Pigmented nonmelanoma skin cancers of the genital area: a diagnostic and therapeutic challenge – monocentric experience and review of the literature

Nonmelanoma skin cancers (NMSC), comprising basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), are typically encountered on photo-exposed skin. Nevertheless, several cases of NMSC have been described in covered areas such as the genital region; furthermore, some of these lesions may express a variable degree of pigmentation. Due to the existence of mucosal melanoma, an accurate diagnosis is paramount. In this narrative review, we focused our attention on management and – in particular- diagnosis of pigmented NMSC (pNMSC) located in the genital region, emphasizing the features assessed by dermoscopy and reflectance confocal microscopy. As an implementation, we included data on pNMSC from the Dermatology Unit of the University of Campania Vanvitelli. BCC in the genital region represents only 1% of all BCC cases. It has been supposed that the mutation of patched 1 may lead to the development of BCC even without concomitant UV exposure. Pigmented variants on genitals have seldom been described. More prominent dermoscopic features seem to be blue-gray ovoid nests and arborizing vessels associated with whitish structureless areas. SCC and Bowen's disease (BD) – a variant of in situ SCC – may be encountered in the genital area and are sometimes associated with human papillomavirus (HPV) infection. Pigmented SCC is very rare, and most of the literature is focused on pigmented BD (pBD), which is mainly characterized by gray-brown dots in a linear fashion and glomerular vessels without evident scales. In conclusion, pNMSC is rarely encountered on genitals; evaluation with dermoscopy or other ancillary devices like RCM is important both to exclude benign lesions like seborrheic keratosis and lentigo and to rule out melanoma.