Figure 2. The Apc^Min mutation alters the histopathology of MMTV-PyMT mammary tumors and enhances tumor volume.

Tumors were fixed, embedded and stained with H&E. Quantification of the histopathological classification demonstrates that more tumors from MMTV-PyMT;Apc^Min/+ (n = 9) mice display a squamous adenocarcinoma phenotype rather than solid carcinomas in control animals (n = 7) (A, p<0.05 using Fishers exact test). Representative images of H&E-stained MMTV-PyMT;Apc^+/+ tumors showing development of solid carcinomas (B). In contrast, tumors from the MMTV-PyMT;Apc^Min/+ mice were predominately classified as squamous adenocarcinomas (C). Scale bar = 100 µm. (D) At 65 days of age, there was an increase in the number of MMTV-PyMT;Apc^Min/+ (n = 21) mice with a greater total tumor volume than the mean of the control animals (n = 18) (p<0.05 using exact binomial test goodness-of-fit).