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.

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

10. Cytosmears
Suspicious/
Malignant
Cell blocks
Special
stains
IHC
Molecular
testing
FNAC/ Fluids
Benign
Inflammatory
Infectious

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+

20. Cytosmears Cell Block
Immunohistochemistry

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