cell block and its utility
TRANSCRIPT
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
• Guided aspiration by C.T or USG allows FNA of lesions
of internal organs like lung, mediastinum, abdominal
and retroperitoneal organs, prostate , etc
• 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
• 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
• 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
Cytosmears
Suspicious/
Malignant
Cell blocks
Special stains IHC Molecula
r testing
FNAC/ Fluids
Benign
Inflammatory
Infectious
• 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 ?
Cell blocks offer the opportunity to examine the
histological structure and allows the use of ancillary
tests Cytology Histopathology Bridge (Cell blocks)
• 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
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
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
• 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?
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
4323
1162709
4. Fluids 458
5. Cell blocks prepared 210
6. Increased cellularity by cell block 40 - 45%
6. Increased diagnostic yield by cell block 15%
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