Hyperplastic polyps show crypt elongation with a serrated hyperplastic outline. The serrations are usually more prominent in the upper half of the crypts.
The infoldings of the epithelium create a serrated profile -- numerous mature goblet cells and absorptive cells are seen.
This rectal hyperplastic polyp shows some different alterations.
The basse shows irregular wisps of smooth muscle and some glandular architectural disarray. Hemosiderin is also found.
Muscle fibers percolate into the lamina propria, indicating this polyp has some secondary prolapse change. One should not mistake this for a sessile serrated polyp.
Non-neoplastic polyps are the GI tract include the hyperplastic polyp (most common), hamartomatous polyp, inflammatory polyp and lymphoid polyp. Hyperplastic polyps are believed to form from decreased epithelial cell turnover and subsequent accumulation of mature epithelial cells on the surface of the glands. The delayed shedding and retention of epithelial cells leads to infoldings crypts. The profile of the crypts appear serrated and irregular and when seen en face, the lining of the tubules appear star-like.
The nuclei of epithelial cells may be hyperchromatic at the bases with prominent nucleoli. Mild atypia may be present, but there should not be obvious dysplastic changes such as prominent crowding, loss of polarity or obvious pleomorphism.
Can arise at any age, but usually incidentally discovered during colonscopy or sigmoidoscopy. Grossly, these polyps are dome-shaped and rarely exceed 5mm in diameter. They are often multiple and over half are identified in the rectosigmoid.
Although larger hyperplastic polyps can be seen in conjunction with adenomatous polyps, the usual small hyperplastic polyp is not considered to have malignant potential. Excision is curative.
1 Kumar V, Abbas AK, Fausto N. Robbins and Cotran Pathologic Basis of Disease. 7th Ed. Philadelphia, PA: Elsevier; 2005: 858.
2 Iacobuzio-Donahue CA, Montgomery EA. Gastrointestinal and Liver Pathology: Foundations in Diagnostic Pathology. Philadelphia, PA: Elsevier; 2005: 367-9.