More than just acral melanoma: the controversies of defining the disease

Abstract

Acral melanoma (AM) is a malignant cutaneous melanocytic tumour specifically located on the palms, soles, and nail apparatus, which are areas of glabrous (hairless) skin. Acral lentiginous melanoma, a subtype of AM, represents a histopathological subtype diagnosis of cutaneous melanoma with unique morphological and structural features. Despite clear definitions, the misuse of these terms and the inconsistency in reporting the histopathological features of AM cases have become a major obstacle to the study of the disease. In this review, we discuss the epidemiology, histopathological features, prognosis, and genetic profile of AM, highlighting the differences observed when histopathological subtypes are considered. The increasing global effort to characterise AM cases from ethnically diverse populations would benefit greatly from a more consistent classification of the disease.

Cutaneous and acral melanoma cross-OMICs reveals prognostic cancer drivers associated with pathobiology and ultraviolet exposure

“…However, there are types of melanoma that arise in body parts protected from direct UV light, and these are acral, mucosal and uveal melanomas. These types represent uncommon cancers, among which the most frequent is the acral melanoma, which occurs on the glabrous skin (the skin of palms of the hands and the soles of the feet) and the subungual area 6 , 7 . Even though it is rare in the general population, acral melanoma is the most common melanoma among people with darker skin 8 .…”

Solar Ultraviolet Radiation, Skin Cancer and Photoprotective Strategies in South Africa†

“…In the White population, the tumors are commonly the superficial spreading subtype occurring on sun-exposed body sites, frequently affecting the trunk in males and the legs in females. Only 3% of CMs are the acral subtype in White patients as reported in several countries (26). In contrast to the Black African population, CMs are rarely located on the head, neck or trunk, and are more likely to be the acral lentiginous subtype affecting the soles of the foot, palms and subungual body sites.…”

A European Multicentric Investigation of Atypical Melanocytic Skin Lesions of Palms and Soles: The iDScore-PalmoPlantar Database

“…Acral-pigmented lesions are still less investigated by dermoscopy than facial or body-pigmented lesions, and the referring terminology is otherwise rather confused [ 1 , 2 , 3 , 4 , 5 ]. To date, the term “acral” has been used to define melanocytic lesions localized not only on volar glabrous skin surfaces of the extremities but also on the nail apparatus and subungual region—especially in reference to acral lentiginous melanoma (MM) [ 1 , 2 , 3 , 4 , 5 ].…”