Relation between animal-type melanoma and reduced nuclear expression of glutathione S-transferase pi

Animal-type melanoma (ATM) is a rare variant of the tumor showing diffuse, heavily pigmented neoplastic cells in the dermis. Despite the high mean thickness of the lesions, reports seem to indicate a less aggressive behavior and a better survival rate for ATM compared with conventional melanoma, but the underlying pathways related to this favorable outcome are still unknown.