Mohs Surgery for Squamous Cell Carcinoma of the Nail Unit: 10 Years of Experience.

Background: Squamous cell carcinoma (SCC) is the most frequent malignant tumor of the nail unit.

Objective: The aim of this study was to review the long-term outcome of patients affected by SCC of the nail who underwent Mohs surgery.

Materials And Methods: Patients affected by nail SCC were enrolled, including cases where x-ray examination had revealed bone changes. The tumor was completely excised and the defect filled with a skin substitute based on hyaluronic acid where bone involvement was not observed. Where Mohs sections indicated bone involvement, the distal phalanx was disarticulated and the remaining end of the digit repaired using a volar/plantar flap. Follow-up was performed every 6 months for 5 years.

Results: Mohs technique was performed in 43 cases. Microinvasive SCC was diagnosed in 5 cases, in situ SCC in 7 cases, and invasive SCC in 45 patients. Recurrences were observed in 2 patients (3.5%). Disarticulation was performed in both of them, and no further tumor recurrences were observed in 4 to 5 years of follow-up.

Conclusion: Mohs surgery provides the highest cure rate for the treatment of nail SCC. It allows the evaluation of periosteal invasion and therefore bone invasion to be reliably distinguished from inflammation or compression. This technique reduces the number of unnecessary amputations, a critical consideration for patient's quality of life.