The utility of dermoscopy-guided histologic sectioning for the diagnosis of melanocytic lesions: A case-control study Presented at the American Society of Dermatopathology Annual Meeting on October 11, 2015 in San Francisco, CA.

Background Dermoscopy allows for visualization of morphologic structures beyond the epidermis, including features that may indicate early malignant transformation. However, dermoscopic features are rarely considered during routine histologic sectioning, and areas of clinical concern may be missed during microscopic evaluation. Objective We assessed the diagnostic impact of a dermoscopy-guided micropunch score for the evaluation of melanocytic lesions. Methods In this case-control study, we evaluated 150 scored melanocytic lesions. Original tissue specimens were reprocessed to create a control group, in which a new score was introduced elsewhere in the lesion to guide an alternative plane of section. Slides were reviewed in a randomized, double-blinded manner to assess histologic features and render a diagnosis. Dermoscopy was also reviewed. Results The proportion of cases with a higher grade in the original, dermoscopy-guided section was statistically significant. Four invasive melanomas were exclusively identified using the scoring protocol. The presence of regression structures, negative pigment network, radial streaming or pseudopods, and irregular blotches were highly specific for a higher diagnostic grade. Limitations This study is retrospective and reprocessing tissue does not perfectly mimic routine sectioning. Conclusion Dermoscopy can identify important, histologically high-grade areas, and this information can be used to optimize the sectioning of melanocytic neoplasms.