GRANULOMATOUS MASTITIS IS NOT ALWAYS TUBERCULAR: ROLE OF FINE NEEDLE ASPIRATION CYTOLOGY IN EVALUATION OF GRANULOMATOUS MASTITIS

Abstract

INTRODUCTION AND OBJECTIVES:
 Granulomatous mastitis is rare chronic inflammatory benign breast lesion, which clinically and radiologically resembles carcinoma breast thus creating a diagnostic dilemma. The term granulomatous mastitis includes two broad categories namely specific granulomatous mastitis for which aetiological factors can be defined such as infectious causes like Mycobacterium tuberculosis, blastomycosis, cryptococcosis, histoplasmosis, actinomycosis and filarial infection. Other factors include association with autoimmunue diseases such as Wegner’s granulomatosis and giant cell arteritis and there are other rare causes such as include duct ectasia, foreign body reaction and fat necrosis which also leads to granulomatous lesions of breast.
 Cytological features of granulomatous mastitis(GM) have not been widely discussed and described in literature, so through this study we have made an attempt to thoroughly discuss cytological spectrum of granulomatous mastitis.
 MATERIALS AND METHODS:
 A retrospective study was performed over a period of four years from 2016 to 2019. A total of 465 cases of breast lump reported to cytopathology section out of which 24 cases of GM diagnosed on FNAC were included in our study. Results of Erythrocyte sedimentation rate (ESR) and Mantoux test along with TB-PCR were recorded. FNAC slides were retrieved pertaining to study period.
 Granulomatous lesions of breast were further categorized broadly into IGM/ NGM, granulomatous mastitis without caseous necrosis and tubercular mastitis where diagnosis were made definite on basis of demonstration of AFB or positive TB-PCR .
 RESULTS:
 Patient age ranged from 23 years to 55 years with the mean age of 36.6 years with maximum of patients falling in second decade followed by third decade. Granulomatous lesions were broadly categorized into Idiopathic/ Non specific granulomatous mastitis(11 cases,45.8%), GM with caseous necrosis(8 cases, 33.3%) and tubercular mastitis(5 cases, 20.9%). Histopathology was available in 7 cases(29.2%). TB-PCR was sent in all cases of granulomatous mastitis diagnosed on cytology and was positive in 10 cases(41.7%).
 CONCLUSION:
 Idiopathic granulomatous mastitis and tubercular mastitis are rare inflammatory diseases of breast which mimic malignancy clinically and radiologically. FNAC plays important role in diagnosis of granulomatous diseases of breast and also their differentiation from malignant tumors. Tubercular mastitis needs to be differentiated from IGM since treatment options are different in both the cases. Cytopathology plays an important role in differentiationg both the diseases supplemented by radiological and microbiological investigations.
 The present study thus highlights the importance of FNAC as an infalliable tool in diagnosis of granulomatous mastitis and its differentiation from neoplastic lesions of breast thus avoiding time consuming histopathological work up of cases.