Histogenesis of tubular adenomas in hereditary colonic adenomatous polyposis.

Tubular adenomas were studied morphometrically and histopathologically in colectomy specimens from seven children and five young adults with hereditary colonic adenomatous polyposis. In each age group and in each patient, the diameter and height of adenomas showed a log normal distribution. Both variables differed significantly among patients in each age group and also between the two age groups. In the young adults, there was a selective growth of certain adenomas. Scatter diagrams of the diameter vs height of adenomas showed that adenomas grew preferentially in the horizontal plane in early development, giving adenomas a discoid shape. Adenomas greater than 8 mm in diameter grew both horizontally and vertically. The horizontal growth was due to division of adenomatous crypts, and adenomas greater than 8 mm in diameter also exhibited elongation of crypts.