Naturally occurring intestinal epithelial neoplasms in aged Crl:CD BR rats

Abstract

Spontaneous primary epithelial neoplasms of the intestinal tract occurred in 6/682 (0.9%) male and 1/694 (0.1%) female Sprague-Dawley rats. Six of 7 neoplasms were adenocarcinomas, and 1 of 7 was an adenoma. Metastasis to the liver or lung occurred in 3 of the rats with adenocarcinoma. These findings are consistent with those reported for female Sprague-Dawley rats and for males and females of other strains over the past 25 years. The intestinal neoplasm incidence in males exceeded that reported for other Sprague-Dawley males with one exception, reported 30 years ago.