The impact of shave biopsy on the management of patients with thin melanomas.

Disagreement persists regarding the role that various biopsy methods should play in the diagnosis of primary cutaneous melanoma. We analyzed the indications for sentinel lymph node (SLN) biopsy and the rates of SLN involvement among biopsy techniques and deep margin status to attempt to determine impact of shave biopsy on surgical management of patients with thin melanoma. All patients who underwent SLN biopsy for melanoma with Breslow thickness less than 1 mm between 1998 and 2006 were identified. Patient and tumor characteristics were compared using χ(2) tests for categorical variables. Continuous variables were reported as a mean ± standard deviation and analyzed using t test. Of the 260 patients diagnosed with thin melanomas, 159 (61.2%) were diagnosed by shave biopsy; 101 (38.8%) were diagnosed by other techniques. Of the 159 patients diagnosed by shave biopsy, 18.2 per cent (n = 29) underwent SLN biopsy with the only indication being positive deep margin. The frequency of SLN positivity did not differ between the biopsy groups (3.1% vs 4.0%, P = 0.726) or between groups that had positive or negative deep margins (3.0% vs 3.3%, P = 0.839, respectively). For patients unable to undergo general anesthesia, the increased rate of performing SLN biopsy resulting from shave biopsy should limit its use in these patients. However, shave biopsy is a reasonable diagnostic method for patients at low risk for general anesthesia, particularly because it results in comparably low rates of positive SLN. Thus each patient's unique clinical situation should be considered when deciding which biopsy technique is appropriate.