GI Flashcards
Candidiasis
irregular, longitudinal plaques with intervening normal mucosa
Typically upper 1/3 oesophagus
Immunocompromised (HIV, Transplant)
In older asymptomatic patients = Mucosal white plaques more uniform, rounded, and less well defined than candidiasis = Glycogenic Acanthosis
Herpes ulcer
Immunocompromised, multiple small <1cm oesophageal ulcers with a surrounding halo of oedema
CMV or HIV
Singular large flat ulcer. 1cm in length in the oesophagus
HIV more common to have massive ulcer (can be several cms)
Barretts
Mid oesophageal stricture, associated hiatal hernia and reflux
‘reticular muscosal pattern’
Eosinophilic oesophagitis
Barium - Concentric, ring-like strictures of oesophagus
**Not transient - Permanent **
DDx
feline oesophagus
- folds1-2 mm thick and run horizontally around the entire circumference of the esophageal lumen.
- The findings are transient, seen following reflux and not during swallowing.
- Associated with GORD
- distal two-thirds of the thoracic esophagus
Caustic
long stricture ± diffuse ulceration of lower and mid oesophagus
Stomach can be pulled into the chest as the oesophagus shortens and strictures
DDX Long stricture
-NG tube in too long or radiation - These are usually smooth
oesophageal scleroderma
-affects the Lower 2/3 (smooth muscle) with atony and peristalsis that begin caudally and moves cranially.
-Moderate dilatation of esophagus with fusiform stricture at lower end
Nb upper 1/3 to above aortic arch is normal (striated muscle)
NB - Jejunum - dilated but with preserved valvulae conniventes
DDx
Achalsia
- Grossly dilated whole oesophagus with smooth, beak-like tapering at lower end
Reflux Esophagitis (With Stricture)
-Longer tapered distal stricture
-Less luminal dilation
-Distinguished from scleroderma by normal peristalsis
Esophageal Carcinoma
-Abrupt proximal borders of strictured segment (rat tail appearance)
-Mucosal irregularity, shouldering, mass effect
Nb polymositits
- affects skeletal muscle so therefore affects the upper third of oesophagus, retention of barium in the valeeculae, regurg nasal reflux, failure of contrast to progress in upper third without gravity
Oesophageal duplication cyst
Water density cyst in the posterior mediastinum
Commonest site-** distal ileum**, duodenum, oesophagus
DDx
- Bronchogenic cyst - Cartilage, **subcarinal **
- Leiomyoma - solid oesophageal mass
- Oesophageal diverticulum - communicated directly
- Neurenteric cyst - associated vertebral abnormalities
Zenker Diverticulum
Outpouching with rounded contour posteriorly in the neck is above the cricopharyngeus muscle
In hypopharynx!!!
Site of weakness is the Killian dehiscence - between the inferior pharyngeal constrictor muscle and cricopharyngeal muscle
Traction diverticulum
Dysphagia in elderly person. Previous TB.
Barium-filled tented or triangular outpouching in the mid oesophagus
Acquired condition due to subcarinal or perihilar granulomatous lymph node pathology (TB, histo)
External force on oesophageal wall, such as mediastinal inflammation, that adheres and pulls on oesophageal wall
Killian - Jamieson Diverticulum
Small outpouching in the cervical oesophagus. Anterior and lateral direction
Epiphrenic diverticulum
Large saccular outpouching just above the diaphragm, right side
Can be mistaken for paraesophageal hernia - usually in on the left
associated with dysmotility disorders
Oesophageal pseudodiverticulosis
Barium - multiple, tiny (1- to 4-mm depth), flask-like outpouchings in the oesophagus
Barium trapped in dilated excretory ducts of submucosal glands
CHRONIC REFLUX* and Candida
Plummer - Vinson syndrome
Oesophageal web, iron deficiency anaemia, dysphagia, spoon shaped nails
Webs are risk factor for hypopharyngeal and oesophageal Cancer
Pulmonary sling
Aberrant left pulmonary artery
Anterior indentation of the oesophagus and posterior indentation of the trachea
GIST
Well-circumscribed.
