QUALITY CONTROL IN HISTOPATHOLOGY-MICROTOMY ,STAINING ,REPORTING.pptx

Quality control

1. QUALITY CONTROL IN HISTOPATHOLOGY-MICROTOMY ,STAINING ,REPORTING PRESENTER:DR.SHITAL HARNE MODERATOR:DR ANJALI KULKARNI

2. QUALITY CONTROL Defined as a system for verifying and maintaining level of quality in an individual test or process. To be done from specimen collection until the time physician receives the report.

3. QUALITY ASSURANCE AND QUALITY IMPROVEMENT As defined by College of American Pathologists systematic monitoring of quality control results and quality control practice parameters to assure that all systems are functioning in a manner appropriate to deliver excellence in health care . Quality improvement is practice of continuously assessing and adjusting performances using statistically and scientifically accepted procedures.

4. Objectives of QC in histopathology laboratory

5. PHASES IN QUALITY CONTROL PRE-ANALYTICAL PHASE : ANALYTICAL PHASE : POST-ANALYTICAL PHASE : TURN –AROUND TIME

6. ANALYTICAL REQUIREMENTS GROSSING: The grossing room should be well ventilated with an air extractor. Brief description of sample should be written that will help in microscopic reporting.

7. Tissue processing Process of tissue processing should be fully automated . Right choice of reagents for processing schedule should be adopted. Periodic change of processing fluid is to be done according to workload of the laboratory.

8. MICROTOMY Process by which tissue is sectioned and attached to the surface of glass slide for further microscopic examination. Automated microtomes should ideally be used Improved sectioning Increased productivity and improved occupational safety .

9. Knifes used should fit specific type of microtome and to cope up with different degrees of hardness of tissues and embedding media. Most knives are use are disposable type except for tool edge knives for resin and steel knives for cryostat.

10. Clearance angle is to be adjusted in small increments to eliminate problems which occur with ribboning of the tissue . Low profile blade : High profile blade : Over-tightening of disposable blade in the clamping device may cause cutting artifacts

11. Addition of alcohol or small drop of detergent may be added to the water to reduce surface tension allowing the section to flatten out with ease. Avoid getting water bubble trapped under the section. Use distilled water in the water bath.

12. QUALITY CONTROL IN STAINING: Automated staining machine allow accurate and consistant staining, differentiation and dehydration by adjusting the times of each step. Variabilty in staining solutions used may necessitate adjustment of staining times.

13. Variations is produced in batch number ,change of supplier and pH difference . Lab produced hematoxylin may have different staining properties each time prepared despite same preparation instructions being employed . New batches are to be checked for efficacy against present and previous batches .

14. QC for routine H&E Staining Each step in staining protocol is accurately timed. These sections were cut from the same block at the same thickness and manually stained H&E by different staff members using what was supposed to be the same method. Even macroscopically, the inconsistency of the stain can be seen.

15. Control slides are regularly stained to monitor stain quality . This section of kidney includes a variety of eosinophilic tissue elements and well-preserved nuclei that allows a reliable assessment of the quality of H&E staining. Placenta is another specimen type that can be used as a useful control .

16. Ensure complete dewaxing to avoid incomplete ,uneven staining . This H&E stained section shows a large unstained area on the left and several smaller areas that are either partially stained or unstained. This is due to incomplete wax removal prior to staining.

17. Solvents and staining reagent are to be regularly replaced based upon number of slides retained or racks processed. This section shows poor quality, muddy hematoxylin staining. This reagent should be replaced immediately.

18. Slides are to thourougly hydrated prior to hematoxylin staining . The uneven hematoxylin staining visible in the epidermis in this skin section was caused by residual xylene (and traces of wax) present when the hematoxylin was applied.

19. Monitoring of hematoxylin quality as it may get diluted due to carry over from slides and rack. Two slides from the same control block are shown. They were stained H&E using identical protocols on an automated stainer but with an interval of seven days between runs. Even macroscopically, the variation in the level of staining is obvious.

20. Ensure complete nuclear bluing by using Scott’s alkaline water /ammonia water . Bluing is to be followed by thorough wash in the tap water to remove residual eosin . Monitor eosin pH

21. Thorough dehydration before clearing and putting coverslip. Avoid drying and crystal formation :Tiny air bble may get trapped over some nuclei making them appear black

22. Other factors that affect staining are fixation ,section thickening and excessive hot plate temperature. Problem in nuclear staining when other acidic dyes are used,like Von Gieson ;uniform muddy purple to sections. Minimised by using Celestine blue -alum hematoxylin sequence or iron hematoxylin like Weigert’s .

23. ACTIVITY SCORE Thickness of sections 4 Knife artifact 4 Section artifact 3.5 Absence of floaters and position of sections 5 MICROTOMY :

24. STAINING : ACTIVITY SCORE Contrast at lowest power 4 Chromatin detail 4 Hematoxylin intensity and differentiation 4 Uniformity of staining 4 Eosin intensity and selectivity 4 Residual Wax 4

25. MOUNTING AND LABBELLING : ACTIVITY SCORE Dehydration of section and clarity 4 Absence of a ir bubbles under coverslip 5 Messy mounting 4 Tissue sectioning exposed 5 Label details 5

26. Quality control in reporting Turn around time CAP protocol for reporting Intra departmental review Amended report : Corrected report : Addendum report : External quality of Assessement /Proficiency test Quality requirement review request Clinicopathological conferances

27. Quality assurance in histopathology archiving . Standard storage and archiving . Quality requirement for retained specimens and for disposable.

28. ACCREDATION Official approval given by any organization when a laboratory achieves certain defined standard. A recognized third authority body gives formal recognition /certificate for competency, authority or credibility of a laboratory .

29. A ccountability Potential increase in variety of specimens received due to enhanced patient and clinicians’ confidence. Better control of all SOPs .

30. REQUIREMENTS FOR ACHIEVING THE NABL STANDARD Space assigned for laboratory Equipments Trained Staff SOPs Quality control Laboratory Safety

31. Regular quality checks Daily observation of room temperature ,temperature of equipment ,cleaning schedule of equipment . Use of digital application . p H of buffered formalin is to be checked . Defect log of any instrument breakdown .

32. The quality of preanalytical procedures to be done weekly . Calibration of equipment at regular intervals as recommended by manufacturer . Servicing and maintenance of of equipment . Staffs need to be well trained especially when there is any change type of work and newly appointed staff to be oriented .

33. Conducting seminars and CME for continuous update/improvement in daily laboratory procedures. Non conformatories are documentary evidence of non fulfillment of specific requirement of laboratory system. NCs are documented in the format adopted by the department ,addressed, analysed for the root cause and necessary corrective and preventive actions are taken . Staff is briefed about each of the non conformity.

34. Review of documents : QC manual SOPs Equipment manual Audit manual Staff detail manual Primary sample collection manual Proficiency testing record Waste disposal record Calibration certificate

35. AUDIT : Planned and conducted to check proper functioning of system. Internal audit and external audit Horizontal audit : Verticle audit : Internal audit done at least once in a year . External audit :Third party audit conducted by accredation board.

36. TAKE HOME MESSAGE : Quality control is an integral part of a medical laboratory . It helps maintaining , assuaring and improving qualities of tests and reporting done in that laboratory . All this will help in better patient care and optimal functioning of healthcare system.

37. REFERANCES Bancroft textbook Tata Manual of histotechnologs Rosai J. Rosai and Ackerman’s Surgical pathology

38. THANK YOU !