Idiopathic granulomatous mastitis (IGM) is a rare benign infectious disease of the breast, commonly presenting with a unilateral breast mass. Since GM's clinical presentation and imaging can be very similar to breast cancer, diagnosing GM can be challenging. So far, various reports have demonstrated the probable correlation and co‐occurrence of granulomatous mastitis and breast cancer. This report presents a 38‐year‐old female with invasive ductal carcinoma, previously diagnosed as IGM.