Table 1 Comparison of 2010 and 2019 WHO Criteria for Serrated Polyposis Syndrome (SPS)

Type 1

I. At least 5 serrated polyps proximal to the sigmoid Colon, 2 of which are > 10 mm in diameter.^α

I. ≥5 Serrated lesions/polyps proximal to the rectum, all being ≥5 mm in size, with at least 2 being ≥10 mm in size

II. Any number of serrated polyps occurring proximal to the sigmoid Colon in an individual who has a first-degree relative with SPS.

Type 2

III. > 20 serrated polyps of any size distributed throughout the Colon.^α

II. > 20 Serrated lesions/polyps of any size distributed throughout the large bowel, with ≥5 being proximal to the rectum.