Evaluation of MITF, SOX10, MART-1, and R21 Immunostaining for the Diagnosis of Residual Melanoma In Situ on Chronically Sun-Damaged Skin

• Published in: Dermatologic surgery Vol. 44; no. 7; pp. 933 - 938
• Main Authors: Mu, Euphemia W, Quatrano, Nicola A, Yagerman, Sarah E, Ratner, Desiree, Meehan, Shane A
• Format: Journal Article
• Language: English
• Published: United States by the American Society for Dermatologic Surgery, Inc. Published by Wolters Kluwer Health, Inc. All rights reserved 01-07-2018
• Subjects: Antibodies, Monoclonal - metabolism; Humans; MART-1 Antigen - metabolism; Melanocytes; Melanoma - diagnosis; Melanoma - metabolism; Microphthalmia-Associated Transcription Factor - metabolism; Neoplasm, Residual; Observer Variation; Sensitivity and Specificity; Skin Aging; Skin Neoplasms - diagnosis; Skin Neoplasms - metabolism; SOXE Transcription Factors - metabolism
• ISSN: 1076-0512; 1524-4725
• DOI: 10.1097/DSS.0000000000001493

BACKGROUNDMelanocytic immunostains can assist in margin evaluation of melanoma in situ (MIS) excisions; however, their accuracy and reliability relative to hematoxylin & eosin (H&E) is yet to be determined.
OBJECTIVEThe objective of this study was to evaluate the sensitivity, specificity, and concordance of 4 melanocyte-specific immunostains for diagnosing MIS occurring on chronically sun-damaged skin.
MATERIALS AND METHODSSerial permanent sections from representative areas of negative margin and residual tumor were stained using H&E, MITF, MART-1, SOX10, and R21 and examined in a blinded fashion. The study set included 100 digital microscopy images from 10 cases of MIS excisions from the face. Two board-certified dermatopathologists, 4 fellowship-trained Mohs surgeons, 2 Mohs fellows, and 2 dermatology residents independently reviewed the 100 images.
RESULTSThe average melanocyte density was 11 versus 28 melanocytes per 0.5 mm for chronically sun-damaged skin versus residual MIS on H&E, respectively. Statistically significantly higher melanocyte densities were observed using MITF, MART-1, and SOX10 on negative margins. The sensitivity and interobserver concordance was highest using MITF and SOX10. The intraobserver agreement on 4 duplicate images was 85%.
CONCLUSIONIn conclusion, the nuclear immunostains (MITF and SOX10) show the most promise for improving the diagnosis of MIS in chronically sun-damaged skin.