Context: Liquid-based cytology.
Aims: Utility of liquid-based cytology (LBC) was compared to conventional smear cytology in ultrasound-guided fine-needle aspirates of abdominal masses.
Settings and design: This was a prospective comparative study conducted in collaboration with surgery and pediatrics surgery departments of our institute.
Subjects and methods: Thirty patients presenting with evidence of abdominal mass were enrolled for the study and underwent fine-needle aspiration cytology. The material was processed for the preparation of conventional smears and residual material was rinsed into cytolyt for LBC by Thin Prep method and into cell block fluid. The smears prepared from both the methods were compared by two independent and experienced pathologists for adequacy, cellularity, architectural pattern, cytoplasmic preservation, nuclear preservation, and background.
Results: : Cellularity was frequently higher in the conventional smears than on Thin Prep slides (P value = 0.025). Recognition of architecture was better on the conventional smears (P value = 0.001). Cytoplasm was better preserved on the conventional smears (P value = 0.001) but difference in the preservation of nuclear details was not statistically significant on slides prepared from both the techniques. The background of Thin Prep slides is significantly cleaner than direct smears (P value = 0.001). Non epithelial elements such as mucin and neurofibrillary tangles were better preserved on direct smears (P value = 0.001) but diagnostic accuracy of both the methodologies showed no statistically significant difference (P value = 0.226).
Conclusions: The Thin Prep technique utilizes expensive equipment and reagents. It also generates certain morphological artefacts in slides with which a cytologist needs to get familiar. When used in isolation, it may not consistently provide any added advantage in the diagnosis of such lesions and should be used as an adjunct to conventional smears. It may be preferred in situations where material has to be transported for processing or is required for ancillary tests.
Keywords: Abdominal masses; FNA; Thin Prep; liquid-based cytology.