**Heterogenous, central necrosis is key **
Hypervascular
submucosal mass extending exophytically from GI tract
Stomach (60%) , dudoenum (30%) and oesophagus (10%)
Remember
- assocaited NF-1
- Carneys triad
- Pulmonary condromas, Exrtra-adrenal paragangliomas, GIST
Gastric lymphoma
Diffuse wall thickening
can cross the pylorus
Rarely causes gastric outlet obstruction
can be primary MALT and secondary to systemic lymphoma (NHL)
DDX
Hematogenous spread of metastases to stomach
Malignant melanoma
Bull’s-eye or target lesions, nodular intramural cavitated lesions
Breast cancer: Linitis plastica or leather bottle appearance
Markedly thickened gastric wall with enhancement, folds preserved
Mimics primary scirrhous carcinoma of stomach
gastric carcinoma
- Intraluminal mass with no peristalsis through lesion (at fluoroscopy)
- Antral mass causing outlet obstruction - Ulcer -
Width > depth, nodular edges
obliteration of surrounding areae gastricae - Infiltrative -
Diffuse infiltration of gastric wall; non-peristaltic, non-distensible = **Linitis plastica (leather bottle) ***
**Pseudoachalasia: Fundal carcinoma may destroy myenteric plexus
Oesophageal obstruction, dilated lumen, diminished peristalsis; mistaken for primary achalasia - Pseudo the GE junction doesnt relax
Krukenberg tumor: Metastases to ovaries via peritoneal seeding
Early epigastric nodes
Menetriers disease
SPARES the antrum
Hyperplastic gastropathy/ protein-losing gastropathy
Grossly thickened, lobulated folds in gastric fundus and body with poor barium coating. low albumin
CT - Massive thickening of mucosa and submucosa, giant, mass-like, tortuous folds resemble cerebral convolutions
DDx
Gastritis - thickened lobulated folds favour antrum
ZES - Multiple ulcers, pancreatic tumor (gastrinoma)
Types of gastric volvulus?
- Organoaxial
- Greater curvature flips over the lesser.
- Older people
- Associated with paraesophageal hernia - Mesenteroaxial
- Twisting over the mesentery
- ischaemia, obstruction
- kids
Whipples disease
Nodular thickening of jejunal folds
+ LOW density (near fat) mesenteric lymphadenopathy
Pseduo whipples
MAI infection in AIDS patient CD$ <100
Nodules in jejenum
+ Splenomegaly and retroperitoneal lymph nodes
small bowel adenocarcnioma
Proximal small bowel usually, Jejunum . present with SBO!!
**Increased incidence with coeliac disease
**
Focal circumferential bowel wall thickening in the proximal small bowel
DDx
Small bowel lymphoma
- immunosuppression - transplant, AIDS
- usually **do not obstruct, lumen can be aneurysmal and not narrow
**
Carcicnoid
- distal small bowel - terminal ileum and appendix
Carcinoid
spiculated mesenteric mass with calcification/ desmoplastic reaction
Tethering of SB loops
90% arise in terminal ileum/appendix
Hyper-vascular liver mets - Carcinoid syndrome
111I- Octreotide scans (1st - highest sensitivity)
or 123I-MIBG (for 10% dont take up octreotide)
for Dx and staging
Big centres use gallium PET
Assocaited with MEN 1 or MEN 2a
DDX
Sclerosing mesenteritis/ mesenteric pannicultuis
- FAT HALO sign - Mass envelop vessels, but preservation of fat around vessels
- usually jejunal small bowel mesentery
Gastrointestinal Stromal Tumor (GIST)
- Hypervascular tumor, not associated with desmoplastic effect on mesentery
Small Bowel Carcinoma
- More common in duodenum or jejunum than in ileum
- Causes luminal obstruction
- Mass and metastases are hypovascular
Desmoid tumour
Small bowel mesentery or abdominal wall mass arising at site of scarring from prior surgery
Associated with Gardner syndrome or familial adenomatous polyposis (FAP), usually intraabdominal
Soft tissue mass with well-defined or ill-defined margins
variable, heterogeneous enhancement on CECT
can infiltrate into bowel wall/adjacent structures, can cause SBO
Key difference between direct and indirect hernia?
