Small intestine & ampulla
Benign tumors / tumor-like conditions
Hyperplastic polyp

Topic Completed: 8 January 2019

Minor changes: 19 November 2020

Copyright: 2003-2020,, Inc.

PubMed Search: Hyperplastic polyp small bowel "loattrfree full text"[sb]

Raul S. Gonzalez, M.D.
Page views in 2019: 5,459
Page views in 2020 to date: 5,617
Cite this page: Gonzalez RS. Hyperplastic polyp. website. Accessed December 4th, 2020.
Definition / general
  • Nonmalignant hyperplastic proliferation of small intestine
Essential features
  • Extremely rare benign duodenal / ampullary polyp
  • Resembles microvesicular hyperplastic polyp microscopically
ICD coding
  • ICD-10: D13.2 - benign neoplasm of duodenum
  • Hyperplastic polyps are extremely rare anywhere in the duodenum
  • Occurs in second part of duodenum and ampulla
  • Uncertain malignant potential
Clinical features
  • Mean age 52 years
  • Usually incidentally detected
Case reports
Microscopic (histologic) description
  • Similar to microvesicular hyperplastic polyp of the colorectum, with elongated crypts, superficial serration and decreased goblet cells (Hum Pathol 2011;42:1953)
  • No evidence of basal crypt booting (as in sessile serrated adenoma of the colorectum) or gastric foveolar metaplasia
Microscopic (histologic) images

Images hosted on other servers:

Duodenal hyperplastic polyp

Positive stains
  • Epithelial cells express MUC2 (focal), MUC5AC and MUC6 (crypt bases)
Molecular / cytogenetics description
  • May harbor KRAS or BRAF mutations
Differential diagnosis
Board review style question #1
Hyperplastic polyps of the small intestine most resemble which type of colorectal polyp microscopically?

  1. Goblet cell rich hyperplastic polyp
  2. Microvesicular hyperplastic polyp
  3. Mucin poor hyperplastic polyp
  4. Sessile serrated adenoma
Board review answer #1
B. Microvesicular hyperplastic polyp

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Board review style question #2
This polyp was resected from the duodenum. Which of the following is true?

  1. Deeper levels would show conventional cytologic dysplasia
  2. These polyps are extremely rare in the small intestine
  3. This must be a traditional serrated adenoma, despite the lack of abundant eosinophilic cytoplasm
  4. This patient must have serrated polyposis syndrome
Board review answer #2
B. These polyps are extremely rare in the small intestine. This is a hyperplastic polyp; duodenal examples resemble colonic microvesicular hyperplastic polyps.

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