multiple colorectal adenomas
Saturday 1 December 2012
The presence of multiple colorectal adenomas (5–100) may be explained by either attenuated FAP or attenuated MAP.
However, most affected subjects will have neither APC nor MUTYH germline mutations.
Multiple colorectal adenomas have been described in patients with acromegaly, hereditary mixed polyposis syndrome, and Bloom’s syndrome.
Three independent studies have identified an adenoma susceptibility locus on chromosome 9q22.32.
Most patients with Lynch syndrome or hereditary non-polyposis colorectal cancer have fewer than five adenomas, but exceptions will occur.
At endoscopy or when examining a surgical specimen with multiple polyps, it is advisable to sample a subset of the smaller polyps to exclude a diagnosis of hyperplastic polyposis.
Most examples of multiple adenomas appear to represent the high end of the range of sporadic adenomas, although this does not preclude an underlying genetic explanation.
familial adenomatous polyposis
- classical familial adenomatous polyposis (classical FAP)
- attenuated familial adenomatous polyposis (attenuated FAP)