
- Congestive cardiac failure
What is most common rectal cancer?
Adenocarcinoma in 98% cases
If returns as squamous then HPV is usually underlying diagnosis (can be anal also)
- Once cancer breaches the serosa and involves mesorectal fact (within fascia) it is T3*
- If it breaches mesorectal fascia it is T4*
Treatment
Treatment depends on invasion and position relative to the anal verge
- High rectal tumours - low anterior resection and will maintain continence*
- Low rectal tumours - treated with abdominoperineal resection and will end up with colostomy*
What is cowdens syndrome?
COWS BUTT
Multiple hamartoma syndrome
Multiple hamartomas in the body, particulary in small, large bowel.
Assc with breast, uterine and thyroid cancer
Autosomal dominant
What is Turcot syndrome?
Glioblastoma and multiple colonic polyps are features
What is McKittrick-Wheelock syndrome?
Seen in old women
Villous adenoma causes diarrhoea and resultant:
- low chloride
- low sodium
- low potassium
What are appearances of carcinoid?
Low grade and slow growing
Starburst appearance of mesenteric mass with calcifications
Most commonly arises in appendix or distal ileum however may not be able to see mass.
Metastases will appear as a large mesenteric mass containing flecks of calcification
Liver mets appear hypervascular
Systemic serotonin degrades heart valves on right side (commonly causing tricuspid regurg)
MIBG or Octreotide scans for diagnosis
Where does TB of the GI tract usually arise?
Most commonly affects ileocaecal junction with thickening of the ileocaecal valve and narrowing of terminal ileum
Over half of cases will have ascites
Cause of colitis depending on distribution?
What causes right sided colitis?
What causes left sided?
Right sided = Salmonella or shigella
Left sided = Schistosomiasis
Rectosigmoid = Gonorrhoea, herpes, chlamydia
Diffuse = CMV and e coli
Barium apperances of small bowel differentials
What is Menetrier Disease?
Triad of:
Glandular hypertrophy
Achlorhydia (stomach doesnt produce HCL)
Hypoproteinaemia (low albumin)
-Swollen ankles
-Low albumin
-Distended stomach
-SPARING OF ANTRUM (in contrast to lymphoma which involves antrum)
What are differentials for hepatic capsular retraction?
- Cholangiocarcinoma
- Fibrolamella HCC
- Metastases
- IgG4 disease
- Cirrhosis
Differentials for polyposis syndromes
Types of perianal fistulae?
Which is most common?
Intersphinteric is most common = does not cross external sphincter, remains medial to it
What are mesenteric desmoid tumours?
How do they appear?
What are they assocaited with?
Should be thought of in differential of mesenteric mass
Benign fibrous lesions (Low on MRI)
- Develop at root or small bowel mesentery, large and well defined
- Isodense to muscle on CT
Associated with FAP
What happends in fundoplication?
What are complications?
Gastric fundus is wrapped around the lower end of oeseophagus = reenforces lower oesophageal sphincter
Early complication = obstruction
Signs of failure
Reflux or hiatus hernia (these were reasons it was done in first place)
How to tell if a fundoplication has slipped?
Slippaged of oesophagus back towards chest. Lower oesophagus above wrap will be >2cm.
What are epiphrenic diverticula?
Diverticula arising from the distal oesophagus
Usually right sided
- Considered pulsion type (tend not to empty due to lack of muscle)*
- Are associated with oesophageal dysmotility*
- Can be assocaited with paraoesophageal hernia*
What is traction diverticula?
Mid oesophageal diverticula
Usually due to scarring (granulomatous disease, TB, pulmonary scarring, fibrosis)
Considered Traction diverticula (triangular in shape and will empty)
What is oesophageal pseudodiverticulosis?
What age group?
Usually older aged 50 - 70 years
- Multiple small outpouchings of the oesophagus due to submucosal gland dilatation*
- Can be seen with Oesophageal strictures and GORD*
What does an oedophageal web look like?
A thin mucosal membrane projecting into the lumen
- Cervical oesophagus near cricopharyngeus*
- Assocated with Plummer vinson syndrome*
- Usually asymptommatic*
- If stenosis is severe = can cause regurg etc*
What is Gardner syndrome?
What are features?
- FAP*
- Desmoid Tumours*
- Osteomas*
- Papillary thyroid cancer*
Peutz jeghers vs Cowden
Peutz-Jeghers
Multiple hamartomas
Mucocutaneous pigmentation
Ass with small and large bowel cancers, pancreatic cancer, gynae cancers
Cowden Syndrome
Multiple hamartomas
Assc with Breast ca, Thyroid Ca,
Trichilemmomas (benign tumours of hair follicles)
Most common stomach tumour?
Adenocarcinoma >95%
Lymphoma <5%
Metastatic spread to the ovary is known as Krukenberg Tumour
- GIST is usually exophytic*
- Adenocarcinoma is large, ulcerated heterogenous mass*
Name different mets to the stomach
What are origins?
Mets to stomach are rare
Melanoma is most common
-multiple button like soft tissue nodules
Breast and Lung mets
Can give appearance of Linitis plastica
Stomach looks diffusely thickened with narrowing of the lumen
- Lymphoma of stomach can appear similar*
- -common primary stomach tumour giving linitis plastica appearance is a scirrhous adenocarcinoma*
What is entamoeba histolytica?
Parasitic infection causing Amoebic abscess in other words
- -causes bloody diarrhoea and is a cause of toxic megacolon*
- -appear as ‘flask shaped’ ulcers on endoscopy*
- -can cause liver and brain abscesses (can persist up to 2 years)*
Spares terminal ileum
What is Peliosis?
Rare beign vascular condition
Multiple blood filled spaces in the liver and spleen
Low T1
High T2
Enhancement
Thought to be assc with OCP in women & men on anabolic steroids
Also seen in:
- AIDS
- Renal transplant patients
Common splenic cystic masses
Name 4
(Below is Hydatid)
Post traumatic cysts
Occurs secondary to infarction, infection, haemorrhage or trauma
Most common cyst
(No epithelial lining therefore ‘pseudocysts)
Epidermoid Cysts
Second most common
Have epithelial lining
Large and slow growing - are usually around 10cm
Can have wall calcification
Hydatid or Echinococcal cysts
Caused by Echinococcus
Usually consist of a spherical ‘mother cyst’ containing smaller daughter cysts
When there is detachment of the cyst membran - it is seen as floating within other cysts Water lily sign
What features help differentiate sigmoid volvulus vs caecal?
Ahaustral pattern in sigmoid volvulus
Epiploic appendagitis vs omental infarct
How to differentiate?
What are Ladds bands?
What do they cause?
Fibrous bands connecting abnormally placed caecum (due to malrotation) to the liver
Results in duodenal obstruction
What is colitis cystica?
Cystic dilatation of mucous glands
Can be Superficial - small cysts throughout colon. Assc with vit def, tropical sprue, leukaemia.
or
Profunda - cysts in rectum and sigmoid which are large
Features of benign gastric ulcer?
Protrudes beyond stomach
- Deep
- Round
- Symmetric
Splenic Injury
