Adenomatous polyps (AP) of the gastrointestinal tract in children are very rare. Because of their potential
malignancy, they are of great clinical importance. There is little experience in the management of children with AP. The immunohistochemical expression of the
Lewis blood group antigens (BGA) (sialosyl-Le(a), Le(a), Leb, Le(x), and Le(y)) and the number of activated nucleoli with the
silver staining method for nucleolar organizer regions (
AgNORs) were studied in two children with AP. In a girl with isolated AP of the stomach and colon, it was found that
antigens Le(b) and s-Le(a) were expressed extensively in the gastric
adenoma, and sialosyl-Le(a) throughout the entire length of the rectal
adenoma crypts, but in the
AgNORs stain the number of nucleoli ranged from two to four, evidencing changes of a benign character. In the case of
familial adenomatous polyposis diagnosed in a 9-year-old boy, in some colonic
adenomas the number of activated nucleoli was greater than five, and the
Le(b) antigen was expressed in superficial epithelial cells in one of the
adenomas. Also, extensive expression of
antigens Le(y) and s-Le(a) throughout the entire length of the crypt in another
polyp removed was observed. We believe that immunohistochemical study of the intensity and extent of the expression of Lewis BGA in the
polyp tissue simultaneously with the determination of the number of activated nucleoli by the
AgNORs staining method can be helpful in better analysis of cytological risk factors of a malignant transformation.