Melanoma cell plasticity poses diagnostic challenges: a case series

Area of Science:

• Oncology
• Cancer Biology
• Pathology

Background:

• Phenotype switching, or cancer cell plasticity, is an emerging area in melanoma research.
• Metastatic melanoma can exhibit significant changes in morphology and immunohistochemistry over time.
• These changes can lead to diagnostic challenges, mimicking other malignancies.

Purpose of the Study:

• To present cases of metastatic malignant melanoma exhibiting phenotype switching.
• To emphasize the diagnostic difficulties arising from these phenotypic changes.
• To highlight the role of advanced molecular techniques in confirming melanoma diagnosis.

Main Methods:

• Case study analysis of five patients with metastatic malignant melanoma.
• Morphological and immunohistochemical evaluation of tumor samples.
• Next-generation sequencing (NGS) for mutational profiling to compare with primary lesions or lymph nodes.

Main Results:

• Five cases demonstrated metastatic melanoma with dramatic changes, resembling other cancers.
• Diagnosis was confirmed by comparing NGS mutational profiles of metastatic sites to primary tumors or lymph nodes.
• Pathological assessment showed diagnostic discrepancies due to phenotypic alterations.

Conclusions:

• Phenotype switching in metastatic melanoma can cause significant diagnostic challenges.
• Next-generation sequencing is a vital tool for accurate melanoma diagnosis when morphology is misleading.
• Thorough diagnostic evaluation is essential for patients with progressive metastatic melanoma and pathological discrepancies.