"Functional" surgery in subungual melanoma.

Background: Subungual melanomas represent approximately 2% to 3% of cutaneous melanomas in White populations. Complete or partial amputation proximal to the distal interphalangeal joint of the digits has been suggested. Recently, we introduced for acral melanomas, similar to lentigo maligna melanoma, limited excision and complete histology of excisional margins (three-dimensional histology).

Objective: To evaluate the prognostic relevance of clinical parameters and different surgical management in patients with subungual melanoma.

Study Design: From 1980 to 1999, subungual melanoma was diagnosed in 62 of 3,960 stage I and II melanoma patients (1.6%) of the melanoma registry of the Department of Dermatology (University of Tuebingen). A retrospective comparative analysis of two treatment groups was performed: Thirty-one patients had an amputation in or proximal to the distal interphalangeal joint (median follow-up of 55 months), and 31 patients had "functional" surgery with local excision of the tumor and only partial resection of the distal phalanx (median follow-up of 54 months).

Results: In the univariate analysis, the level of invasion (P=0.0059), ulceration (P=0.0024), and tumor thickness (P=0.0004) were significant prognostic factors for recurrence-free survival but not for survival. In a multivariate analysis, only lower tumor thickness and a reduced level of amputation were independent significant prognostic parameters for recurrence-free survival (P=0.035 and P=0.0069). Patients with an amputation in or proximal to the distal interphalangeal joint did not fare better than patients with less radical "functional" surgery.

Conclusion: Limited excision with partial resection of the distal phalanx only and three-dimensional histology to assure tumor-free resection margins give better cosmetic and functional results and do not negatively affect the prognosis of patients with subungual melanoma.