Cell block and its utility

CELL BLOCK AND

ITS UTILITY IN CYTOPATHOLOGY

Dr Prakriti Shukla, Department of Pathology, BMHRC

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

Sample collection Sample preparation

Sample analysis Collection

Preparation

Analysis

• 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

Equipments required for FNAC

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

Material required for cell block

Specimens

FNAC/FNAB SPUTUM

EFFUSION FLUIDS

URINE

LAVAGES & WASHINGS

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

Cytosmears v/s Cell Block Lymphocytic effusion

CA PROSTATE - PLEURAL EFFUSION

CS CB

CALRETININ - PSA+

Cytosmears Cell Block

Immunohistochemistry

• 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

Thankyou