Cytological and Clinical Insights into Tuberculous Mastitis: A Retrospective Analysis Using FNAC and CBNAAT

Introduction: Tuberculous mastitis, a rare extrapulmonary tuberculosis manifestation, often mimics breast malignancy, complicating diagnosis in high-burden regions like India. This study analyzed the cytomorphological spectrum of tuberculous mastitis using fine-needle aspiration cytology (FNAC) and correlated findings with Cartridge-Based Nucleic Acid Amplification Test (CBNAAT) results. Methodology: A retrospective observational study was conducted at GMERS Medical College, Gandhinagar, India, analyzing FNAC data from 60 patients with clinical or radiological suspicion of tuberculous mastitis. Cytological features (epithelioid granulomas, necrosis, giant cells) were assessed using Hematoxylin & Eosin and Papanicolaou stains. Residual aspirates (needle wash/remaining aspirate after slide preparation, 0.5–2.0 mL) were subjected to CBNAAT for Mycobacterium tuberculosis detection. Demographic, clinical features were described and statistical analyses (chi-square test) were performed using SPSS v26.0. Results: Mean patient age was 32.9 ± 9.5 years, with a female predominance (96.7%). Left-sided breast involvement (61.7%) and pain (70.0%) were common. Cytology revealed epithelioid cells (86.7%), necrosis (80.0%), and granulomas (60.0%). CBNAAT was positive in 33/60 cases (55.0%), with a significant association between granuloma presence and CBNAAT positivity (chi square is 4.95, p 0.026). Conclusion: FNAC remains the cornerstone of tuberculous mastitis diagnosis but its integration with CBNAAT offer a rapid and reliable approach to a challenging clinical entity. Granulomas on cytology are a key marker and, when correlated with CBNAAT, can facilitate early antitubercular therapy, minimizing diagnostic delays and unwarranted surgical interventions. Prospective studies are needed to validate these findings and optimize diagnostic protocols.