Melanocytic 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.
The 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.
Serial 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.
The 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%.
In conclusion, the nuclear immunostains (MITF and SOX10) show the most promise for improving the diagnosis of MIS in chronically sun-damaged skin.
*Mount Sinai Beth Israel Dermatologic Oncology, New York, New York;
†The Ronald O. Perelman Department of Dermatology, New York University School of Medicine, New York, New York;
‡SkinCare Physicians, Chestnut Hill, Massachusetts;
§Department of Pathology, Dermatopathology Section, New York University School of Medicine, New York, New York
Address correspondence and reprint requests to: Shane A. Meehan, MD, Department of Pathology, Dermatopathology Section, New York University School of Medicine, 240 E. 38th Street, 11th Floor, New York, NY 10016, or e-mail: firstname.lastname@example.org
The authors have indicated no significant interest with commercial supporters.
IRB approval status: reviewed by the New York University School of Medicine's Institutional Review Board, Study #s16-01701.