Direct
- Medial to inferior epigastric artery
- Defect in Hesselbacks triangle
Indirect
- most common
- lateral to the inferior epigastric artery
- Covered by internal spermatic fascia
- failure of Processus vaginalis to close
Features of femoral hernia?
Old females
Medial to femoral vein
Posterior to the inguinal ligament
Usually on the right
Neutropenic Colitis (Typhlitis)
Life-threatening, necrotizing enterocolitis occurring primarily in severely neutropenic patients
Massive mural thickening of cecal ± ascending colon wa
Mucosal hyperenhancement and submucosal edema (marked)
Caecum
Pyogenic
-Singular - Klebsiella
-Multiple - E.coli
-‘Double targe sign’
-Confluent complex cystic lesions
Candida - Bulls eye
Amoebic
- ‘extra hepatic extension’ - if left lobe needs emergently drained as can rupture into the pericardium
-transient hepatic attenuation difference (THAD) due to thrombophlebitis of portal vein and hyperemia of abscess capsule
- enhancing capsule and hypodense halo of edema
Hydatid
- ‘water lily, sandstorm’
- Large, well-defined, cystic liver mass with numerous peripheral daughter cysts
- Echinococcus
Schistosomiasis is - ‘Tortoise shell’
- Septations hyperdense
Hepatic Cavernous Hemangioma
US - Hyperechoic with acoustic enhancement
CT - Hypodense (isodense to blood)
MRI - T1 low and T2 High (++ light bulb)
Enhancement - Peripheral nodular arterial enhancement (supplied by hepatic artery)
slow, progressive, centripetal enhancement isodense to vessels
> 10cm = Giant
incomplete centripetal filling of lesion (scar does not enhance)
Haemangioma vs mets
- delayed imaging and T2 haemangioma is brighter than the spleen
- So bright can cause T2 shine through on DWI
FNH
Female predominant .
2nd most common benign lesion after haemangioma
CT/ MRI
- Homogenously arterial enhancement except for central scar.
- blends in imperceptibly on the portal venous-phase
- delayed enhancement of central scar
MRI
-‘Stealth lesion’ - Isointense on t1/t2 to liver parenchyma
**Nb central scar can by hyperintense on T2
- retains gadoxetate **
Sulfur colloid hot*
Nb Small haemangioma can mimic and have rapid filling - peripheral enhanced areas though stay isodense to blood vessels
Hepatic adenoma
Female (OCP) or Man (steroids)
**Solitary
Multiple = Von Gierke
Can’t reliably differentiate from HCC on imaging.
Heterogeneous
Hyper vascular mass
+/- foci of fat or haemorrhage
Nb Signal drop out as fat
Propensity to bleed - RUQ pain is often the presentation
Doesnt retain Gad like FNH as no functioning bile ductules
HCC
Look for Liver cirrhosis
AFP elevated (90%)
Often invade the hepatic and portal vein
Arterial hyperenhancement and washout in PV or delayed phases on CT or MR
Heterogenous MR/CT depending on the degree of fatty change, fibrosis, necrosis
fibrolamellar HCC
Young and non-cirrhotic
Normal AFP
May Ca2+
**‘Central scar’ ** = Doent enhance
scar is T1/T2 dark
Gallium avid (FNH is colloid sulfur)
Heterogeneously enhancing, large, lobulated mass with hypointense central scar and radial septa
Hepatic angiomyolipoma
Well-circumscribed, mostly (sometimes variable amount) fatty mass
US hyperechoic
CT gross fat
MRI T1 and T2 hyperintense
associated with tuberous sclerosis
Cholangiocarcinoma
Elderly, male, Painless jaundice
‘Capsular retraction’
Delayed enhancement
Peripheral biliary dilatation
Encasement of the portal or hepatic veins but NO tumour thrombus
Klatskin tumour - is cholangiocarcinoma at the bifurcation of the right and left hepatic ducts.
biliary cystadenoma of liver
Solitary large, well-defined, unilocular or multiloculated cystic
Mural calcifcation
Enhancement of septa/capsule
CANT differentiate from biliary cystadenocarcinoma
Primary versus secondary haemochromatosis
Low signal on T1 and T2
loss of signal on the in phase
Increased density on CT
Primary
- Genetic, increased absoprtion of iron
- Liver and pancreas invloved
- Spleen is SPARED
Secondary
- Acquired, Chronic illness, multiple transfusions
- Liver and SPLEEN
- pancreas is spared
MSK
large hook osteophytes involving 2nd and 3rd MCP joints
Differences between HIV cholangiopathy and PSC?
