Polypoid Spitz Nevus With a Halo Reaction.

Area of Science:

• Dermatopathology
• Oncology
• Genetics

Background:

• Spitz nevi are melanocytic tumors with varying presentations.
• Polypoid morphology and halo reactions are individually uncommon in Spitz nevi.
• The co-occurrence of polypoid morphology and halo reaction is exceptionally rare.

Observation:

• A 10-year-old male presented with a polypoid Spitz nevus exhibiting a halo reaction on his back.
• The lesion was evaluated for specific molecular markers and genetic alterations.
• Clinical follow-up was conducted to monitor for recurrence.

Findings:

• The Spitz nevus demonstrated preserved nuclear expression of BAP1.
• Immunohistochemistry revealed no expression of BRAF and ALK, but p16 expression was noted in melanocytic cells.
• Comparative genomic hybridization identified only minor losses on chromosome 8, with no significant aberrations.

Implications:

• This case expands the known spectrum of Spitz nevus presentations.
• The findings contribute to understanding the molecular profile of rare Spitz nevus variants.
• The absence of significant genetic aberrations and recurrence suggests a benign clinical course for this specific presentation.