Reproducibility of histopathologic diagnosis of skin diseases by digital photomicrographs versus conventional optical microscopy.

Background: Telepathology is considered a good alternative for a second opinion consultation. Its implementation is desirable, but studies to confirm its practical application are required.
Objectives: To evaluate the reproducibility of histopathologic diagnoses of skin diseases obtained through digital photomicrographs compared with conventional microscopy.
Methods: We evaluated the surgical specimens of 135 patients using an optical microscope. After 4 weeks, the same consultants independently evaluated a total of 1,738 digital photomicrographs obtained from the histopathological slides. We estimated the overall rate of intra and interobserver agreement, and the Kappa coefficient was obtained with the categorization of the skin diseases: neoplastic skin diseases, infectious-contagious skin diseases and non-infectious-contagious skin diseases.
Results: Consultant 1 obtained an agreement of 88.1% (95% CI = 81.5% - 93.1%) between conventional microscopy and images. Consultant 2 obtained an agreement of 80.7% (95% CI = 73.1% - 87%). The interobserver agreement for the microscopy analysis was 81.5% (95% CI = 73.9% - 87.6%). The same analysis using microphotography showed an agreement of 85.9% (95% CI = 78.9% - 91.3%). The Kappa coefficient, which evaluated the categorized skin diseases, was 98.6% for Consultant 1, 93.1% for Consultant 2, 95.8% for interconsultant analyses of images and 95.9% for interconsultant analyses using conventional optical microscopy. All of these values are considered optimal.
Conclusion: The evaluation of microphotographs shows a good level of reproducibility when compared to traditional microscopy and, therefore, is a viable option for a second opinion consultation in dermatopathology.