Guidelines for Diagnosis of the Lynch Syndrome

The Lynch syndrome is the most common inherited syndrome associated with colorectal cancer, accounting for 3% of new diagnoses; it is also associated with extracolonic cancers, the most common of which is endometrial cancer.
The Lynch syndrome phenotype includes a propensity for cancers of the proximal colon, poor tumor differentiation with mucinous or signet-ring cell histologic features or a medullary growth pattern, abundant infiltrating lymphocytes in the tumor, and synchronous and metachronous colorectal cancers. Continue reading

Revised Criteria for Hereditary Non-Polyposis Colorectal Cancer (Lynch Syndrome)

Amsterdam Criteria (1991)

Three or more relatives with colorectal cancer, plus all of the following:

  • One affected patient should be a first-degree relative of the other two;

  • Colorectal cancer should involve at least two generations;

  • At least one case of colorectal cancer should have been diagnosed before the age of 50 years.

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