Comparison of conventional smear cytology and manual liquid based cytology based on smears from normal oral exfoliated cells

Abstract

Liquid-based cytology (LBC), since its inception in the 1990s, has shown significant advantages over conventional exfoliative cytology. LBC gives better results than conventional method as it not only enhances both sensitivity and specificity, but also provides material for further investigations. However, LBC requires expensive automated devices and materials, which might not be affordable for many cytopathology laboratories in countries with poor resources. In order to formulate an economic cytological procedure with the accuracy of LBC, smears made out of manual liquid based cytology (MLBC) technique was followed in this study and the results were compared with respective conventional cytology smears. To the authors’ knowledge, this is the first comparative study between MLBC and conventional method done for oral cavity in normal buccal mucosa. One hundred apparently normal subjects who reported to the outpatient department were selected after obtaining informed consent from all the subjects. Two Scrapings were made in each patient from the clinically normal appearing buccal mucosa. Both conventional and MLBC smears were stained by routine Papanicolaou technique and evaluated by three independent observers for specimen adequacy, thickness of the smear, uniformity of cell distribution, clarity or resolution of the cells, presence of background artifacts, and staining characteristics of the cells. Each parameter was graded as satisfactory; satisfactory but limited; or unsatisfactory. Number of satisfactory results obtained in MLBC smears was significantly higher than that by conventional smears. After comparison of smears prepared from conventional cytology and manual liquid-based cytology, we conclude that manual liquid-based cytology is both cost effective and also technically sound method with specific and clear results.