Small intestine & ampulla



Editor-in-Chief: Debra L. Zynger, M.D.
Raul S. Gonzalez, M.D.

Last author update: 11 January 2021
Last staff update: 12 January 2021

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PubMed Search: Adenoma[TI] ampulla[TIAB]

Raul S. Gonzalez, M.D.
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Cite this page: Gonzalez RS. Adenoma. website. Accessed February 7th, 2023.
Definition / general
  • Dysplastic, premalignant lesion of ampulla of Vater
Essential features
ICD coding
  • ICD-10: D37.6 - Neoplasm of uncertain behavior of ampulla of Vater
Clinical features
  • Endoscopic impression, confirmed on biopsy
Case reports
  • Early or relatively confined lesions may be excised by endoscopic polypectomy or ampullectomy (Am J Clin Pathol 2009;132:506)
  • Otherwise, requires pancreatoduodenectomy
Clinical images

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Gross description
  • Polypoid / exophytic mass
Gross images

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Raised lesion at ampulla of Vater

Microscopic (histologic) description
  • Tubular, villous or mixed, similar to adenomas in colon, with approximately half tubular and half villous (Am J Clin Pathol 2009;132:506)
  • Dysplastic epithelium may have only subtle changes of mild cellular stratification and fine chromatin pattern
  • Often contain prominent Paneth cells (with coarse, large, red-pink, refractile granules in supranuclear cytoplasm), endocrine cells (dark, red-purple, fine small granules in basal cytoplasm) and goblet cells
  • May show high grade dysplasia or give rise to adenocarcinoma
Microscopic (histologic) images

Contributed by Raul S. Gonzalez, M.D.

Ampullary adenoma with low grade dysplasia

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Ampullary adenoma with high grade dysplasia

Ampullary adenoma

Cytology description
  • Endoscopic brush cytology is sensitive and specific for adenoma / carcinoma, although diagnosis of adenoma does not exclude coexisting carcinoma (Am J Clin Pathol 1998;109:540)
Cytology images

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Molecular / cytogenetics description
Sample pathology report
  • Ampulla, polypectomy:
    • Ampullary adenoma (low grade dysplasia)
Differential diagnosis
Board review style question #1
Which of the following is true about adenomas of the ampulla of Vater?

  1. BRAF mutations are rarely seen
  2. Cases must be managed with pancreatoduodenectomy
  3. Patients with Lynch syndrome are at significantly increased risk
  4. Progression to adenocarcinoma is unusual
Board review style answer #1
A. BRAF mutations are rarely seen. KRAS and APC mutations are more common, both in sporadic cases and in those from patients with familial adenomatous polyposis.

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Reference: Adenoma
Board review style question #2
A polypoid lesion of the ampulla is biopsied and shows the features below. Which of the following molecular mutations is most likely to be present?

  1. BRAF
  2. KRAS
  3. MLH1
  4. STK11
Board review style answer #2
B. KRAS mutations are most commonly seen in ampullary adenomas, along with APC mutations.

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Reference: Adenoma
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