BRAF and cancer: Submitting these cells for next-generation sequencing ultimately revealed a BRAF V600E mutation typically found in PXAs, thereby confirming the diagnosis of leptomeningeal recurrence and revealing a therapeutic target.<h4>Conclusion</h4>This case highlights the utility of next-generation sequencing as a means of non-invasively diagnosing leptomeningeal disease in recurrent PXA and potentially in other cancer types as well.