Cell block and its utility
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Cell blocks provide tissue fragments from FNA specimens that are processed into paraffin blocks. This allows examination of histological structure and use of ancillary tests like immunohistochemistry. Cell blocks increase diagnostic sensitivity and specificity compared to cytology alone. They require minimal effort and preserve tissue for second opinions without losing the original smears. The document discusses FNAC and cell block techniques, materials used, advantages like increased cellularity and diagnostic yield, and importance of clinical information for optimal diagnosis.
Cell block and its utility
- 1. CELL BLOCK AND ITS UTILITY IN CYTOPATHOLOGY Dr Prakriti Shukla, Department of Pathology, BMHRC
- 2. Fine needle aspiration cytology (FNAC) • FNAC is the study of cellular samples obtained through a fine needle under negative pressure • It is useful in palpable lesions of thyroid, lymph nodes, salivary glands, breast and subcutaneous tissues
- 3. • Guided aspiration by C.T or USG allows FNA of lesions of internal organs like lung, mediastinum, abdominal and retroperitoneal organs, prostate , etc
- 4. • Relatively painless and inexpensive • Provides unequivocal diagnosis (sensitivity and specificity ≥ 90%) • Highly suitable in debilitated patients and multiple lesions • Low risk of complications • Easily repeatable
- 5. Sample collection Sample preparation Sample analysis Collection Preparation Analysis
- 6. • Proper history, clinical examination and radiological findings • Site must be clearly specified • In deep seated swellings, the site must be properly marked after examining the patient • Deeper swellings should be approached by guided FNA • If specimen is sputum, 3 to 5 consecutive days sputum samples should be examined for diagnostic accuracy Instructions before Aspiration
- 7. • For fluid cytology, 20–30 ml fluid is required for cytodiagnosis • If the entire specimen tapped cannot be sent to the laboratory, a representative sample from the bottom part of the fluid should be sent to the laboratory • Smearing must be performed properly (reduces crushing artefacts) • Avoid admixture with blood while performing FNA • Adequate number of slides must be prepared from each patients with proper labelling
- 8. Equipments required for FNAC
- 11. • Cell blocks are micro biopsies embedded in paraffin that broaden the diagnostic value of cytology specimens and are complementary to cytology preparations • It employs retrieval of small tissue fragments from FNA specimen which are processed to form a paraffin block What is a cell block ?
- 12. Cell blocks offer the opportunity to examine the histological structure and allows the use of ancillary tests Cytology Histopathology Bridge (Cell blocks)
- 13. • Acquisition of tissue for cell block can increase both diagnostic sensitivity and specificity (through both cellular morphology and ancillary testing) • It requires minimal effort and is extremely cost efficient. • Moreover, tissue preserved in cell block can be readily shared for second opinions and research without fear of losing the original diagnostic smear specimen Need for Cell Block
- 14. Material required for cell block
- 15. Specimens FNAC/FNAB SPUTUM EFFUSION FLUIDS URINE LAVAGES & WASHINGS
- 16. 1. Plasma thrombin method 2. Fixed sediment method 3. Bacterial agar method 4. Technique using alcohol, acetone and paraffin 5. Compact technique 6. Cell blocks from Millipore Methods of cell block preparation 7. Histogel method 8. Gelatin embedding 9. Celloidin bag 10.Scraping of cytology smears 11.Automated preparation 12.Albumin method
- 17. 1. CB is simple , reproducible and readily available in routine labs 2. Increased cellularity 3. Better morphological and architectural patterns 4. Additional yield of cells, thereby increasing diagnostic yield 5. Unlimited storage of the sample 6. Application of ancillary studies (IHC and molecular testing) Advantages
- 18. Cytosmears v/s Cell Block Lymphocytic effusion
- 19. CA PROSTATE - PLEURAL EFFUSION CS CB CALRETININ - PSA+
- 21. • Following must be provided 1. Proper history 2. Clinical findings 3. Radiological findings 4. Site of FNA 5. Adequate sample • The morphological features may vary with the site of FNA and have to be correlated with the site of aspiration and other investigations for a meaningful diagnosis What Pathologist wants from Clinician?
- 22. Annual Cytopathology Data (2014) (FNA & Cell block) SN CYTOLOGICAL DATA No. 1. Total cytological samples 676 2. FNAC 218 3. Site 1. Breast 2. Thyroid 3. Lymph nodes 4. Guided abdominal FNA 5. Others 43 23 116 27 09 4. Fluids 458 5. Cell blocks prepared 210 6. Increased cellularity by cell block 40 - 45% 6. Increased diagnostic yield by cell block 15%
- 23. 1. FNAC is a useful diagnostic tool with sensitivity and specificity of more than 90 % 2. Cell block further adds to the diagnostic accuracy 3. Clinical information is must for optimal quality of diagnosis Take home message !!! FNA/CELL BLOCK MORPHOLOGICAL INTERPRETATION CLINICAL INFORMATION
- 24. Thankyou