PRE-ANALYTICAL
PROCEDURE FOR INFORMATION FOR PRE-EXAMINATION ACTIVITIES, COLLECTION AND TRANSPORTATION OF SAMPLES
Surgical biopsy specimens are received as soon as possible in histopathology laboratory in 10% buffered formalin in appropriate amount along with properly filled requisition form. Frozen section specimen/ tissue is received in normal saline. The specimens are transported in a properly sealed puncture proof container with universal safety precautions.
QUALITY CONTROL:
pH of 10% buffered formalin is maintained between 6.8 to 7.2 which is freshly prepared every day. 10% buffered formalin is provided to nursing staff. Records which are maintained.
PROCEDURE FOR SAMPLE RECEVEING
Labelled surgical biopsy/specimens are received containing patient's name, age, sex, MRD no., department, unit, location, date and time of sample collection, type of sample collection, probable diagnosis and complete clinical history. After checking all these details, unique H.P. no. is given to specimen and entered in receiving register.
QUALITY CONTROL:
No specimen is rejected. In case of any discrepancy of identification, missing details or poor preservation of the tissue, clinician is informed and necessary corrective actions are taken, record of which is maintained and documented. Receiving register is maintained.
PROCEDURE FOR HANDLING AND PREPARATION OF
SPECIMENS
Specimens are received in formalin container and on receiving the specimen formalin is changed. Small biopsies are whole passed. The large specimens are cut at interval of 1 cm and cotton soaked in formalin is placed in between and are kept for 24 hours for fixation. Next day, grossing is done as per CAP guidelines.
TISSUE PROCESSING
After grossing, tissue cassettes are arranged in the bucket for automated tissue processing or for manual processing in a manner that reagents penetrate in all cassettes equally. The duration for automated tissue processor for one cycle is 16 hours during which tissue passes through different reagents like formalin, increasing concentration of alcohol, xylene and paraffin wax. After this, tissue embedding is done and blocks are prepared.
TISSUE EMBEDDING AND BLOCK PREPARATION
After tissue processing is over the tissues are embedded in to melted paraffin, The thermal unit/ hot plate is used for melting the wax maintaining the temperature at
60-65 degree Celsius and cooling unit is used for block preparation with maintenance of temperature at -4 degree Celsius.
MICROTOMY
Blocks are put on ice plate prior to cutting for 15 minutes and then blocks are trimmed and then are kept in block holder. First small biopsies are cut and then larger tissues are cut with setting blade at angle of 45 degree, further ribbons or strips are shifted to water bath with maintenance of temperature at 65 degree Celsius. Then slides are labelled by diamond pencil as per label on the block.
QUALITY CONTROL PROCEDURE:
H& E STAINING AND MOUNTINGPREPARATION, STAINING PROCEDURE
For H & E staining sections are dipped in xylene giving two changes in 15 minutes to dewax the sections. After that, sections are put in the two different concentration of alcohol for 4 minutes and sections are kept to air dry. Then sections are dipped in water two times after which sections are stained by Harris Hematoxylin for 5 minutes. Wash sections in tap water for 5 minutes. After that, dip the sections in 1% acid alcohol and wash with sodium bicarbonate. Sections are checked for hematoxylin staining and then last step of staining the sections with 1% eosin is carried out. Final wash with water is done and after it mounting is done.
ANALYTICAL
REPORTING
Routinely hierarchal form of reporting is followed. CAP/AJCC guidelines are followed for reporting. Recent WHO guidelines are also taken into consideration. Prior to dispatch of reports, reports are reviewed by authorized faculty by evaluating them with an appropriate available clinical information, macroscopic findings and microscopic findings. Typographical errors are taken care and corrected.
QUALITY CONTROL FOR REPORTING:
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INTERLAB QUALITY ASSESMENT (Neu-QAP, BANGALORE) We receive 4 cycles of virtual histopathology cases and 4 conventional cycles of tissue for processing and slide diagnosis (HPE examination of EQA) in a year (pre-analytical & analytical). The results and details of EQA and interlaboratory are stored in HP:C/records/2/results of EQAS and interlaboratory comparison.
