Experimental induction of preneoplastic and neoplastic changes in the lingual mucosa of rats.

Squamous cell carcinomas of the tongue can be produced reliably in rats by repeated application of the carcinogen 4-nitroquinoline-1-oxide. The histopathological changes in the lingual epithelium during carcinogenesis were progressive, passing through mild to moderate to severe epithelial atypia before the development of squamous cell carcinoma. Initiation, with its putative irreversible cellular changes, occurred within 4 weeks.