Nail melanoma in situ: clinical, dermoscopic, pathologic clues, and steps for minimally invasive treatment

Abstract

Background: Nail unit melanoma (NUM) is a variant of acral lentiginous melanoma. The differential diagnosis is wide but an acquired brown streak in the nail of a fair-skinned adult person must be considered a potential melanoma. Dermoscopy helps clinicians to more accurately decide if a nail apparatus biopsy is necessary.

Objective: Detailed evaluation of clinical and dermoscopy features and description of conservative surgery of in situ NUM.

Methods: Retrospective study of in situ NUM diagnosed and treated with conservative surgical management in the authors' center from 2008 to 2013.

Results: Six cases of NUM were identified: 2 male and 4 female patients, age range at diagnosis of 44 to 76 years. All patients underwent complete nail unit removal with at least 6-mm security margins around the anatomic boundaries of the nail. The follow-up varies from 4 to 62 months.

Conclusion: Nail unit melanomas pose a difficult diagnostic and therapeutic challenge. Wide excision is sufficient, whereas phalanx amputation is unnecessary and associated with significant morbidity for patients with in situ or early invasive melanoma. Full-thickness skin grafting or second-intention healing after total nail unit excision is a simple procedure providing a good functional and cosmetic outcome.