Novel 16-minute technique for evaluating melanoma resection margins during Mohs surgery.

Background: Immunohistochemistry (IHC) applied to Mohs micrographic surgery (MMS) is time consuming and labor intensive, and the variability of staining quality has prevented its widespread use in clinical practice.
Objective: To investigate the readability of immunostains processed by a novel automated 16-minute technique used for evaluation of frozen sections prepared during MMS for melanoma.
Methods: A rapid automated instrument that performs MART-1 (melanoma antigen recognized by T cells) immunostains in 16 minutes was used to stain frozen sections and was compared with MART-1 stains of paraffin (permanent) sections, hematoxylin-eosin (H&E) stains of frozen and permanent sections from the positive or negative control specimens of the Mohs layers for melanoma. A total of 480 interpretations from 48 sections (4 types of stains for each specimen, 12 specimens read by 10 interpreters) were analyzed via blinded examination by 5 dermatopathologists and 5 Mohs surgeons at two institutions. A scoring system was used to assess the readability of each slide. Analysis of variance was used for statistical analysis.
Results: In terms of clarity of interpreting melanoma sections, the 16-minute MART-1 IHC of frozen sections is equivalent to the standard MART-1 of permanent sections. The 16-minute MART-1 sections are also significantly easier to interpret than permanent sections stained with H&E for both the dermatopathologists and Mohs surgeons (P < .05).
Limitations: The study represents data collected from only two institutions in the United States.
Conclusion: The rapid-stained frozen IHC sections are significantly easier to interpret than the "gold standard" permanent sections stained with H&E. This technology facilitates the rapid interpretation of melanoma in frozen sections.
(Copyright © 2010 American Academy of Dermatology, Inc. Published by Mosby, Inc. All rights reserved.)