Cytomorphological patterns in bronchoalveolar lavage in the diagnostic evaluation of pulmonary diseases

Bronchoalveolar lavage (BAL) cytology is a well-established diagnostic tool for respiratory tract lesions. The analysis of cellular patterns in BAL cytology provides useful information about infectious, inflammatory, and neoplastic lung diseases. This study aimed to analyze bronchoalveolar lavage fluid to investigate various cellular patterns in BAL cytology in different pulmonary diseases.

This retrospective study was conducted in the Department of Pathology and included BAL cytology samples from 182 patients between January 2022 and July 2023.

Of the 182 cases, 116 (63.7%) were male and 66 (36.3%) were female. Thirty-seven (20%) cases showed a predominantly neutrophilic cellular pattern, while 61 (33.5%) showed a lymphocytic pattern. Two (1%) cases showed a mixed cellular pattern, including eosinophils. In 32 (17.5%) cases, patterns indicating specific aetiology were identified, the most common being AFB-positive granulomatous inflammation (4.3%), followed by fungal hyphae (1.6%). Malignant cells were seen in 15 (8.2%) cases, with the most common pattern being cells arranged in an acinar pattern, indicative of adenocarcinoma. A rare case of pulmonary alveolar proteinosis was diagnosed based on the presence of PAS-positive extracellular granular to globular material in cytology.

In the era of minimally invasive procedures, BAL cytology analysis stands out as a valuable tool for diagnosing various lung diseases. It aids in the diagnostic workup for many diseases, including those of tubercular, fungal, and neoplastic aetiology. Combining clinical details, radiological information, and BAL cytology can help provide a definitive diagnosis and avoid invasive procedures.