Melanoma in Sinclair swine: a new animal model.

A new animal model for the study of melanocytic tumors is presented. A strain of miniature swine, bred for small size, has genetically determined tumors similar to many types of human pigment tumors, from benign junctional nevi to bizarre metastatic melanomas. Some tumors regress spontaneously and this regression may be accompanied by a generalized depigmentation of the animal with a predilection for many of the same anatomic areas involved in human vitiligo. These animals are ideal for study of the interrelationships of senescence, actinic exposure, and other factors in malignant degeneration, as well as the role of immunity and growth control factors in regression and regulation of tumor growth.