The impact of biopsy technique on upstaging, residual disease, and outcome in cutaneous melanoma

BackgroundAfter skin biopsy of malignant melanoma, the findings in the subsequent wide local excision (WLE) sometimes result in upgrading of the T-category. Herein, we examine the influence of biopsy technique on residual disease in melanoma WLE specimens and on upstaging.MethodsWe performed a retrospective review of data from malignant melanoma patients who underwent sentinel lymph node biopsy between 1997 and 2010.ResultsA total of 609 patients were biopsied by shave (51%), punch (19%), and excision (30%). Residual disease was seen in 240 patients (39%) at WLE, of whom 60% had undergone shave biopsy. Fifty-nine patients had a T-category upgrade after WLE (10% of all patients); 64% were sampled by shave. Seven percent of patients with a T-category upgrade had negative margins initially. Positive biopsy margin and greater thickness predicted T-category upgrade.ConclusionsPartial biopsy for melanoma resulted in more residual disease at WLE and a higher rate of T-category upgrade. Moreover, the presence of negative margins at biopsy did not ensure lack of residual disease.