Diagnostic Cytology

The Cytology Unit is a section within the Histopathology Department. The unit processes some 25,500 cervical smear screening tests and 3,300 diagnostic samples which include fluid specimens, brush specimens and Fine Needle Aspiration (FNA) Cytology. The Unit also operates an FNA Clinic for palpable lesions. This service is currently only available to hospital clinicians.

The cytology laboratory working hours are 9am to 5:30 pm, Monday to Thursday and 9am to 5pm on Friday (excluding bank holidays). A limited out of hours service is provided by the Histology Department at the weekend to deal with urgent CSF and PCP bronchial lavage specimens.
Sample type and Volume required: 
All diagnostic cytology specimens should be accompanied by a completed request form which must include the patient’s name and address, date of birth/NHS Number/Hospital Number, ward or clinic if seen in hospital, and sender’s name and contact details. The type of specimen and the sample site, if appropriate, should be clearly stated on the form and clinical details provided.

*Fluid Specimens*

These include urine, serous fluids, sputum, cyst aspirates, washings and CSF’s. A sample of 20ml maximum size is adequate for cytology in almost all cases. Larger volumes should not be sent to the laboratory without prior approval from the laboratory. It is appreciated that some samples, such as CSF’s, are often of low volume and smaller samples are acceptable in such circumstances.

Fluid specimens should be sent to the laboratory without delay in a suitable specimen container. The container should be labelled with the patient’s first and last name and NHS number or hospital number or date of birth. The label should also include the type of specimen and site of sample, if appropriate. The specimen and the request form should be sent to the laboratory in a plastic specimen bag.

*Brushings and FNA Specimens*

FNA specimens and brushings should be spread on frosted end slides. The slides should be labelled in pencil (ink is washed off in processing) to include the patients name and date of birth. If samples are taken from multiple sites, it will be necessary to number the slides to indicate the sources. The slides may be air dried for low viscosity specimens or wet fixed if the material is mucoid. Ideally, if sufficient material is available, slides prepared by both methods should be sent. Slides must be placed in slide transport boxes and placed in a specimen bag with the request form for delivery to the laboratory.

Excess material can be expressed into physiological saline or tissue culture fluid and sent to the laboratory as for fluid specimens.
Turnaround time: 
Diagnostic Cytology specimens are normally reported within 4/5 days. On occasion, more specialised techniques may be employed to improve diagnostic value. This may incur a slight delay of between 24 and 48 hours. _Where the result is required on the same day, please inform the cytology laboratory by phone. It is essential that such specimens are received in the laboratory before 4pm._
Cellular Pathology at Guy's And St Thomas' Hospital
Histology: 0207 188 7188 extension 54611 , Cytology: 0207 188 2915, Oral Pathology: 0207 188 4367
Histopathology & Cytopathology Laboratories
Cellular Pathology
St Thomas' Hospital
North Wing - 2nd Floor
Westminster Bridge Road
London SE1 7EH

Head and Neck/Oral Pathology Laboratory
4th Floor, Tower Wing
Guy's Hospital
Great Maze Pond
London SE1 9RT

For clinical advice or interpretation of results, please contact the laboratory in the first instance.

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Last updated: 07/08/2015