Cerebrospinal Fluid (CSF)

Cellular Pathology

Principle of Examination

Cerebrospinal Fluid (CSF) is located within the subarachnoid space. It is produced by the choroids plexuses and drains into the venous sinuses. Approximately 100mls of CSF is in continuous circulation. CSF may reflect pathology within the brain, spinal cord or membranes. CSF cytology is indicated as part of an investigation of known or suspected CNS malignancy (primary or secondary) or in cases of aseptic meningitis.

Please note:

CSF must not be submitted for cytological examination where the clinical diagnosis is of known or suspected CJD. In such cases, there should be prior discussion with a consultant cytopathologist.

In accordance with Laboratory Safety Committee guidelines, acellular or paucicellular specimens may not be processed by the Cytopathology Department. In this case, we will issue a report referring to the microbiological result only.

Specimen Requirements

CSF cytology is usually performed in conjunction with CSF microbiology and biochemistry tests. CSF cytology is indicated as part of an investigation of known or suspected central nervous system malignancy. The possibility of multiple sclerosis is not an indication for CSF cytology.

When sending cerebrospinal fluid samples for Cytology, please:

To ensure best results, we request that as much fresh specimen (10ml recommended, minimum of 2-3mls required) be sent to the laboratory as soon possible. Ideally within 2 hours of collection.
Put aliquot for cytology in a clean universal container and add an Epic request for Cytology
Include adequate clinical information provided with the request, which will clarify the indication for CSF examination
Indicate on the request if there is a history of relevant foreign travel
Send a separate sample and request for microbiological investigation if an infection is suspected
State date and time of sample collection on request

Specimen Delivery and Labelling

All Trust specimens must be requested on Epic and labelled with an Epic label.

HIGH RISK SPECIMENS: Requests must indicate if a specimen is high risk. Please indicate details of the risk, eg: TB, blood-borne virus, MPOX etc.

URGENT SPECIMENS: Please label urgent specimens clearly; an explanation as to why the specimen is urgent is helpful. On receipt, laboratory staff will notify the pathologist who will report the specimen as soon as possible.

Turnaround Time

The Laboratory aims to comply with The Royal College of Pathologists Key Performance Indicator (KPI 6.4) for Cellular Pathology reporting turnaround times with 90% of all cases reported within 10 calendar days.

Specimen Labelling Procedure