Does shave biopsy accurately predict the final breslow depth of primary cutaneous melanoma?

Shave biopsy (SB) is used for the diagnosis of suspicious skin lesions, including melanoma. Its accuracy for melanoma has not been confirmed. We examined our experience with SB to determine its ability to predict true Breslow depth (BD). We performed a retrospective review of the tumor registry for all patients diagnosed with melanoma by SB from 1995 to 2004. Site and depth of lesion, tumor stage, correlation of BD between SB and wide local excision (WLE), and changes in surgical management due to discordance were examined. Melanoma-in-situ was defined as a depth of 0 for this analysis. One hundred thirty-nine patients were diagnosed with melanoma by SB. Pathology after WLE were as follows: 54 (39%) patients had no residual disease, 67 (48%) had a BD equal to or less than the SB, and 18 (13%) had a thicker BD compared with the SB. For these 18 patients, the median BD by SB and WLE was 1.1 mm (range 0-6.5) and 3.5 mm (range 0.5-20.5), respectively (P = 0.0017). Upstaging of final BD from SB to WLE was significantly associated with increasing tumor depth and higher stage of melanoma (P < 0.0001). Only seven of the 139 patients (5%) required further surgery because of the increased depth of the WLE. SB underestimated the final BD of melanoma in 13 per cent of patients, but changed the management of few patients. SB is a valuable tool for practitioners in the diagnosis of melanoma. Nevertheless, patients diagnosed with melanoma by SB should be counseled about the rare need for additional surgery.