Liquid-based and conventional cytology for bronchial washings/bronchoalveolar lavages in the diagnosis of malignancy - An institutional experience

BACKGROUND: Liquid-based cytology (LBC) has been developed as an alternative for conventional cytology (CC) in cervical smears. It is now increasingly being used all over the world for cervical cancer screening. However, its role and diagnostic accuracy in bronchial wash (BW)/bronchoalveolar lavage (BAL) specimens remains undetermined. AIMS: To assess and compare the diagnostic performance and accuracy of LBC with CC for detecting malignancy in bronchial specimens. SETTINGS AND DESIGN: This was a retrospective analytical hospital-based study. MATERIALS AND METHODS: Bronchial specimens (BW/BAL) received over a period of 4.5 years were reviewed. The samples were processed by CC from June 2010 to September 2012 (2.25 years) and by LBC from October 2012 to December 2014 (2.25 years). Data were retrieved from the records of cytology laboratory and compared among both the groups. Detection rate for histologically or cytologically verified samples was calculated. RESULTS: A total of 559 cases verified by histological and cytological follow-up were evaluated. These included 247 CC cases and 312 LBC cases. The positive diagnostic rate for malignancy in CC was 28.6% whereas that for LBC was 32.9%. The negative diagnostic rates were 66.5% and 66.3% for CC and LBC, respectively. However, unsatisfactory rates had shown a good reduction from 4.4% in CC to 0.6% after LBC introduction. The smears showed more homogeneous distribution of cells with elimination of obscuring factors such as blood, inflammation, and mucus. CONCLUSIONS: The diagnostic accuracy of LBC was slightly better than CC. The unsatisfactory rates showed reduction in LBC preparation. Thus, LBC is a viable alternative to CC and has the advantages of standardization of preparation with decrease in unsatisfactory rates.