Role of fine-needle aspiration cytology in tuberculosis of bone.

This study was designed to evaluate the role of fine-needle aspiration cytology (FNAC) in diagnosis of skeletal tuberculosis (TB). In this retrospective study, 20 cases were retrieved over a 10-year period in which a cytologic diagnosis of osseous TB was rendered. The aspirations were performed with a 22-gauge needle attached on a 20-ml syringe after taking into consideration the radiological findings. The cytologic findings were subdivided into the following categories--epithelioid cell granulomas with necrosis, epithelioid cell granulomas without necrosis, and necrosis only. These cases were either with or without AFB positivity. The smears showed epithelioid cell granulomas in 23 cases (85.2%), multinucleate and Langhans' giant cells in 15 cases (55.6%), and inflammatory cells were noted in the background in 15 cases (55.6%). AFB was positive in six cases (22.7%). FNA provides a simple and safe outpatient procedure for the diagnosis of osseous TB and obviates the need of an open biopsy.