Ex vivo dermoscopy of melanocytic tumors: time for dermatopathologists to learn dermoscopy.

BACKGROUND: We have identified cases of skin cancer with discordances between clinical, dermoscopic, and histopathologic findings that were likely due to sampling errors in the pathology laboratory. This has prompted us to explore the use of ex vivo dermoscopy as an ancillary method of gross pathology, which may serve to guide tissue sectioning. Noncontact polarized dermoscopy was applied to pigmented lesions before excision and at least 6 hours after specimen fixation in formalin.

OBSERVATIONS: The orientation of the lesion, overall dermoscopic pattern, and dermoscopic pigmented structures (network, globules, and peripheral streaks) were readily correlated between the in vivo and ex vivo images for 2 melanomas and 4 dysplastic nevi. Blood vessels were not observed in the ex vivo dermoscopic images, which limited their correlation with the in vivo dermoscopic images for basal cell carcinoma.

CONCLUSIONS: Dermoscopy can be applied to fixed tissues, with findings comparable to those of in vivo examination. This observation may serve as the first step toward using dermoscopy to guide tissue sectioning in gross pathology.