Non-immunological regression of dimethylbenz(A) anthracene-induced experimental keratoacanthomas in the rabbit.

In 9 rabbits, with a total of 17 experimental keratoacanthomas, a search has been made for immune-mediated mechanisms which could possibly be involved in the spontaneous regression of these tumours. Immunofluorescence studies did not reveal significant staining patterns. With skin tests, using autologous extracts prepared in three different ways, no delayed cutaneous hypersensitivity reactions were observed.