Dysplastic (or Atypical) Nevi Showing Moderate or Severe Atypia With Clear Margins on the Shave Removal Specimens Are Most Likely Completely Excised

Abstract

Background: Dysplastic nevi (DN) are graded by their degree of atypia into 3 categories of mild, moderate, and severe. In many practices, DN with moderate or severe atypia are generally excised regardless of the status of the shave specimen margins. Objective: With a new approach toward the margins on the shave removal specimens (SRS), the goal herein is to assess whether the shave removal procedure can sufficiently remove DN with moderate or severe atypia. Methods: A total of 426 SRS diagnosed with DN showing moderate or severe atypia between January and December 2015 along with their post–shave excision specimens were reviewed. Based on the author’s experience, clear or negative margins on the SRS were defined as neoplastic melanocytes confined within >0.2 mm of the lateral and deep specimen margins. The biopsy specimens were accompanied by Melan-A highlighting the subtle neoplastic cells. Results: With a negative predictive value (NPV) of 98.4% (confidence interval: 97.2% to 100%, P < .001), DN showing moderate or severe atypia with clear margins are most likely removed by the shave procedure. Conclusion: Routine excision of DN showing moderate or severe atypia with clear margins on SRS is not necessary. Regular surveillance is sufficient.