Histopathology

Contact numbers

Histopathology contact numbers are included in the Cellular Pathology contacts.

Opening hours

Monday to Friday: 0830 to 1700h

Availability of clinical advice and interpretation

Consultant pathologists are available via the secretaries' office between the hours of 8.30am to 5pm, Monday to Friday. No on-call service is provided.

Request forms

It is the responsibility of the requesting doctor or source to complete the request form fully. All relevant details and history must be entered in the space provided.

Request forms are available for wards and departments from stationery using an ad hoc requisition form. GPs may request forms from the histology office on ext. 64110.

Specimen containers

Pre-labelled, pre-filled (neutral buffered formalin) containers are available from the pathology store on (66)4407.  

Five litre containers of neutral buffered formalin are available from histopathology on ext. 64591.

Specimen labelling

All specimens must be labelled with full patient identification and be accompanied by a request form giving full clinical details and signed by a doctor, in accordance with UHSPE Pathology Sample and Request Form Labelling Requirements.

Due to medico-legal considerations, all unlabelled or mislabelled specimens will require identification and verification prior to processing. The same applies to specimens arriving with no form, a mislabelled form or insufficient data.

Specimen packaging

1. Packaging must be of good quality, strong enough to withstand the shocks and loadings normally encountered during transport. Individual primary receptacles and the secondary packages should be tightly closed and sealed with tape or other means to prevent leakage (“Ziplock”® bags would meet this requirement).

2. The packaging shall consist of at least three components. The outer packaging must be rigid.

1. 1. a primary receptacle
   2. a secondary packaging, and
   3. an outer packaging

of which either the secondary or the outer packaging shall be rigid.

Road vehicles which collect from surgeries, clinics etc. are often fitted with box(es) into which the collected item is placed. Such boxes may be considered to constitute the outer packaging. Collected items must consist of a primary receptacle and a secondary packaging.

3. Primary receptacles shall be packed in secondary packaging in such a way that, under normal conditions of transport, they cannot break, be punctured or leak their contents into the secondary packaging. Secondary packaging shall be secured in outer packaging with suitable cushioning material.

Specimen transport & delivery

Specimens are to be delivered to pathology reception. All histopathology specimens should be received in formalin unless for frozen section, when the case should be discussed with the laboratory before leaving theatres.

Specimen transportation

Sample packs arrive at the laboratories via several routes from service users.

Internally they are delivered by clinical staff/ward staff/porters/healthcare assistants in person. It is expected that sample packs will be delivered promptly to maintain their integrity for testing. If users are delivering samples in batches they must ensure all samples within the batch are able to withstand any batching delay.

Externally, sample packs will also be delivered by the courier service from external sources such as GP surgeries and clinics in batches also. Again the sample packs must remain viable throughout the batching time. If viability could be impacted external users are required to liaise with the laboratory or the designated courier themselves to have bespoke collections.

Certain specimens must be delivered to the laboratory as soon as possible:

• CSF samples (these should not be taken after 3pm, to allow for transport and preparation time).
• Fresh tissue specimens including those for frozen sectioning.

Treatment of specimens

Routine specimens

Adequately fixed tissue is vital in the interpretation of histopathology. For most specimens the tissue should be placed immediately into fixative (10% Formalin). The container must be of a suitable size: at least 3X the maximum dimension of the specimen. The specimen MUST be completely immersed in 10% Formalin (optimum is 10X the volume of the specimen) and sent to the laboratory as soon as possible. The exception to this is tissue requiring a frozen section (see specimens requiring special treatment).

What happens to a specimen?

Histological specimens are usually placed into a fixative solution of 10% buffered formalin immediately after excision. Specimens are fixed for a minimum of 12 hours before being examined by a pathologist. The pathologist records the macroscopic appearance and for large specimens selects the pieces to be processed. Small biopsies are processed completely. The tissue is then processed overnight. The next day wax blocks are prepared and slides cut and stained for the pathologist to report.

Key factors known to affect performance

In order for the laboratory to perform the correct tests and provide the appropriate results it is important for requesting clinicians to be aware of the factors which can affect test performance and the interpretation of results, for example:

• Sample placed in 10% formalin when a fresh specimen is required e.g. for frozen section or Hirschsprung disease,
• Sample place in wrong container e.g. cytology container containing preservative instead of 10% formalin,
• Delay in transportation with fresh samples,
• Insufficient supply of clinical details, e.g. synovial fluid which does not state "for crystal analysis".

If in any doubt, please contact the laboratory for advice.

