GNAQ mutation in primary spinal melanoma: illustrative case

Area of Science:

• Neuro-oncology
• Dermatopathology
• Genetics

Background:

• Primary spinal melanoma is an exceptionally rare tumor lacking identifiable primary dermal or uveal lesions.
• Its rarity presents significant diagnostic and therapeutic challenges.

Purpose of the Study:

• To report a case of primary spinal melanoma.
• To elucidate the potential molecular mechanisms driving its tumorigenesis.

Main Methods:

• Case presentation of a 74-year-old male with spinal symptoms.
• Diagnostic workup including MRI, histopathology, and immunohistochemistry.
• Next-generation sequencing to identify genetic mutations.

Main Results:

• MRI revealed an intradural, extramedullary lesion at T11-12.
• Histopathology confirmed primary spinal melanoma.
• Next-generation sequencing identified a guanine-nucleotide binding protein (GNAQ) mutation.

Conclusions:

• GNAQ mutations may initiate primary spinal melanoma by activating beta-catenin in neural crest cells.
• Aberrant proliferation of ectopic melanocytes is linked to downstream RAS/RAF pathway activation.
• Understanding this pathomechanism could lead to targeted therapies for primary central nervous system melanoma.