Cytomorphological findings in confirmed cases of tubercular lymphadenitis

Tuberculosis (TB) remains a major health problem, especially in the developing countries. Fine-needle aspiration cytology is the first line of investigation for tubercular lymphadenitis as it is easy to perform, less invasive, quick, and economical. The typical cytopathological features of tuberculosis TB include epithelioid cell granulomas with Langhans giant cells and caseous necrosis. The present study aimed to evaluate the cytomorphological features of newly diagnosed cases of tubercular lymphadenitis confirmed by GeneXpert. This was a retrospective study in which all fine-needle aspirates from newly diagnosed cases of tubercular lymphadenitis confirmed by GeneXpert over a 1-year period from July 2022 to July 2023 were included in the study. The May–Grunwald–Giemsa stained smears from these aspirates were categorized into three patterns-epithelioid cell granulomas with necrosis, epithelioid granulomas without necrosis, and necrosis only. The granulomas were further categorized into well-formed, ill--formed, and splintered. The background of the aspirate which included a reactive lymphoid background, lymphocytes, eosinophils, and neutrophils was tabulated for all the cases. Out of the three cytomorphological patterns, epithelioid granulomas with necrosis were the most predominant (67.5%), followed by necrosis only (20.8%) and granulomas without necrosis (11.6%). An acid-fast bacilli (AFB) positivity of 53.3% (64 cases) was seen on the Ziehl-Neelsen stain. Well-composed, poorly formed, and splintered granulomas were seen in 55 (57.9%), 42 (44.2%), and 21 (22.1%) cases, respectively. Neutrophils were the most common background population (42, 35%) followed by lymphocytes (36, 30%). Reactive lymphoid cells and eosinophils were seen in 12 (10%) and 3 (2.5%) cases, respectively. Fine-needle aspiration cytology is a rapid inexpensive minimally invasive test for tubercular lymphadenitis as epithelioid cell granulomas along with caseous necrosis are highly suggestive of TB. However, manual acid-fast AFB detection has a low sensitivity as is illustrated in the present study where only AFBwas demonstrated in only 53.3% of cases.