Role of Bronchoscopic Cytology in Diagnosis of Pulmonary Lesions.

Objectives: Respiratory cytology specimens such as bronchoalveolar lavage (BAL) and bronchial wash (BW) obtained using a fiberoptic bronchoscope are very useful in detecting or ruling out various inflammatory conditions, infections, and neoplastic lesions. A study was carried out to determine the usefulness of respiratory cytology in the diagnosis of pulmonary lesions and the limitations of cytology if any, and correlate the results of cytology with biopsies wherever possible.

Methods: All bronchoscopic cytology and biopsy specimens received at the pathology laboratory of this tertiary care institute between June 2014 and May 2017 were analyzed. Cytology smears were stained with Leishman's stain, hematoxylin and eosin (H and E), Papanicolaou (PAP), and Ziehl-Neelsen (ZN) stain for all cases and special stains wherever needed. Slides prepared from biopsy specimens were stained with H and E. Immunohistochemistry was used for confirmation and further typing of malignant lesions and diagnosis rendered was compared with the corresponding cytology diagnosis.

Results: A total of 120 specimens of BAL or BW cytology with or without biopsy were analyzed. Thirty-three were diagnosed as non-specific inflammatory lesions. The most common malignancy diagnosed by cytology was adenocarcinoma followed by squamous cell carcinoma. Correlating BAL with biopsy specimens, the sensitivity, specificity, and diagnostic accuracy of BAL were 100%, 88.8%, and 91.6%, respectively. Correlating BW with biopsy specimens, the sensitivity, specificity, and diagnostic accuracy of BW were 85.6%, 85.6%, and 85.6%, respectively.

Conclusions: Accurate diagnosis can be made from the examination of bronchoscopic cytology specimens in pulmonary inflammation, tuberculosis, fungal infections, and malignancies. Combining respiratory cytology with biopsy and ancillary techniques can aid in better subtyping of neoplastic lesions.