Optical super-high magnification dermoscopy of benign and malignant melanocytic lesions in correlation with histopathology.

Background and objectives: Technical advances have allowed for significant improvements in imaging techniques in recent years. Specifically, lesions can now be depicted at a much higher magnification - up to 400 x - using optical super-high magnification dermoscopy (OSHMD).

Patients and methods: This is a retrospective, observational study assessing 99 melanocytic lesions in patients from the University Hospital Heidelberg. Dermoscopy (20 x) and OSHMD images (90 x, 120 x, 150 x, 180 x and 270 x) were acquired. OSHMD images were assessed for the presence/absence of pigment network, distribution, size and color of cells, dots and roundish nests (small/large), structureless areas and vessels in nevi versus melanomas. Correlation studies with histopathology were performed.

Results: We found that in OSHMD atypical pigment network, irregular dark dots, atypical vessels and irregular grey out-of-focus cells are clues to melanoma. Black dots and small roundish nests in OSHMD images corresponded to nests of atypical melanocytes in melanomas in histopathology. Grey out-of-focus cells in OSHMD images corresponded to melanophages in histopathology and in irregular distribution were found more frequently in melanomas.

Conclusions: We conclude that knowing about histopathological correlates OSHMD may support differentiating nevi from melanomas.