Needle Aspiration and Cytology for Suspected Osteoarticular Tuberculosis in Children.

Introduction: Early diagnosis of osteoarticular tuberculosis (OATB) is essential to prevent significant functional disability. There is no single test for diagnosis. Despite an array of investigations available, definitive diagnosis at early stage before starting antitubercular drugs is still a challenge. Materials and Methods: A cross sectional study was carried out between February 2016 and October 2017. All children less than 18 years of age with suspected osteoarticular tuberculosis were included. The cases were subjected to simple needle aspiration from whichever site was accessible. Multiple sample aspirations were done at site of involvement. Smears were prepared from the aspirated material. Results: Ziehl-Neelsen staining for Acid Fast Bacilli (AFB) showed deep pink red rods under light microscopy. Features suggestive of tuberculosis can be seen by May-Grünwald-Giemsa (MGG) staining. Auramine-O staining method of detecting AFB under fluorescent microscope shows the bacilli as greenish yellow slender curved rods in dark background. Fluorescent microscopy has higher sensitivity and comparable specificity. In our study, microbiological confirmation of OATB could be done in 100% cases where the lesion could be accessed for aspiration. The molecular techniques are relatively more expensive and not available everywhere. Conclusion: Meticulous search for AFB in a well stained smear using three different staining methods provides a direct evidence of infection over costly imaging especially in poor patients seen in resource limited settings.