Macular-appearing Nodular melanoma Arising from a Preexisting Melanocytic nevus in an Elderly patient--Can “Older Age of Nevus” be Besponsible for Unusual Morphogenesis and Melanomagenesis?

Abstract

Malignant melanoma (MM) is the most serious skin tumor whose classical clinical types include lentigo maligna (LM), superficial spreading melanoma (SSM), nodular (NM), and acral lentiginous melanoma (ALM). Clinical appearance of a MM may not always be compatible with its histological type, and sometimes it may express itself with an unusual appearance. We report a 80-year-old man with a NM having a macular appearance, which arose from an acquired melanocytic nevus. The lesion of our patient resembled an SSM clinically, but its histopathological examination proved a NM. Such macular appearance of a NM is an unusual condition. Our case was presented to draw attention to both the misleading macular appearance of the NM, and its unusual nonhierarchical development.