Turnaround time

Currently we are not reaching our targeted turn around time of 90% of all specimens within 10 days but are achieving approximately half of our cases in 10 days. We are working through a number of improvements and hope to achieve our target in the near future.

Diagnoses are usually made on sections stained by routine techniques but not infrequently cases require more sophisticated and extensive studies. Specimens requiring special techniques or decalcification will take longer.

Cases deemed to be clinically urgent should be discussed with a consultant prior to the specimen being sent to the laboratory.

Cases requiring additional routine in-house reflex biomarker analysis have an additional turnaround time of 7 days from the time of request.

All genomic/molecular tests sent to the South East Genomic Laboratory Hub (SEGLH) at Guy’s Cancer Genetics are specified by NHSE. Urgent cancer referrals are 14 days. Non-urgent cancer referrals are 21 days.

Additional tests

All specimens are kept for approximately 2 months, blocks are kept for a minimum of 30 years should additional testing be required. Any additional tests must be arranged through direct contact with the reporting consultant.

Urgent biopsies

The average time for a routine specimen may be shortened if there are urgent clinical decisions to be made. The degree of urgency should be indicated on the request form. If the result is to be phoned, a bleep, or telephone number must be given on the request form. Any cases requiring a result within 24 hours should be discussed with a Consultant Pathologist, who will explain the possible options for processing of the specimen.

Diagnostic testing referral centres

The choice of referral for a second clinical opinion is the decision of the reporting consultant although many will be guided by regional agreement.

All molecular and genomic testing is now performed at the SEGLH:

All PD-L1s (excluding PD-L1 for NSCLC) are referred to:

Somatic BRCA & HRD testing for ovarian tumours are referred to:

Designated referral centres

Certain specimen types are routinely referred to designated external consultants for a second clinical opinion. These are:

Specimens requiring special treatment

Frozen sections

24 hours' notice is required if tissue is to be sent for frozen section. This is to ensure that equipment and staff are available. The specimen must be brought directly to the laboratory and must be unfixed. Please telephone the laboratory (ext. 64591) to inform them that the specimen is on its way.

It is the responsibility of the requesting source to organise the transport directly to the laboratory if the specimen is not on site.

The request form must state what the frozen section is for and must give a contact name telephone number to ring with the result. Frozen sections will not be performed on high-risk specimens unless there is an adequate clinical reason. Please contact a consultant histopathologist to discuss.

Joint fluids for crystals

Listed under cytopathology tests.

Testing for Hirschsprung Disease

Where possible the laboratory should be given 24hrs notice by contacting ext. 64625 or 64591. Please state if a result is needed urgently whilst the patient remains in the operating theatre.

In order for the maximum amount of tests to be performed, two specimens should ideally be sent to the laboratory.

• One fresh specimen which has been adhered to the side of the specimen container. A wad of saline soaked gauze should be placed at the bottom of the container before inserting the specimen.
• One specimen fixed in 10% buffered formalin.

The request form must state that testing for Hirschsprung Disease is required; a contact telephone number must also be given.

Specimens must be hand delivered to Pathology reception ASAP as fresh specimens deteriorate rapidly with time, which could adversely affect the test results.

The turnaround time for these specimens is approximately 10 days however a verbal result from the fresh specimen can be given the same or next day (depending on when the specimen is received into the department).

Special investigations

Some biopsies will require further investigation before a report can be issued. Examples include lymphomas or unusual tumours that require special stains or immunocytochemistry. The reports on these cases will take longer because the special stains take several days. In urgent cases the consultant pathologist may be able to give a provisional verbal report.

Please note: ICOS & CXCL13 used as a part of Immunohistochemistry panel testing are not accredited by UKAS.

Electron Microscopy

Electron microscopy is routinely carried out on all native renal biopsies and renal transplant biopsies when required for diagnosis.

All renal biopsies are treated as urgent by the laboratory. If a same day result is required, specimens must be received into the laboratory by 12 noon at the latest.

When sending a renal biopsy please use a pre-filled 10% formal saline specimen pot which are located in the renal treatment room cupboard at RSCH. If supplies of these are running low please contact ext. 64616 or ext. 64591 to request more pots.

Reports

Reports are generated via the secretariat and are dispatched to the sender source. If further copies are required please indicate on the request form.

It should, however, be noted that departmental policy is that scientific and clerical staff cannot give results over the telephone, but will provide reprints for collection or post. When this is insufficient for clinical needs, consultant pathologists will give verbal results to medical staff. Urgent cases and verbal results can be given to an authorised source, at the discretion of a consultant histopathologist.