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A Robust Discovery Platform for the Identification of Novel Mediators of Melanoma Metastasis
Published on: March 8, 2022
Pigmented Epithelioid Melanocytomas and Their Mimics; Focus on Their Novel Molecular Findings
Erol C Bayraktar1, George Jour1,2,3
1Department of Pathology, NYU Grossman School of Medicine, New York, NY 10016, USA.
Abstract:
Pigmented epithelioid melanocytoma (PEM) is a unique tumor with significantly pigmented appearance and indolent behavior; however, it can demonstrate cytological atypia and metastasize to local lymph nodes. Clinical and histomorphological overlap between PEM and its lower or higher-grade mimics can make it difficult to distinguish in certain cases. Genomic, transcriptomic and epigenetic data indicate that PEMs are molecularly distinct entities from other melanocytic neoplasms and melanomas. In addition, methylation studies are emerging as a tool that can be useful in difficult cases. In this review, we focus on the clinical, histopathologic and recent insights in the molecular features of pigmented epithelioid melanocytic melanocytomas and their mimics. We also present a challenging case that was resolved using methylation analysis providing a proof of concept for using epigenetic studies for similar challenging cases.
Insights
Pigmented epithelioid melanocytoma (PEM) is a distinct tumor that can mimic other melanocytic neoplasms. Methylation analysis aids in diagnosing challenging PEM cases, distinguishing them from mimics.
Area of Science:
- Dermatopathology
- Oncology
- Molecular Diagnostics
Background:
- Pigmented epithelioid melanocytoma (PEM) presents a diagnostic challenge due to overlapping features with other melanocytic neoplasms.
- While generally indolent, PEM can exhibit cytological atypia and lymph node metastasis.
- Molecular data confirms PEM as a distinct entity from melanomas and other melanocytic tumors.
Purpose of the Study:
- To review the clinical, histopathologic, and molecular features of PEM and its mimics.
- To highlight the utility of emerging epigenetic studies, specifically methylation analysis, in challenging diagnostic scenarios.
- To present a case study demonstrating the successful application of methylation analysis for PEM diagnosis.
Main Methods:
- Review of existing literature on PEM, its mimics, and molecular profiling.
- Analysis of genomic, transcriptomic, and epigenetic data differentiating PEM.
- Case presentation involving a difficult diagnosis resolved by methylation profiling.
Main Results:
- PEM is molecularly distinct from other melanocytic neoplasms.
- Methylation studies show promise as a diagnostic tool for challenging cases.
- Epigenetic analysis successfully resolved a complex diagnostic case of PEM.
Conclusions:
- PEM is a unique entity with specific molecular characteristics.
- Methylation analysis provides a valuable adjunctive method for diagnosing ambiguous melanocytic lesions.
- Epigenetic profiling offers a powerful approach for improving diagnostic accuracy in challenging dermatopathology cases.
