Tuberculosis is a contagious, infectious disease caused by Mycobacterium Tuberculosis. Due to its complex immunological response, chronic progression and the need for long-term treatment, tuberculosis has always been a major health burden.
Aims: To study cytomorphological features of all cases of tuberculosis diagnosed on FNA smears, and to compare the positivity by fluorescent staining for mycobacterium Tuberculosis with different cytomorphological features.
Material & methods: The study was carried out at the Department of Pathology, P.D.U. Medical College, Rajkot, during the period of two years from September 2016 to August 2018. Total 461 cases diagnosed cytomorphologically as tuberculousis were included in the study. Cases were divided into three patterns based on Cytomorphologic features, namely Granuloma only, Granuloma with caseous Necrosis and Caseous Necrosis without Granuloma, with or without other inflammatory cells. Each case was also studied by fluorescent staining for Tubercle bacillilli. The positivity in different patterns of cytomorphologic features was compared.
Results: Among 461 cases studied, age of patients ranged from 9 months to 85 years with a mean age of 37 years and there was male predominance. Most common presentation of was cervical lymphadenopathy. The commonest cytomorphological feature was granuloma with caseous necrosis. Overall positivity for Tubercule Bacilli was 46.4%. Maximum positivity was seen in caseous necrosis without granuloma pattern, indicating increased bacterial load in such cases.
Conclusion: Fine needle aspiration cytology (FNAC) is a simple, effective and safe modality for obtaining a representative material from any palpable/non palpable lesions (under imaging guidance). Cytomorphological features of tuberculosis are well established, so it can be easily diagnosed on FNA smears. Fluorescent staining of Tubercle Bacilli is well established technique and has got advantage that bacilli are detected readily on low power objective due to sharp contrast & fluorescence. Cases in which granulomas are not seen and only caseous necrosis with or without other inflammatory cells are seen are sometimes difficult to diagnose as tuberculosis cytomorphologically. Such cases show maximum positivity for tuberculous bacilli thus helping in diagnosis in many cases.