GI Flashcards
Causes of linitis plastica
Imaging appearances
#1 Scirrhous adenoCa stomach #2 Lymphoma - often thicker >4 cm #3 Mets (usually breast and lung)
Rigid wall of stomach with reduced distension and altered fold pattern; ddx = gastritis from other causes (eosinophilic, TB, corrosive ingestion)
What entity causes Rams horn sign?
- Crohn disease
- Causes tubular/conical appearance of distal stomach and antrum
Imaging appearances in GVHD
When does this occur?
- 100 days post BMT, after induction chemo or radiation
- Most commonly SB and colon
- Mural and fold thickening progressing to ribbon like bowel, separated loops (on upper GI)
- Segmental involvement
Imaging findings celiac disease
Barium
- small intestinal dilatation
- intussusceptions
- jejunoileal fold pattern reversal
- moulage sign (loss of normal folds)
CT (similar findings)
- reversal of folds
- ileal fold thickening
- prominent nodes - can contain fat/cavitate
- splenic atrophy
- *increased risk of adenocarcinoma and lymphoma of SB
Ddx for nodular, thickened small bowel folds
Whipples - sand-like nodules in the jejunum, thickened folds, big low attenuation nodes
MAI (pseudo Whipples) - segmental or diffuse small bowel wall thickening + big nodes
DDx: lymphoma
Most common location of TB in GI tract
Terminal ileum
C-RADS findings and F/U
C0: inadequate study
C1: normal colon/benign lesion: routine screening to be continued
C2: indeterminate polyp: surveillance or colonoscopy
- 6-9 mm in diameter
<3 in number
C3: possibly advanced adenoma: follow up colonoscopy
>10 mm in diameter
>3 in number with each 6-9 mm
C4: colonic mass likely malignant: urgent surgical referral
has associated luminal narrowing
has extra-colonic extension
Which rectal cancer nodes are local versus mets? What are concerning features?
Local - mesorectal, sup/mid/inf rectal, int iliac, sacral, sigmoidal mesentery
Concerning features: size not very reliable; consider morphology - round, irregular or heterogeneous signal
Which stages are locally advanced in rectal ca?
T3c-d, T4, N1 and N2 - require neoadjuvant chemo
Standard surgical tx for rectal Ca
TME
Where do Barrett’s esophagus strictures occur?
More commonly lower esophagus, if you see stricture in mid esophagus then Barrett’s is #1 cause
(ddx: caustic ingestion, radiation changes, drugs, etc)
Associated with pseudodiverticulosis
Ddx for enhancing lesion in the small bowel
- Carcinoid (usually TI)
- AdenoCA (ampulla or jejunum, varied appearance from polypoid to infiltrating mass)
- Mets (most common SB neoplasms, usu multiple)
- GIST (can be polypoid, central hypoattenuation)
- Lymphoma (usu ileum)
Imaging findings scleroderma
Esophagus most commonly involved (dilated)
Small bowel also has findings:
– hidebound bowel (multiple thin folds, stack of coins)
– SB dilation, usu duodenum
– pseudosacculations/pseudodiverticula
– benign pneumatosis or pneumoperitoneum
Causes of pneumatosis
- AMI #1
- Severe infx (yersinia, TB, amebiasis, etc.)
- COPD/ lung disease
- Drugs
- CTD - scleroderma
Causes of toxic megacolon
- UC (most common, look for pseudo-polyps and thumbprinting on x-ray)
- Ischemic colitis
- Pseudomembranous colitis
Other less common causes: Crohns, infection (TB)
Upper GI findings in esophageal candida
- Shaggy esophagus
- Irregular mucosal nodules
- Linear plaques
** in immunocompromised patients
Imaging features of GIST
Can occur anywhere along the GI tract, mesentery, omentum or retroperitoneum
**70% in stomach
Variable appearance - usu exophytic or in the wall of the bowel, occasionally endoluminal
Can be complicated by hemorrhage, necrosis
Generally don’t have nodal mets!! (can have mets to liver and peritoneum)
Most common location SB adenoma? AdenoCa?
Adenoma: ileum>jejunum>duodenum
AdenoCa: periampullary region
DDx for esophageal mass (malignant)
Location is key:
Lower - barrett’s - adenoCa
Upper - smoker/drinker - SCC (*other RFs: caustic stricture, achalasia, celiac)
Other rare malignant : spindle cell carcinoma (polypoid, fills lumen but usually doesn’t obstruct)
Most common benign tumour of the esophagus
1) Leiomyoma
- ovoid, well circumscribed, calcs pathognomonic
2) Fibrovascular polyp
- cervical esophagus, has fat
3) Inflammatory polys
Where do the following occur?
- feline esophagus
- peptic stricture
- esophageal web
- schatzki ring
1) Feline: Distal 2/3 esophagus, transient, associated with reflux ? candidiasis
2) Peptic: Lower esophagus (around GE junction), thicker
3) Web: cervical esophagus
4) Schatzki: b-line, above hiatal hernia at GE junction
