The role of comparative digital nuclear analysis of malignant and benign acral melanocytic lesions

• Grant number: 24/07040-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: November 01, 2024
• End date: October 31, 2025
• Field of knowledge: Health Sciences - Medicine - Pathological Anatomy and Clinical Pathology
• Principal Investigator: José Cândido Caldeira Xavier Júnior
• Grantee: Angel Gabriel Boscolo Ruivo
• Host Institution: Centro Universitário Católico Salesiano Auxilium Araçatuba (UNISALESIANO). Missão Salesiana de Ensino de Mato Grosso. Araçatuba , SP, Brazil

Abstract

Introduction: Cutaneous melanoma is the eighth most common malignant neoplasm worldwide and the deadliest among skin cancers. There are several subtypes of melanoma, resulting from a wide range of gene mutations and their impacts on cell proliferation pathways. Image-based methodologies play a crucial role in medicine showing tremendous growth in recent decades. The use of digital analysis software allows reproducible extraction of information from images with possible diagnostic value. ImageJ is an open-source program used for visualizing, inspecting, quantifying, and validating scientific image data.Immunohistochemistry is a well-established, widely used in the histopathological examination of neoplasms. For melanocytic lesions the following markers are noteworthy: PRAME (preferentially expressed antigen in melanomas, associated with more aggressive tumor phenotypes when overexpressed) and Melan-A.The combination of immunohistochemistry and digital image analysis with ImageJ software allows for a detailed quantitative and qualitative assessment of lesions and presents itself as a promising alternative. The differential diagnosis between junctional acral nevi and in situ acral melanomas is challenging due to the morphological similarity of these lesions. Traditional methods, such as clinical examination and dermoscopy, have limitations, particularly in early detection. Thus, the use of digital analysis tools, such as the ImageJ software, and immunohistochemical biomarkers emerges as a promising approach to improve diagnostic accuracy.The relevance of the project is justified by the fact that, to date, there is no published Brazilian article which has conducted this type of melanocyte analysis focus on acral melanocytic lesions. Therefore, this integration between immunohistochemistry and digital analysis would promote a more robust and accurate approach, increasing reliability in the differential diagnosis of acral melanocytic lesions and enabling the development of new, easily reproducible diagnostic tools.Objectives: To compare the morphology of melanocytes in benign and malignant acral lesions using the ImageJ software, with the assistance of immunohistochemical studies (using PRAME and Melan-A); To determine whether cytological findings identified through ImageJ software - assisted by immunohistochemical studies with the markers PRAME and Melan-A - (such as area, perimeter, circularity, density, height, width, etc.) can serve as auxiliary tools in the diagnosis and prognosis of acral melanocytic lesions.Methods: A retrospective observational study will be based on digital evaluation - assisted by immunohistochemical studies using the markers PRAME and Melan-A - of scanned histological images from patients whose diagnoses were made at the Instituto de Patologia de Araçatuba up to the year 2018. The twenty most recent cases of each entity (acral nevus of junctional nature and acral melanoma in situ) for which slides are available in the laboratory archive will be selected. The slides will be reviewed, and the diagnoses of benign and malignant melanocytic lesions will be confirmed by consensus between two pathologists, then they will be scanned using the Aperio CSTM equipment (Leica Biosystems, USA) at 40X magnification. Using the ImageJ software, the nuclei of junctional melanocytes will be manually selected one by one, generating data on the occupied area, shape, positioning, mean, minimum, and maximum points, and distribution.Expected Results: The expected outcomes include the publication of scientific articles with author credits; the training of the involved student in conducting scientific research; the presentation of data at regional, national, and international conferences; and the creation of pathology protocols that could support the application of digital image analysis, assisted by immunohistochemical study, in the diagnostic routine for acral melanocytic lesions.