Spontaneous adenocarcinoma of the ascending colon in Wistar rats: the intracytoplasmic presence of a Campylobacter-like bacterium.

Campylobacter-like bacteria were demonstrated in the neoplastic cells in 15 of 17 naturally occurring endophytic adenocarcinomas of the ascending colon in Wistar rats. These bacteria were also present in the cytoplasm in metastases in the regional lymph nodes. The microorganisms penetrated the epithelial layer and their presence was associated with a chronic productive inflammatory reaction. A possible causal association of Campylobacter-like organisms in carcinoma of the colon in man and in the Wistar rat is discussed.