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Cell block

  1. D R . V I K R A M P R A B H A K A R D C P, D N B CELL BLOCK
  2. • The traditional cell block (CB) technique was introduced more than a century ago in 1896 using a celloidin embedding medium. • However, it gained wide acceptance as a diagnostic tool in 1947.
  3. Cytology H I S T O P A T H O L O G Y
  4. SPECIMENS FOR CELL BLOCK • Body cavity effusion fluids, • FNAs, • washings, • cyst contents, • scraped material from aspirate slides or • Millipore filters and LBC specimens can all be used for the preparation of CBs.
  5. Sample Fixation Centrifugation 3000 rpm for 10 min Paraffin embedding Cutting and staining Cellular adjuvant to harden the cell palate
  6. METHODS 1) Simple sedimentation technique (Drawback of insufficient cellularity) 2) Normal saline needle rinse method :-- a) The commonly used b) Rinse the aspiration needle with 20–30 ml of normal saline, centrifuge immediately or preserve in RPMI (Rosewell Park Medical Institute) medium for future centrifugation, and collect the material for processing as for a tissue biopsy.
  7. 3) TISSUE COAGULUM CLOT (TCC) METHOD • To augment cellularity in CB sections, • The TCC method is used, without diluting the material by saline, allowing the clot of tissue and blood mixture to form in the lumen of the needle. • As the coagulum streams out from the needle tip, it is collected onto a piece of filter paper and air dried.
  8. • The clot is only slightly air dried in order to preserve cellular morphology • The tissue coagulum is then transferred into a formalin container and subsequently processed
  9. • TCC is considered to be superior to a conventional aspiration needle rinse in the recovery of cellular material and • prevention of the loss of diagnostic material.
  10. 4) PLASMA THROMBIN OR THROMBIN CLOT METHOD • A CB can be prepared from the pellet of any centrifuged cell suspension by adding plasma and thrombin to enmesh the cellular material in a clot • Although the unpredictability of clot formation and clot size in the plasma thrombin technique may cause an uneven concentration of cells, one can overcome this problem by the use of continuous agitation during clot formation to disperse the cell population evenly throughout the fibrin mesh.
  11. • Some commercially available thromboplastin reagents prepared from rabbit lung or brain contain epithelial cells, which may lead to erroneous interpretation of the case. Thus, cell-free thromboplastin should be chosen for this method.
  12. 5) USE OF ADJUVANTS • The difficulties in the recovery and processing of small tissue fragments have resulted in alternative manual CB methods which include the use of cell adjuvants, such as A) Agar B) HistoGelTM, C) Gelatin albumin D) Collodion E) Pre-gelatinized starch F) Sodium alginate G) Gelatin foam, H) Polyvinyl alcohol foam I) Acetone-melted paraffin technique J) Gelatin capsules.
  13. • Principally, the concentrated sediments are supported by a substance such as agar or a collodion bag . • Agar solidifies below 50 °C, and this property of agar is utilized to form the cell pellet. • If the cellularity is scanty, it is advisable to perform the collodion bag method. Collodion is a nitrocellulose material, which is used to make blocks of friable tissue, such as brain, in histology laboratories.
  14. USING AGAR
  15. COLLODION
  16. 6) SHANDONTM CYTOBLOCKTM METHOD • Second alternative manual CB preparation product. • By design, it concentrates cells by cytocentrifugation in a Thermo Shandon Cytospin using Cytoblock cassettes and reagents available in the kit.
  17. 7) RAPID CB METHOD • A new rapid CB technique has been used to improve the accuracy of breast FNA even in sparse material. • It increases overall cellularity with decreased time and fewer reagents. • A proprietary tissue cassette and filter assembly is designed to capture small tissue fragments and position them in a plane for microtomy. • The rapid CB technique deposits the needle rinse material in one plane, resulting in a higher yield of tissue fragments. This technique has been further developed into the automated CB system described below.
  18. 8) AUTOMATED CB PREPARATION SYSTEM • The CellientTM system is the first fully automated CB system and the most recent advance in this technology • Cellient automatically recovers small tissue fragments from a specimen container and rapidly delivers them in paraffin for histological sectioning in less than an hour. • The Cellient system works on vacuum-assisted filtration. • visualization of abnormal cells, even when they are in low concentrations, more efficiently than simple sedimentation or HistoGel CBs
  19. • Furthermore, it can be a useful technique to improve the diagnostic accuracy of atypical glandular cells in Papanicolaou tests • Cellient CBs provide comparable results in immunohistochemical determination, in situ hybridization (ISH) and molecular analysis of breast cancer biomarkers to those obtained using formalin-fixed and thrombin CBs
  20. UTILITY 1) CBs are increasingly being used as an adjunct to smears to improve the diagnostic accuracy of FNA cytology • The sensitivity of CBs for FNAs varies from 60% to approximately 90% depending on sampling type, size of specimen and aspiration technique used.Overall improvement and additional information for diagnosis have been observed in 15–55% of cases. • Using morphology alone, CB increases the detection rate of malignancy by 6.5–9% when combined with conventional smears.
  21. 2) The cytological study of effusions is a routine procedure and of great importance in the diagnosis and management of patients. In body fluid specimens, the results of smears and CBs are almost identical in terms of diagnostic yield and sensitivity
  22. 3) The adjunctive use of a single CB slide with LBC increased the detection rate of malignancy by 67% over LBC alone, and the use of ancillary studies on CB further improved the diagnostic accuracy and tumour subclassification
  23. 4) The utility of CBs lies in the availability of diagnostic material for further morphological examination, histochemistry and ICC for better characterization of tumours. In many circumstances, biopsy tissue is not available and a cytological specimen may be the only source available for molecular analysis.
  24. LIMITATIONS 1) Increased turnaround time. 2) Excess material is required to obtain a goodquality cellular pellet, which is not always possible, especially in deep-seated organs. 3) The risk of losing cytological material during tissue processing or sectioning is another drawback because of the small size of the specimen.
  25. 4) Not all specimens are suitable for CB preparation, and a significant volume of CB preparations lack sufficient tumour cellularity for future ancillary testing. 5) All CB techniques are labour intensive and demanding 6) Lastly, in comparison with traditional smear cytology, the CB method adds an extra cost to patient management.
  26. BRONCHIAL WASH
  27. BRONCHIAL WASH Micropapillary variant
  28. PERITONEAL WASH PAX 8 p53
  29. PLEURAL FLUID TTF 1 CK 7
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