Prevalent Location of Flat Dysplastic Aberrant Crypt Foci near Lymphoid Follicles in the Colon of Azoxymethane-treated Rats

Abstract

In the colon of F344 rats treated with 2 × 15 mg/kg body weight of azoxymethane (AOM), the density (number of lesions/cm²/rat) of flat aberrant crypt foci (ACF) was 13-fold higher (p<0.05) in the surface area of mucosa immediately adjacent to lymphoid follicles compared with the density of these lesions in the rest of the mucosa. A similar prevalent location near lymphoid follicles was observed for tumours, but not for the classic elevated ACF. The lymphoid follicle-associated flat ACF had the same characteristics as those located in the rest of the mucosa: i.e. severe dysplasia and Wnt pathway stimulation.