Role of fine-needle aspiration cytology as an inexpensive tool for diagnosis of idiopathic granulomatous mastitis

Abstract

Introduction: Idiopathic granulomatous mastitis (IGM) is a benign chronic inflammatory disease of the breast. The diagnosis depends on histopathological examination after ruling out all other diseases causing granulomatous lesions. Although diagnosis by cytology is a challenging task, especially in a tuberculosis-prevalent country, it helps in early diagnosis if certain protocols are followed and helps to avoid the complications related to biopsy. Aims and Objective: In this study, 52 cases of IGM were followed retrospectively to analyse the cytological findings, which are helpful for a conclusive diagnosis of the disease. Materials and Methods: An institution-based retrospective observational study conducted over a period of 7 years, and patients with histologically proven cases of granulomatous mastitis were selected for this study. Fifty-two cases were analysed. For cytologic evaluation, parameters evaluated were – (1) presence of granulomas, (2) predominant cell of infiltration, (3) presence of fibrocapillary fragments, (4) presence or absence of caseation necrosis, (5) morphology of multinucleated giant cells and if present, (6) ductal cells – normal or atypical. Statistical Analysis: Conducted in MS Excel and R 4.2.1. Results: Epithelioid cell granuloma is the most consistent finding, as it was present in 90% of cases. Other findings such as neutrophilic infiltrate (76.9%), presence of fibrocapillary fragments (86.5%), absence of caseation necrosis (98.1%) and lack of ductal cell atypia (94.2%) carry significance in diagnosis. Conclusion: Cytological findings such as epithelioid cell granulomas with the absence of caseation necrosis, predominant neutrophilic infiltrates, presence of fibrocapillary fragments and absence of ductal cell atypia when collaborated with special stains for fungus and acid-fast bacilli, will correctly help in diagnosing IGM by fine-needle aspiration cytology.