Cellular Pathology

Histopathology specimens

Please avoid batching specimens. Please send specimens to the department as soon as possible. Do not leave to the end of a long operating list or in the theatre/clinic over the weekend.

Surgical specimens

Please note that formaldehyde is known to be carcinogenic in high doses and suitable precautions must be taken when dealing with it.

Specimens should be placed in 10% buffered formal saline in a properly sealed container, with an adhesive label indicating the toxic nature of formalin. Sometimes, especially with larger specimens, this may not be possible and these should be sent to the laboratory as soon as possible for gross dissection, or dissected by the surgeon at the time of operation. However, every effort must be made to place specimens in suitably sized containers and there should be enough fixative to cause total immersion of the specimen by at least 10 times its own volume. The specimens should not be refrigerated.

Failure to use adequate amounts of buffered formal saline will result in potential loss of morphology, the potential loss of diagnostic information within the specimen and will also hinder ability to perform subsequent tests that may be required for diagnosis. 

In cases where gout is suspected specimens are best placed in alcohol and not aqueous solutions. Please telephone the laboratory for advice.

Specimen pots and Fixative supplies

The department supplies containers and some fixatives to users as required. The following sizes of specimen container are available:

· 60ml pre-filled (10% formalin)

· 120ml pre-filled (10% formalin)

· bucket sizes 500ml pots ; 1L buckets; 2.5L buckets; 5L buckets ; 10L buckets

Specimens for immunofluorescence (hospital only)

Immunofluorescence is used mainly on cutaneous biopsies. Specimens should be sent immediately to the histopathology laboratory, to arrive within 30 minutes of excision in normal working hours. If this is not possible transport medium must be used (Michel’s) and the specimen kept refrigerated. This is available from the laboratory. Formalin must not be used as it will render the specimen uninterpretable.

The protocol for sending muscle biopsies can be obtained after direct discussion with the department (ext 6093 at Epsom Hospital and ext 2495 St Helier Hospital). 

Renal biopsies

Renal biopsies should be placed in 10% buffered formal saline and not sent fresh.

Urgent Renal Biopsies for same day processing should be sent to the St. Helier laboratory by 1:00pm for the results to be available by 5:00pm.

Testicular biopsies for investigation of subfertility/infertility

These should be placed in Bouin’s solution (available from the laboratory if not present in theatres).

Lymph nodes

Lymph nodes removed from suspected lymphoma should be sent as soon as possible to the laboratory to facilitate prompt transport to the Royal Marsden where these are processed.

If it is not possible to do this immediately or if lymph nodes are sent outside normal working hours, place in buffered formal saline and send to the laboratory. 

If lymphoma is not the primary clinical suspicion, lymph nodes should be placed in buffered formal saline and will be processed in the department.

If microbiological examination is required, the lymph node must be divided, and a portion placed in a sterile container and submitted to microbiology directly without fixative.

Gastrointestinal specimens  

All specimens should be transported to the laboratory in buffered formal saline. Segments of bowel that contain tumours that involve less than the full circumference should be opened through the uninvolved part.  

Muscle biopsies 

Muscle biopsies, after prior consultation with the laboratory and King’s College Hospital (tel. 020 3299 1957 the day before the procedure), may be processed at King's College Hospital – Department of Clinical Neuropathology.

Diagnostic material from paediatric neoplasms should be sent directly to the Pathology Department at St George's Hospital.

The protocol for sending muscle biopsies can be obtained after direct discussion with the department (ext 2495 St Helier Hospital and ext 6093 at Epsom Hospital).

Transportation

Specimens should be sent in dedicated pots or containers with the lids tightly closed. These should be placed in a leak-proof plastic bag, preferably one having separate compartments, one for the specimen and one for the accompanying request card.

Completion of histopathology requests

When completing the request form the sender is declaring that the patient has consented to this investigation.

Request forms should include three patient identifiers, details of sending clinician and location for report to be sent, clinician information and date the specimen was taken. The specimen pot should also have three patient identifiers as a minimum including the NHS number (to help prevent the duplication of medical computer records which is a potential clinical risk).

Specimens lacking correct information or where there is a discrepancy in this data will be returned to sender for inclusion of these details. Incorrect requests lacking sufficient clinical information will significantly delay the issue of the histopathology report.

Specimens should be sent to the laboratory as quickly as possible to prevent both deterioration and to assure rapid diagnosis. If there is a delay in the ability to send fresh material, this should be kept in the fridge until transportation is possible. Specimens in formal saline should not be refrigerated.

Multiple specimens

If multiple specimens are removed, each is to be placed in a separate container and labelled with the usual demographic data and either a number or other distinguishing feature, eg site. If a numbering system is used then the sites to which the numbers relate must be shown on the request form.

Non-gynaecological cytology specimens

Specimens received without the information detailed above will be rejected. The department will make contact with the requesting clinician in an attempt to complete any missing information where possible. Thorough and relevant clinical information is vital.

Non-gynae samples such as pleural fluids, ascitic fluids, peritoneal fluids, pericardial fluids, synovial (joint) fluids, CSFs, fine needle aspirates, cyst fluids and urines should be in 30 ml white topped universal containers.

Bronchial washings, bronchoalveolar lavages and sputum samples should be in 30 ml universal containers or bronchoscopy traps.

Larger volumes should be decanted into universal containers.

Urine samples should be in 30 ml universal containers

Urines sent for microbiology and culture have boric acid but urines sent for cytological analysis DO NOT have boric acid.

Formalin should not be used as a cytology fixative – any samples in formaldehyde will be rejected.

It is essential that non-cervical cytology samples are sent to the laboratory as soon as possible to ensure good preservation and to prevent bacterial overgrowth. If transport is delayed, specimens must be stored in a refrigerator. To ensure safe transportation, each sample is sealed in an individual specimen bag and kept separate from the request form (front pouch of bag).

