More common are hamartomas or hyperplasia of Brunner glands
• Submucosal (intramural) lesions
• Duodenal GI stromal tumor (GIST)
Soft tissue density mass that deforms lumen
Lesions ≥ 2 cm often have central necrosis
• Duodenal lipoma
Characteristic fat density on CT
• Other mesenchymal tumors (rare)
• Carcinoid tumor
Single or multiple; may ulcerate → “target” lesions
TOP DIFFERENTIAL DIAGNOSES
• Brunner gland hyperplasia
• Duodenal flexure pseudotumor
• Ectopic gastric mucosa
• Duodenal carcinoma
• Intestinal metastases and lymphoma
• Duodenal hematoma
• Kaposi sarcoma
• Ampullary carcinoma
DIAGNOSTIC CHECKLIST
• Check for family history of GI tract polyps
e.g., familial polyposis or Peutz-Jeghers
• Lipomas can be diagnosed with confidence on CT
• Most other polyps have nonspecific imaging features
(Left) Spot film from upper GI series shows a large adenomatous polyp as a radiolucent filling defect within the duodenum.
(Right) Spot film from an upper GI series demonstrates a polypoid mass within the duodenal bulb. Endoscopic biopsy and resection revealed a hamartoma of the Brunner gland. Brunner gland hamartomas (hyperplasia) are usually multiple, smaller lesions. Larger, isolated lesions, as in this case, are indistinguishable from many other duodenal masses and require biopsy.
(Left) Axial CECT in a middle-aged man with vague abdominal pain shows a subtle heterogeneous mass within the lumen of the 2nd part of the duodenum without signs of luminal obstruction. There was also no biliary or pancreatic ductal obstruction.
(Right) Gross pathology in the same case shows the mass previously identified on CT. After endoscopic confirmation of a villous tumor at this location, a pancreaticoduodenectomy (Whipple procedure) was performed.
TERMINOLOGY
Definitions
• Protruding, space-occupying masses within duodenum
IMAGING
General Features
• Best diagnostic clue
Radiolucent filling defects, ring shadows, or contour defect on barium study
CT signs of intraluminal &/or intramural mass
• Size
Adenomatous and hamartomatous polyps: Several mm to 2 cm
• Morphology
Epithelial polyps (mucosal lesions)
Adenomatous polyps (most common)
– Usually single, lobulated or cauliflower-like surface
as a radiolucent filling defect within the duodenum.
within the duodenal bulb. Endoscopic biopsy and resection revealed a hamartoma of the Brunner gland. Brunner gland hamartomas (hyperplasia) are usually multiple, smaller lesions. Larger, isolated lesions, as in this case, are indistinguishable from many other duodenal masses and require biopsy.
within the lumen of the 2nd part of the duodenum without signs of luminal obstruction. There was also no biliary or pancreatic ductal obstruction.
previously identified on CT. After endoscopic confirmation of a villous tumor at this location, a pancreaticoduodenectomy (Whipple procedure) was performed.
Adenomatous polyps
Hyperplastic polyps
