Application of 3-dimensional reflectance confocal microscopy: Melanocytic proliferations as three-dimensional models

To the Editor: Melanoma on chronically sun-damaged skin (MSDS) is challenging to detect.1Sanchez M.I. Rabinovitz H.S. Oliverio M.C. Elgart G.W. Grichnik J.M. Confocal microscopy of dermoscopic diagnoses.Arch Dermatol. 2012; 148: 1224Crossref PubMed Scopus (1) Google Scholar Reflectance confocal (RCM) increases diagnostic accuracy but relies upon interpretation 2-dimensional (2D) horizontal sections. Our objective was determine whether existing technology could be used create 3-dimensional (3D) models, which would expand data available for discriminating biology. Melanocytic cells have different morphologic appearances dependent developmental stage, activation status, and pathogenic genetic epigenetic alterations. Cell shape, therefore, can provide clues a cell's behavior. We reconstructed individual melanoma from stacks RCM images (Fig 1; Supplemental Fig 1, via Mendeley at https://data.mendeley.com/datasets/7kx38d9h2v/3). Distinct morphologies identified, including spindle, spheroid, heavily dendritic cell forms. These 3D reconstructions also allowed modeling nuclear shapes insets). Because image sizes are known, it possible calculate cellular volumes, may increase accuracy.2Chang C.K. Tsai C.C. Hsu W.Y. et al.Segmentation nucleus cytoplasm single in three-dimensional tomogram using optical coherence tomography [published correction appears J Biomed Opt. 2017;22(3):39801].J 2017; 22: 36003Crossref (11) Monomorphism or pleomorphism melanocytes diagnosis. In some tumors, relatively uniform, presenting as sheets spindle-shaped cells, monomorphic spheroidal-shaped heavy mats dendrites. However, other tumors display more variation with epithelioid, spindle-shaped, all appearing 500-?m field (Supplemental 2). Location important The presence melanocytic middle upper epidermis (pagetoid spread) suggest malignancy, whereas superficial dermis invasion. Within context volume, we renderings show (epidermal) lower (dermal) regions simultaneously 3). This not only identification pagetoid invasive locations examining extent melanization that imply differences maturation. When visualizing normal pigmented benign neoplasms RCM, bright rims (edging) around dermal papillae visible rings when viewed plane, primarily due melanin-containing basal keratinocytes. By rendering stack vertical axis, arrangement refractile along apparent 2, 4). Epidermal thickness calculated, well length epidermal ridge volume 3D. MSDS present, asymmetric pigmentation (partially edged nonedged papillae) noted papillae.3Serrano P.F.-C. Segurado-Miravalles G. González S. oncological dermatology.in: Nouri K. Lasers Dermatology Medicine. Springer, 2018: 375-400Google phenomenon nonuniform melanin transfer population density differences. dermoepidermal junction frequently becomes flattened malignant tumors. phenomena best evaluated process currently has limitations. manual segmentation techniques used, complex models take hours produce, limiting bedside use. imaging area limited dimensions (500 ?m × 500 ?m). anisotropic, thus noncubic voxels require interpolation resampling render accurately space.4Trusk T.C. reconstruction data.in: Gray W. Price J.R.L. Basic Microscopy. Cham2018: 279-307Crossref summary, supplementary information, beyond what appreciable 2D images, melanocyte morphology, pleomorphism, location. allows detailed evaluation contour, reflect summation keratinocytic, melanocytic, immunologic, microenvironmental events.