Duodenal Filling Defects

Small

• Lymphoid hyperplasia: Multiple Little (1 mm - 2 mm) filling defects. May be normal in children. May be associated with giardiasis in adults with hypogammaglobunimeia.
• Heterotopic gastric mucosa: Multiple mini (few mm) filling defects clustered in a mosaic pattern.

Large

• Pancreatic rest: Ectopic pancreatic tissue. Smooth (round or lobulated) filling defects 1 cm - 2 cm in diameter. Classical appearance of a central dimple of barium that can be confused with an ulcer. Usually found in the bulb or descending duodenum.
• Brunner gland hyperplasia: Multiple, Big (up to 1 cm or so), rounded filling defects at the bulb that can extend to the descending duodenum. Often produce a cobble stone appearance.

Miscellaneous/Uncommon

• Flexural pseudopolyp: Usually in thin patients. Due to sharp angle between the apex of the duodenal bulb and the descending duodenum, which causes mucosa to bunch up at the apex of the bulb.
• Adenoma: Uncommon. Mucosal polypoid lesions with high potential for malignant degeneration. Usually smaller than 1 cm. Villous adenomas can get larger than 1 cm and are more likely to be found in the periampullary region.
• Mesenchymal tumors: Leiomyoma or lipoma. Most common benign lesions of duodenum. Smooth, submucosal lesions. Ulceration uncommon.
• Kaposi: Multiple polypoid and ulcerated lesions.
• Carcinoid: Typically in the descending duodenum, peripapillary region.
• Choledochocele: Causes extrinsic compression.
• Papillitis: Enlarged major papilla due to inflammation, usually recent passage of a calculus.