Fine Needle Aspiration Cytology of Granulomatous Lesions of The Breast A Six-Year Retrospective Study

Abstract

Background: Granulomatous lesions of the breast are uncommon and can mimic malignancy. Fine needle aspiration (FNA) is among the first investigations in such patients. Cytological diagnosis in the absence of granulomas may pose a diagnostic dilemma. The present study outlines the cytological features of such lesions. Methods: This was a 6-year (January 2011 and December 2016) retrospective study. Cases with a biopsy proven diagnoses of granulomatous mastitis having FNA of the corresponding lesion were included in the study. Clinical, radiological and microbiological details were retrieved from the medical records. The cytology slides were reviewed and correlated with clinical and histopathological findings. Result: Thirty-two cases were included in the study. The age range was 22 to 62 years. On cytology, 17 showed well-formed granulomas. One case each of Mycobacterium tuberculosis and Burkholderia pseudomallei were identified by culture. Among the 15 cases with no granulomas, scattered histiocytes and giant cells were seen. Most patients presented with breast lump and fever. Uncommon presentations included peau de orange, skin erythema, induration, nipple retraction and axillary lymphadenopathy. Most lesions were hypoechoic on mammography. Nine cases were clinically suspicious for malignancy while rest were diagnosed as abscess, fibroadenoma or mastitis. Conclusion: In the developing world, tuberculosis and meliodosis can present with granuloma formation. In the breast, these entities can have overlapping features with idiopathic granulomatous mastitis. In the absence of granulomas on cytology, these lesions may be mislabeled as breast abscess. In such cases, the presence of scattered histiocytes and giant cells may aid in diagnosing these lesions.