["Keratoacanthomas" in mastomys natalensis (author's transl)]

54 Tumors of Mastomys natalensis (GRA Giessen), described in the literature as "Keratoacanthomas" were investigated by light and electron microscopy. They are induced by a virus of the Papova group. Their histogenesis and their course are very different from human keratoacanthoma. The results reveal problems related to experimental animal tumour models and the similarities of different malignancies in the nomenclatures of several disciplines.