Spitz melanocytic tumours - a review

Area of Science:

• Dermatopathology
• Oncology
• Molecular Pathology

Background:

• Spitz tumours represent a spectrum of melanocytic proliferations with shared cytological and molecular features.
• Distinguishing benign Spitz tumours with atypical features from melanomas poses significant diagnostic challenges.
• Recent advances in understanding molecular pathways offer potential for more objective diagnoses.

Purpose of the Study:

• To elucidate the role of molecular pathways in differentiating Spitz tumours.
• To establish objective criteria for classifying Spitz naevi, Spitz melanocytoma, and Spitz melanoma.
• To reduce diagnostic uncertainty in the evaluation of Spitz neoplasms.

Main Methods:

• Analysis of cytological and histopathological features of Spitz tumours.
• Investigation of genomic aberrations and molecular pathways, including HRAS aberrations and kinase fusions.
• Correlation of molecular findings with histopathological classifications.

Main Results:

• The presence of specific Spitz molecular pathways (e.g., HRAS aberrations, kinase fusions) distinguishes true Spitz neoplasms.
• Spitz naevi show benign histopathological and molecular findings.
• Spitz melanoma exhibits malignant histopathological features or ambiguous findings with melanoma-associated genetic aberrations.
• Spitz melanocytoma is characterized by intermediate histopathological and genetic/genomic profiles.

Conclusions:

• Molecular pathway analysis provides objective criteria for classifying Spitz tumours.
• Distinguishing between Spitz naevi, Spitz melanocytoma, and Spitz melanoma is improved through integrated histopathological and molecular evaluation.
• This approach aims to reduce diagnostic uncertainty and improve patient management.