Melanoma induction in a hairless mouse with short-term application of dimethylbenz[a]anthracene

Melanomas have been induced in hamsters and guinea pigs with short-term, lo w dose applications of dimethylbenz [a]anthracene (DMBA) alone. In mice, ho wever, melanoma induction has required either croton oil or ultraviolet rad iation promotion in addition to DMBA. In this study, we report the developm ent of a malignant melanoma, with metastases, in a hairless mouse after six applications of 0.25% DMBA alone. At sacrifice, a large primary tumour wit h characteristics of intralesional transformation was present, along with n umerous pigmented macules and papules. Metastases were present in lymph nod es and lungs. There was a marked similarity between this melanoma and its p recursor lesions and those seen in an earlier, Weiser-Maple guinea pig mode l, which, in turn, resembled human melanoma. (C) 2001 Lippincott Williams & Wilkins.