Reply to the commentary on 'Oral melanoma and other pigmentations: when to biopsy?'

Cutaneous and Mucosal Melanomas of Uncommon Sites: Where Do We Stand Now?

Melanomas arising at uncommon sites include a group of lesions related to unusual localizations in specific ethnic groups. The rarity of the disease often represents a limit to the participation of patients in specific trials. However, this peculiar genetic scenario has important therapeutic implications regarding new oncologic therapies. The aim of this article is to review the clinical features, somatic alterations and therapeutic options for melanomas of uncommon sites. They can be classified as cutaneous and mucosal lesions affecting the nail apparatus, palms/soles, oral mucosa, genital area and scalp. The prognosis may be worse compared to melanomas of other districts, and a prompt diagnosis may dramatically influence the outcome. Dermatologists and oncologists should therefore distinguish this melanoma subgroup in terms of surgical intervention and medical treatment. Due to the lack of mutations in genes usually found in cutaneous melanomas, the discovery of novel targets is required to develop new strategies and to change the prognosis of non-responders or wild-type patients.

Oral and nail pigmentations: a useful parallelism for the clinician

Oral (OP) and nail (NP) pigmentations may occur simultaneously in physiological or pathological conditions, and may be a sign of underlying syndromic conditions that necessitate further investigation and treatment. Interestingly, the nail unit and oral cavity show a clinical parallelism that may help the clinician to conduct a correct examination and reach a prompt diagnosis. Both OP and NP can manifest clinically with focal or diffuse involvement and are due to external factors (exogenous pigmentation, drug-induced pigmentation) or endogenous factors (racial pigmentation, post-inflammatory pigmentation, nevi, genetic conditions and other disorders). The most concerning differential diagnosis is melanoma. Here we report the pathogenetic basis of OP and NP, together with the description of similar clinical features. To the best of our knowledge this is the first paper to summarize and describe the causes of pigmentation of both the oral cavity and the nail unit.