Liquid Based Cytology
Conventional cytology lacks precision due to one or more of the following reasons,
- Pap smears/FNAC are admixed with mucus/blood.
- Multilayering of cells obscures diagnostic fields.
- Cellular morphology very often changes during collection and transport to the laboratory.(Atrophied cellularity)
- Body Fluids (like CSF) with low cellularity when processed with centrifugation techniques often give negative results.
- Pap smears are often reported with guarded diagnosis with the favorite line inscribed as ’Inflammatory smear, please repeat after treating infection in many samples. Hence, patients are called many times for collecting samples to have correct diagnosis.
- Problem of over reporting (false positive cases) leads to surgical intervention.
To overcome these problems Liquid-Based Cytology Technique is a necessary welcome. It is being adopted in many countries for Gynae/Non-Gynae samples. Here, for example in Pap smear, instead of making smears on slide the spatula is immersed in Liquid(preservative-an alcoholic content) and sent to the laboratory. The liquid is processed for removing obscuring material, mucus and blood; with clearing solution and centrifuged by conventional centrifugation for collecting cells. Supernatant is discarded and pellicle so formed is admixed with cellular base solution which is finally transferred to clean slide by pasteur pipette. Slides are dried at 40 degree (incubator) and stained by conventional techniques having monolayered cellularity.
The cost has been considerably reduced with newer manufacturers supplying kits at reduced price and omitting with automated technology adopted in its initial years. We see bright future of liquid based cytology helping in diagnosing lethal diseases early and with confidence.
