Deep margin involvement after shave biopsy for melanoma and requirement for sentinel lymph node biopsy (SLNB).

Abstract

e19029 Background: One indication for SLNB in thin melanomas is an involved deep margin. While shave biopsy is discouraged as a method of diagnosing pigmented lesions, it is frequently used by dermatologists, particularly in the community. This approach can lead to a positive deep margin, which would result in unnecessary SLNBs. Patients undergoing SLNB for melanoma were analyzed to determine how frequently shave biopsy with positive margins alone led to a recommendation for SLNB. Methods: Patients who underwent SLNB for primary cutaneous melanoma with Breslow thickness less than 1 mm between 2000 and 2006 were identified from the Emory Prospective Melanoma Database. Charts were reviewed for patient, diagnostic and therapeutic data to determine how frequently a shave biopsy with a positive deep margin was the only indication for SLNB. Results: Of 250 melanomas with Breslow thickness less than 1 mm that underwent SLNB, 156 (62%) were shave biopsies of which 85 (34%) were transected with positive deep margins. Sixty-one (72%) of these were Clark's Level IV and 1 (1.1%) was ulcerated. Thus 27% (n = 23) of patients with positive deep margins from shave biopsy underwent SLNB with no other indication. Of the 85 transected shave biopsies, 3 (3.5%) had a positive SLNB compared with 2 (2.8%) of the remaining 71 nontransected shave biopsies. Conclusions: For patients at high risk for general anesthesia the increased rate of SLNBs due to shave biopsy warrants careful consideration of the use of this biopsy technique. However, shave biopsy may be a reasonable diagnostic method for patients at low risk for general anesthesia. Shave biopsy does not appear to impact incidence of positive SLNBs. No significant financial relationships to disclose.