A spinal needle is inserted, usually between the third and fourth lumbar vertebrae in the lower spine.
Once the needle is properly positioned in the subarachnoid space (the space between the spinal cord and its covering, the meninges), pressures can be measured and fluid can be collected for testing..
CSF analysis usually consists of opening pressure measurement, biochemical analysis, cytology, biomarkers assay, and microbiological evaluation.
In some clinical conditions, lumbar puncture and drainage of can be a therapeutic measure also..
Specimen Requirements:
Collect a minimum of 3 mL of CSF.
If flow cytometry for lymphoma/leukemia is required, provide as much specimen as possible (CSF for flow cytometry must be submitted fresh).
Collect and transport specimens according to Biological Substance, Category B, and shipping guidelines..
The primary role of CSF cytology is to exclude circulating malignant cells in CSF pathways.
Although a specific diagnosis of some benign diseases (e.g., cryptococcosis) can be made cytologically, in most nonmalignant central nervous system (CNS) diseases CSF cytology is frustratingly unrevealing..