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INTERNAL QUALITY CONTROL: Intradepartmental consultation (review of randomly selected cases) is done by another authorized faculty for routine histopathological and frozen section.
Monthly one case of histopathology is randomly selected for examination by another authorized faculty of other section of the department. Findings of both are recorded and records are monitored annually. More than 90% concordant diagnosis/findings are considered as satisfactory.
We take into consideration the Turn around time of our laboratory for 4 working days for small biopsies and all specimen, less than 30 min for frozen cytology and less than 30 min for frozen histopathology specimens. >80% limits are considered good and >90% are considered excellent score. For continuous improvement, faculties attend CMEs and conferences.
POST-ANALYTICAL
Signed reports are dispatched to person appointed for the same by hospital authorities and records of same are maintained in dispatch register. Incidental malignancy/ change in type of malignancy or positive surgical margin is considered as critical alert and the requester is notified immediately about critical results whenever found, records of which are maintained. We maintain turnaround time for small biopsies and all specimen – 4 working days and for intraoperative frozen specimen 30 minutes. The results of TAT are analyzed monthly, corrective actions taken and documented.
| Histopathology IQC Plan | ||||
|---|---|---|---|---|
| No. of product groups | No. of tests/ calibration parameters | Does the IQC plan broadly cover all tests/calibrations & details thereof | Frequency of IQC checks | Compliance criteria |
| 1.Biopsy (small, medium & large tissues; Slides and blocks for second opinion): | * Grossing * Decalcification * Processing * Paraffin embedding - Microtomy - H&E staining * Light Microscopy with interpretation | -Lot validation with every change of reagent Lot - Section cutting and staining of each person Every 15 days - Daily QC for H&E staining - Inter observer quality control once in a month | ||
| 2.Histochemistry: | * PAS( Periodic Acid Schiff) stain * Reticulin (Gordon and Sweet’s) stain * Perl’s Prussian blue stain for Iron * ZN (Ziehl Neelsen) stain for AFB * Masson Trichrome stain * Grocott Methanamine Silver Stain * Alcian Blue stain * Toludine Blue - Giemsa (May Grunwald Giemsa) | - IQC with each special stain -Lot validation with every change of reagent lot | ||
| 3.Tissue received in normal saline: | * Grossing * Processing & section cutting by cryostat H & E staining | Slides of each case for frozen section is sent for review by another authorised signatory posted in other section |
IQC Procedure
Monthly one case each of histopathology and frozen section is randomly selected for examination by another authorized faculty of other section of the department. Findings of both are recorded and records are monitored annually. More than 90% concordant diagnosis/findings are considered as satisfactory.
Staining quality for histopathology slides is validated daily and records are maintained. Microtomy quality for thickness of histopathology section is validated 2 times in a month and records are maintained. Appropriate remarks are documented and records are monitored monthly.
Lot validation of every reagent is done and records of which is maintained. Records are monitored annually. All Records are retained for a period of one year.
EQUAS Plan
| > EQAS/ PT providers (or) ILC/ coordinating CAB | > PT programme No. | Parameter | |
|---|---|---|---|
| Neu-QAP171 EQA program from Neuberg Anand Academy of Laboratory Medicine,Banglore (Pre analytical & analytical cycle 4cycles annually) -Virtual cycle: 4 cycles annually | > ILQA –HP 70 | Pre-analytical: technical parameter Analytical: reporting parameters Reporting parameter |
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EQUAS Procedure
Four cycles of histopathology EQA is received within a year. Cases of histopathology EQAS includes a tissue for processing and analysis and virtual slides images. Feedback report for each participant is evaluated with each cycle. A final report of tissue processing analysis is given as a preanalytic scoring. Out of 5 score, 3 score is require attention by the laboratory. To consider satisfactory performance of virtual slides the diagnosis should fall into concordant diagnosis by majority of the participants. Documents are retained for one year or till next assessment, whichever is later.
NCHSLS Surat
As there is no provision for allocation of financial resources for examination charges and sample transport facility required for Inter Laboratory/Inter Instrument Comparison, there exist no inter laboratory/inter instrument comparison for Histopathology and Cytopathology.
Laboratory Director,
NCHSLS,
Surat.