TUMOR CELL DETECTION BY IMMUNOFLOW CYTOMETRY AND BRAF MUTATION ANALYSIS IN CEREBROSPINAL FLUID OF MELANOMA PATIENTS WITH SUSPECTED LEPTOMENINGEAL METASTASES

INTRODUCTION Approximately five percent of melanoma patients develop leptomeningeal metastases (LM). Diagnosis of LM can be made on clinical symptoms and typical contrast enhancement of the leptomeninges on MRI brain or spine and/or CSF cytology. However, MRI has a sensitivity of 76% and a specificity of 77%. Sensitivity of CSF cytology is also low: 55% at first analysis, increasing to 80% upon second sampling.