DNA methylation array analysis for diffuse leptomeningeal glioneuronal tumor with conspicuous hypothalamic mass. A...

Area of Science:

• Neuro-oncology
• Molecular diagnostics
• Pediatric neurosurgery

Background:

• Diffuse leptomeningeal glioneuronal tumor (DLGNT) is a rare CNS neoplasm with diagnostic challenges due to varied histopathological and radiological features.
• Accurate diagnosis and subtyping of DLGNT are crucial for appropriate treatment strategies.
• Molecular testing, particularly DNA methylation array, is emerging as a tool to improve diagnostic accuracy in ambiguous brain tumors.

Observation:

• A 14-year-old girl presented with a hypothalamic mass and diffuse leptomeningeal enhancement on MRI.
• Endoscopic biopsy revealed oligodendrocyte-like cells, but histological findings were non-specific, hindering definitive diagnosis.
• DNA methylation array analysis was performed on formalin-fixed, paraffin-embedded tissue.

Findings:

• DNA methylation array analysis diagnosed the case as the indolent MC-1 subtype of DLGNT with a high calibrated score (0.99).
• This molecular subtyping facilitated conservative treatment management.
• The patient showed no tumor progression or symptom aggravation over 12 months of follow-up.

Implications:

• DNA methylation array analysis is a powerful tool for accurate diagnosis and subtyping of DLGNT.
• Molecular subtyping aids in treatment decision-making for rare glioneuronal tumors.
• This approach can potentially improve patient outcomes by guiding therapy selection.