Proliferative lesions of the spleen in male F344 rats fed diets containing P-chloroaniline.

Fifty male F344 rats were given diets containing 500 mg/kg P-chloroaniline. Controls received diets without the chemical. Eighteen of the dosed rats developed proliferative lesions of the spleen. Lesions included parenchymal fibrosis and fatty infiltration, well and poorly differentiated fibrosarcomas, osteosarcomas and hemangiosarcomas. All dosed rats had focal and diffuse fibrosis and papillary hyperplasia of the splenic capsule.