Turnaround times

The turnaround time target for Histopathology specimens is as follows:

• 90% of cases available within ten working days.

Turnaround time commitments are calculated from the date received not the date sent. These are normally:

• Five working days for specimens labelled urgent by clinicians or pathologists (urgency can also be added later at the pathologist's discretion).
• Seven working days for Two Week Rule specimens.
• Ten working days for 'non-urgent samples' and 'major resections'.
• Calcified material such as bone may take longer than this and thedecalcification time is not predictable.

If clinicians phone for a case which is still within the turnaround time period they will be informed that the result will be on Clinical Manager by the expected turnaround time limit.

Only cases that have exceeded the turnaround time or where there is a change of clinical need will be brought to the attention of the pathologist. If a clinician is bringing a patient back or requires a result in less than ten days, this has to be mentioned in the request form at the time of ordering the test.

The turnaround time for non-gynaecological specimens is as follows:

• 80% of cases within 7 working days, 90% of all cases within 10 working days.

There are some factors that may affect the histological interpretation of results.

· Crushing small biopsies with forceps before placing them in fixative.

· Allowing the tissue to dry out once it has been removed.

· Prolonged storage at room temperature or above before fixation.

· The type and concentration of fixative.

· An inadequate volume of fixative.

· Fresh tissue delayed before arriving at the laboratory.

· A lack of previous history, clinical information or patient details.

Urgent specimens

These should be discussed with laboratory staff (ext 6093 at Epsom Hospital and ext 2495 at St Helier Hospital) in the first instance and the request form marked ‘urgent’ appropriately.

If there are special requirements with regards to speed of a result including Two Week Rule Cases, these should be clearly stated on the request form, eg result required by….

Only a small number of cases can be handled in this way so please limit such requests to cases of genuine urgent clinical need. 

Frozen sections

Contact the laboratory at least 24 hours before the operation to book the frozen section and confirm that a pathologist is available at the planned time (ext. 6093 for Epsom ext. 2495 for St Helier).

Except in exceptional circumstances frozen sections can only be done between 9am and 5pm. There is no funded out of hours or on call service. If frozen sections are required on patients with AIDS or other infectious conditions please contact one of the consultant histopathologists. 

Details required: 

• Date and time
• Surgeon
• Patient’s name
• Nature of specimen and clinical context
• Telephone/bleep number for report

Send the specimen in a dry container without fixative by hand as quickly as possible with the request form directly to the Histology laboratory. Do not take specimens to pathology reception.

The report for single block cases will be telephoned to the number given within 30 minutes of receipt of the specimen. Complex cases, such as those with multiple blocks to establish clearance, will take longer. 

Risk of infection

High risk specimens must be clearly identified on request form and specimen container.

Surgical resections, biopsies and specimens known or suspected to be high risk of infection (HBV, HIV, TB and CJD) require additional handling precautions.

Specimens such as complete lymph nodes and larger tissue resections are seldom completely fixed when they reach the laboratory. Such specimens from 'high risk' patients should be left in fixative in a container until adequately fixed before processing. This may mean several days immersion and a judgment will be made in each case.

Frozen sections of unfixed material from high risk patients will not be prepared. In exceptional circumstances it may be possible to prepare frozen sections of unfixed material from such patients but only after prior arrangement with the histopathology laboratory and full discussion with a consultant histopathologist. 

Storage

Surgical specimens are stored for approximately six weeks after a report is issued. If new clinical information becomes apparent that might require further investigation of the unprocessed tissue, if available, these should be raised during this period. Diagnostic slides are kept for a minimum of ten years and tissue blocks for a minimum of thirty years.

Any specimen or report may be discussed with the consultant histopathologist. 

Telephone enquiries, results over the telephone and the report

Reports are imported into clinical manager or sent via electronic links to outside users where these have been established. A hard copy is also sent to the sender/responsible clinician stated on the request card.

Reports on lymphoreticular pathology, where primarily reported by the Royal Marsden Hospital are dispatched by the Royal Marsden Hospital via e-mail to the histology department. Reports are transcribed on to Telepath and the original reports are printed and kept on file in the histology department.

Please do not request results by telephone, except in emergencies. Only validated results of histopathological/cytopathological diagnosis are to be communicated to the requesting clinician or an authorised deputy, by a histopathology consultant or secretary (with specific authorisation for each case) and only if the identity of the enquirer is beyond doubt.

Cellular Pathology reports

The department provides interpretative reports detailing a description of the specimen received and the histological opinion of the reporting Pathologist. Any measurements, counts and weights are approximations or estimates only and need to be interpreted as such within the clinical context. They do not have specific tolerance or guaranteed absolute accuracy. This applies to both histopathological and cytological specimens. 

Unaccredited tests

The department is currently ISO 15189 accredited and the majority of the tests provided are accredited. Synovial fluid crystal examination and Phospholipase A2 staining are not part of this accreditation.

Cervical Screening

Cervical Screening is provided by Health Services Laboratories (HSL) for London including Sutton and Merton patients.

The Doctors Laboratory Ltd
The Halo Building
1 Mabledon Place
London
WC1H 9AX

General Enquiries
Tel: 020 7307 7373

https://tdlpathology.com/services-divisions/tdl-cytology/

Cervical screening is provided by the Berkshire and Surrey Pathology Services.

Gynaecological Cytopathology
St Peter’s Hospital
Guildford Road
Lyne, Chertsey
KT16 0PZ

Tel: 01932 723542

https://www.berkshireandsurreypathologyservices.nhs.uk/screening-programmes/nhs-cervical-screening-programme-hpv-primary-screening-service/