The intrahepatic duct appearances are difficult to tell apart
PSC
- Extrahepatic stricture’s rarely >5mm
- Has saccular deformities of the ducts
HIV
- Focal strictures of the extrahepatic duct > 2cm and associated with papillary stenosis
which type of choledochal cyst is the most common and which type is caroli’s disease?
Type 1 - Focal dilatation of the CBD
Type 5 is Caroli’s - Intrahepatic only
Type 2 and 3 are very rare
- 2 = diverticulum of the CBD
- 3 = Choledochocele (into duodenum)
Type 4 is both intra and extrahepatic
- associated with medullary sponge kidney
Carolis disease
Intrahepatic only
Carolis disease
- ‘Central dot sign’ - portal vein branch within dilated intrahepatic duct
- associated with medullary sponge kidney, - ADPRD
Adenomymatosis
- Crystals are intraluminal (within rokitansky-aschoff sinuses)
Cholesteroloisis
- Cholesterol is within the substance of the LAMINIA PROPRIA and associated with polyps
GB wall thickening
intramural cystic spaces containing echogenic foci and comet-tail artifacts
Can be focal (typicallf fundal)
or segmental or diffuse
Focal most common @ fundus. Cant be differentiated from GB cancer.
Pancreatic Lipomatous Pseudohypertrophy
DDX
CF
shwachman-diamond syndrome
2nd most common cause of pancreatic insufficiency in children
Short stature (metaphyseal chondroplasia)
Serous cystadenoma
Grandma (older)
Heterogenous mixed density
Microcystic (honeycomb apperance)
Predilection Pancreatic head
Doesnt communicate with the pancreatic duct (IPMNs do)
20% -** classic central scar +/- Ca2+ **
Can be younger patients with VHL
Mucinous cystic neoplasm
Mother (50s)
Pre-malignant
Predilection Body and tail
No communication with the pancreatic duct (IPMN)
Unilocular + thick spetations
MacroCyctic components >2cm
can have elavated CEA levels (transform to mucinous cystadenocarcinoma)
Peripheral calcification
side branch and main branch IPMN
Side branch
- small cystic mass, typically head or uncinate process
- < 3cm, benign
- duct can be enlarged if large amounts of mucin are produced
Main branch
- **Diffuse dilatation of the main duct ** excessive mucin production and accumulation
- atrophy of the gland and Ca2+ (DDx chronic pancreatitis)
- higher malignancy risk - resection
- dilatation of the papilla, with bulging of the papilla into the duodenal lumen, secreting thick mucin = seen on ERCP
Solid Pseudopapillary Neoplasm
Womens between 10-20
Usually, Asian or black
Large at presentation - solid and cystic, heterogenous
predilection for the tail
‘Thick capsule’
Polyposis syndromes?
FAP
- Hundreds or thousands of polyps may carpet colon. - Hepatoblastomas
- desmoid tumours
Gardner
- Multiple osteomas including - skull, mandible
- poor dentation
-fibromatoses
- desmoid tumours of mesentery and anterior abdominal wall
Turcot
-** medulloblastomas + GBM**
- Thus Hx diarrhoea and seizures
Cowdens
- aka multiple hamartoma syndrome
- **Fibrocystic disease of the breast
- Breast cancer ** (occurs in up to 50%)
- dysplastic cerebellar gangliocytoma
Peutz-jeghers
- multiple hamartomatous polyps (predominantly the small intestine)
- mucocutaneous melanin pigmentation involving the mouth, fingers and toes
- increased risk of many cancers (upper GI, ovary, thyorid, testes, pancreas and breast)
Hereditary non-polyposis colorectal cancer (HNPCC) / Lynch
- 40s/50s with colorectal cancer
- 5 times more common than (FAP
- It is the most common hereditary cause of endometrial cancer
Also Cronklite-canada syndrome
- hamartous polpys in the stomach and colon,
- alopecia or nail atrophy
Coelaic disease
CT enterography: Evidence of reversed fold pattern, multifocal intussusception
Fold reverseal (jejunum like the ileum, ileum like the jejunum. Decreased number of jejunal folds and increased ileal folds
-Moulage sign - smooth tubular appearance of the jejunum
-Dilatation without fold thickness
Mesenteric lymph nodes (low density) - Fat-fluid levels
Splenic atrophy
Iron def anaemia
associated with idiopathic pulmonary hemosiderosis
Increased risk if bowel wall lymphoma
DDX
Lymphoma
- Thickened ,nodular folds
Gallbaldder polyp vs GB malignancy
see image
appearances of Regenerative and dysplastic nodules?
