Enhanced Melan‐A Red Chromogen Labeling in Melanoma Compared to Nevus Cells: A Diagnostic Aid in Dual Multiplex Immunohistochemistry With Ki67
- 1Department of Anatomical Pathology The University of Texas MD Anderson Cancer Center Houston Texas USA
Abstract
Background: Distinguishing melanoma cells from nevus cells remains a diagnostic challenge, particularly in cases where melanoma exhibits nevoid morphology or nevus cells display atypical or epithelioid features. Accurate identification is essential for proper measurement of Breslow depth in melanomas arising in association with nevi and for margin assessment, both of which are critical for patient prognosis. The dual multiplex immunohistochemical stain utilizing Melan‐A (red chromogen) and Ki67 (brown chromogen) is a valuable tool for assessing the proliferative index of melanocytic populations, with melanoma cells typically showing a higher Ki67 index than nevus cells.
Methods: We identified 10 cases with invasive melanoma and associated nevus present on the same scanned histologic section for which the signing pathologist had ordered this dual multiplex immunohistochemical study. We annotated areas of melanoma versus nevus, then quantified the staining intensities.
Results: Melanoma cells often demonstrate more intense Melan‐A red chromogen labeling than adjacent nevus cells (p = 0.008; Wilcoxon signed rank test).
Conclusion: This differential labeling provides a helpful visual distinction between melanoma and nevus cells within the same histologic section, enhancing diagnostic confidence beyond the difference in Ki67 proliferation index.
Related
- Multiplex immunohistochemistry in multiple myeloma: principles, spatial profiling applications, and emerging frontiers in immuno-oncology
- Complex sclerosing lesions of the breast mimicking carcinoma: diagnostic pitfalls and the decisive role of immunohistochemistry
- Diagnostic Accuracy of VE1 Immunohistochemistry for BRAF p.V600E in Colorectal Carcinoma: A Systematic Review
- Diagnostic Utility of PRAME Immunohistochemistry for Distinguishing Acral Melanoma From Acral Melanocytic Nevi
- Enhancing diagnostic accuracy with core needle biopsy and immunohistochemistry in indeterminate thyroid nodules: a retrospective diagnostic accuracy study.
BibTeX
@article{kundert2026enhanced,
title = {{Enhanced Melan‐A Red Chromogen Labeling in Melanoma Compared to Nevus Cells: A Diagnostic Aid in Dual Multiplex Immunohistochemistry With Ki67}},
author = {Peter N. Kundert and Elsayed H. Ibrahim and Victor G. Prieto and Phyu P. Aung},
journal = {Journal of Cutaneous Pathology},
year = {2026},
month = jul,
doi = {10.1111/cup.70170},
url = {https://doi.org/10.1111/cup.70170},
note = {CC BY-NC-ND 4.0},
}
RIS
TY - JOUR
TI - Enhanced Melan‐A Red Chromogen Labeling in Melanoma Compared to Nevus Cells: A Diagnostic Aid in Dual Multiplex Immunohistochemistry With Ki67
AU - Peter N. Kundert
AU - Elsayed H. Ibrahim
AU - Victor G. Prieto
AU - Phyu P. Aung
PY - 2026
DA - 2026/07/30
JO - Journal of Cutaneous Pathology
DO - 10.1111/cup.70170
UR - https://doi.org/10.1111/cup.70170
AB - Background: Distinguishing melanoma cells from nevus cells remains a diagnostic challenge, particularly in cases where melanoma exhibits nevoid morphology or nevus cells display atypical or epithelioid features. Accurate identification is essential for proper measurement of Breslow depth in melanomas arising in association with nevi and for margin assessment, both of which are critical for patient prognosis. The dual multiplex immunohistochemical stain utilizing Melan‐A (red chromogen) and Ki67 (brown chromogen) is a valuable tool for assessing the proliferative index of melanocytic populations, with melanoma cells typically showing a higher Ki67 index than nevus cells. Methods: We identified 10 cases with invasive melanoma and associated nevus present on the same scanned histologic section for which the signing pathologist had ordered this dual multiplex immunohistochemical study. We annotated areas of melanoma versus nevus, then quantified the staining intensities. Results: Melanoma cells often demonstrate more intense Melan‐A red chromogen labeling than adjacent nevus cells (p = 0.008; Wilcoxon signed rank test). Conclusion: This differential labeling provides a helpful visual distinction between melanoma and nevus cells within the same histologic section, enhancing diagnostic confidence beyond the difference in Ki67 proliferation index.
SN - 0303-6987
SN - 1600-0560
ER -