SPONTANEOUS MELANOMA IN REGENERATING TAILS OF AXOLOTLS.

Abstract

AbstractRelationships between neoplasia and regeneration were studied in the regenerative processes following 21 amputations through or near 8 spontaneous melanotic formations in the tails of axolotls. It was found that spontaneous melanoma can grow in the presence of regeneration, but that melanotic ingrowth into a regenerate tends to be limited to temporary “symbiotic” participation of the melanotic tissue in the development of the regenerate. It was also found that regeneration is almost always essentially normal in the presence of a spontaneous melanoma, even when the regenerate grows from the tumor itself or from a previous regenerate that is black with melanotic cells.Melanotic cells are presumably derived from normal pigment cells, and some investigators have suggested that neoplastic cells under the influence of regenerative processes may occasionally be transformed back into normal cells. The present study has provided no evidence that such a transformation ever occurs. Instead, the regenerative processes seem only to limit the neoplastic activity of melanotic cells that participate in regenerative growth. In fact, when regeneration is abnormal, melanotic cells may behave much as they do in the absence of regeneration.