Regenerative nodules (iron)
- Typically, isodense on NECT unless have iron = **siderotic regenerative nodules with are HYPERDENSE **
- Typically, low on T1 and T2
- Do not enhance
Dysplastic (fat, glycoproteins)
- show early arterial uptake but the contrast DOESNT wash out on delayed phase (unlike HCC)
- T1 bright, T2 isointense/low
Differentiate from HCC
- increased T2 signal
- restricted diffusion
- Arterial enhancement and WASHOUT on multiphase postcontrast imaging
Groove pancreatitis
Form of chronic pancreatitis affecting pancreaticoduodenal groove
Curvilinear soft tissue between pancreas and duodenum
often with cystic degeneration within groove or medial wall of duodenum
Autoimmune pancreatitis
Sausage-like enlargement of pancreas (with smooth contour and loss of pancreatic lobulations).
Hypoattenuating halo or capsule around pancreas
No pancreatic duct dilatation
Lack of calcifications and fluid collections
Can be focal or diffuse
DDX
Focal AIP can difficut to differentiate from pancreatic carcinoma. MPD dilatation and atrophy in cancer
Chronic pancreatitis
Ductal dilatation and Ca2+
Extrapancreatic imaging findings
IgG4 cholangitis in 90%: May be indistinguishable from primary sclerosing cholangitis
Stricture of common bile duct (CBD) ± intrahepatic ducts with hyperenhancement of duct wall
Renal -
Round or wedge-shaped low-attenuation parenchymal lesions. Diffuse renal enlargement
Perirenal soft tissue rind (mimicking lymphoma)
Retroperitoneal fibrosis, IgG4-related lung disease, and enlarged salivary glands or salivary gland mass
Pseudomyxoma peritonei
Low-attenuation masses (usually < 20 HU) scattered throughout peritoneum
Thick walls, septa and calcificaiton
‘scalloped appearance’/displace of liver and spleen
Mucocele
Dominant cystic or solid mass often present in right lower quadrant/tip caecum (in expected location of appendix) .
+/- curvillenar calcifcation
Mucin-producing neoplasm of appendix causes appendiceal distention and subsequent perforation with diffuse intraperitoneal spread of mucinous implants
DDx
Peritoneal carcinomatous
- discrete tumour Implants are solid
-Rarely may cause “scalloping”
TB peritonitis
- Ascites and omental/mesenteric fat stranding with symmetric, smooth enhancement and thickening of peritoneal lining
-can be loculated
- look for including low-attenuation mesenteric nodes and thickening of cecum and terminal ileum
HHT
**Tortuous and prominent hepatic arterial branches **
Dilated hepatic veins and early filling
Arterial phase, mosaic attenuation of the liver with multiple enhancing foci
aka Osler-Weber-Rendu syndrome
Hereditary multiorgan disorder → fibrovascular dysplasia with development of telangiectasias and arteriovenous malformations (AVMs)
Sigmoid Vovulus
Inverted U shape
Ahaustra
Coffee bean - cleft is double thickenss of opposed bowel loops
Directed toward right upper quadrant (RUQ) or left upper quadrant (LUQ);
Look for -
Gas in proximal small bowel and colon
Abscence of air in rectum
Tend to be older patients
Mx with rectal decompression
Caecal voluvulus
Dilated, air-filled left upper quadrant or abdominal midline
Haustra
Single, long air-fluid level within cecum (upright or decubitus film)
Moderately distended small bowel, little gas in distal colon
Markedly dilated cecum that appears upside down and backward with ileocecal valve directed laterally
