Evaluation and comparison of conventional brush-based and centrifugation liquid-based cytopathology

Background: Brush cytopathology is a traditional method of collecting shed cells by scrapping off the mucosal surface of the oral cavity. Liquid-based cytopathology by centrifugation is a technique that causes the cells to be suspended in a monolayer enabling better morphological assessment. Aims: The aim of this study is to compare the efficacy of conventional brush cytopathology and centrifugation-based liquid cytology (CBLC) in oral lesions after staining with rapid Papanicolaou (PAP) stain. Materials and Methods: Forty cases of oral lesions comprising normal mucosa (n = 10), hyperkeratotic lesions (n = 11), ulcerated lesions (n = 15), and inflammatory lesions (n = 14) were selected. Two smears were obtained from the lesion using a cytological brush. One was spread on the slide using conventional technique, fixed immediately in 95% ethyl alcohol. The second sample was suspended in prepared fixative solution for 10 min and then spun in centrifuge for 10 min. The supernatant was poured off, and the obtained cell pellet was used to prepare a smear by sedimentation and left to dry overnight. Both the smears were stained by rapid PAP (Biolabs Pvt. Ltd.). The stained smears were compared statistically for cellular yield, cell distribution, cell morphology, and background noise (presence of blood, inflammatory cells, microbial colonies, and artifacts). Results and Conclusion: The efficacy and quality of the smears based on the liquid-based preparations indicated its superiority in obtaining a higher yield of cells and clearer background. The increased cellular yield in liquid-based preparations also showed increased clumping and overlapping of cells which proved as a drawback for CBLC.