Management of in situ melanoma of the nail apparatus with functional surgery: report of 11 cases and review of the literature

Abstract

Nail apparatus melanoma (NAM) is a rare melanocytic neoplasm with pejorative prognosis often related to late diagnosis. Early diagnosis at in situ stage (NAMis) is difficult, but essential to improve prognosis. NAMis management is not well established yet. Removal of the whole nail unit has been advocated in several small series as a potential treatment for NAMis. To report and assess 'functional' or 'conservative' surgery for NAMis and evaluate its long-term oncologic safety. Retrospective study of cases diagnosed in the University Hospital Saint-Pierre collected over a 13 year period and compared with the published data. Eleven cases of NAMis were identified: 73% concerned females. Thumb and first toe were the most affected digits (63% of total). Monodactylic longitudinal melanonychia (LM) was the most frequent presentation (92%). Mean diagnosis delay was 5 years. Diagnosis was suspected on the basis of clinical and dermatoscopic signs and was confirmed by pathological examination. All patients underwent complete nail unit removal with 6 mm security margins around the anatomic boundaries of the nail. Two late local recurrences were observed at 7 and 11 years follow-up. Our series, the largest up to now, demonstrates that 'functional surgery' is a rational approach for NAMis with an excellent oncologic safety at 5 years. However, this study suggests that a very long-term follow-up is mandatory, as recurrences may appear late.