Idiopathic granulomatous mastitis: a diagnostic dilemma for the breast radiologist

BACKGROUND Idiopathic granulomatous mastitis is a chronic inflammatory disease of the breast, which is often difficult to differentiate both clinically and radiologically from infectious aetiologies such as tuberculosis, fungal infections, and also from malignancy, thus posing a diagnostic dilemma. We present a pictorial review of the commonly encountered imaging findings in idiopathic granulomatous mastitis on mammography and ultrasound. MATERIALS AND METHODS Mammographic and ultrasound findings of histopathologically proven cases of granulomatous mastitis are discussed. CONCLUSION Idiopathic granulomatous mastitis has varied and non-specific appearances on ultrasound and mammography. Histopathology is essential to establish diagnosis. TEACHING POINTS • Idiopathic granulomatous mastitis often poses a diagnostic dilemma for the radiologist by mimicking malignancy. • It has varied and non-specific appearances on mammography and ultrasound. • Histopathology is mandatory to establish the diagnosis and decide management.