gastrointestinal amyloidosis
Gastrointestinal amyloidosis is relatively common, although symptomatic involvement is more rare. It is diagnosed if there are persistent gastrointestinal (GI) symptoms with endoscopic biopsy proven amyloid deposition.
Epidemiology
Tends to affect middle-aged and older patients.
Clinical presentation
Weight loss (most common) and GI bleeding are the main symptoms. Other symptoms include gastro-esophageal reflux, constipation, nausea, diarrhea, weight loss, early satiety, and abdominal pain.
Pathology
Bowel changes result from amyloid infiltration of the muscularis and destruction of Auerbach plexus.
Location
- duodenum (most common)
- stomach (second most common): the gastric manifestations of amyloidosis include gastric fold and or wall thickening and rigidity. Luminal narrowing can cause a linitis plastica type appearance and mimic gastric carcinoma.
- colon and rectum
- esophagus
Radiographic features
Radiological findings are rare and non-specific, unlike the pathologic high specificity.
Fluoroscopy
On fluoroscopy, the gastric mucosa may display thickened folds, which may appear nodular or mass-like and which may contain calcifications.
CT
Features include:
- diffuse wall thickening of the involved segment of bowel
- intussusception
- dilatation depending upon the degree of hypomotility; GI bleeding can also cause dilated bowel loops with fluid levels
- luminal narrowing either due to amyloid infiltration or secondary to ischemia
Differential diagnosis
- infectious enteritis (e.g. Shigella, Salmonella, Escherichia coli, cytomegalovirus, Cryptococcus, pseudomembranous colitis, AIDS)
- bowel ischemia
- other infiltrating processes, e.g. small bowel lymphoma
- other causes of GI bleeding