From the Guidelines
Hyperplastic polyps of the colon are generally considered benign lesions, not malignant, with very low or no malignant potential, as stated in the guidelines by the US Multi-Society Task Force on Colorectal Cancer and the American Cancer Society 1.
Characteristics of Hyperplastic Polyps
- Typically small (less than 5mm), pale, and sessile (flat) growths
- Develop from excessive cell proliferation in the lining of the colon
- Unlike adenomatous polyps, which have a clear progression to colorectal cancer, hyperplastic polyps are not considered precancerous in most cases
Exceptions and Special Considerations
- Large hyperplastic polyps (greater than 1cm) located in the right side of the colon, or those associated with serrated polyposis syndrome, may have some malignant potential 1
- Hyperplastic polyposis, defined by the presence of multiple hyperplastic polyps, may also increase the risk of colorectal cancer, although the magnitude of this risk is not yet fully understood 1
Clinical Management
- During colonoscopy, gastroenterologists typically remove all polyps regardless of their appearance, as visual inspection alone cannot definitively distinguish between hyperplastic and adenomatous polyps
- The final determination of a polyp's nature is made through histological examination by a pathologist after removal
- Patients with small distally located hyperplastic polyps should be rescreened as appropriate for average-risk patients, while those with large or proximally located polyps, or those with hyperplastic polyposis, may require more frequent surveillance or other management strategies 1
From the Research
Hyperplastic Polyp Classification
- Hyperplastic polyps are generally considered to be benign lesions, but recent studies have suggested that some may have malignant potential 2, 3.
- A study from 2015 reclassified hyperplastic polyps into traditional hyperplastic polyps (THP), sessile serrated lesions (SSL), and other lesions, and found that 16% of patients with SSL subsequently developed a neoplastic lesion 2.
- Another study from 2002 found that risk factors for hyperplastic and adenomatous polyps were similar to those for colorectal cancer, and suggested that some hyperplastic polyps may have neoplastic potential 3.
Relationship to Colorectal Cancer
- A study from 1988 found that patients with hyperplastic polyps were more likely to have adenomas, and that patients with rectosigmoid hyperplastic polyps were more likely to have proximal adenomas 4.
- A study from 2011 found that the use of nonsteroidal anti-inflammatory drugs (NSAIDs) was associated with a reduced risk of adenomatous polyps, and that baby aspirin was also associated with a reduced risk of hyperplastic polyps 5.
- A case study from 2012 found that chronic use of aspirin and NSAIDs may have delayed the appearance of adenomas in a patient with attenuated intestinal polyposis 6.
Malignant Potential
- While hyperplastic polyps are generally considered benign, some studies have suggested that they may have malignant potential, particularly in certain subtypes such as SSL 2, 3.
- The malignant potential of hyperplastic polyps is still a topic of debate, and further studies are needed to clarify the cancer risk of these lesions 2, 3.