Tehran University of Medical Sciences Acta Medica Iranica 0044-6025 62 6 2024 12 31 378 380 EN Marzieh Mohammadi Zavieh Breast Disease Research Center (BDRC), Cancer Institute, Tehran University of Medical Sciences, Tehran, Iran. Ramesh Omranipour Breast Disease Research Center (BDRC), Cancer Institute, Tehran University of Medical Sciences, Tehran, Iran. AND Department of Surgical Oncology, Cancer Institute, Tehran University of Medical Sciences, Tehran, Iran Sadaf Alipour Breast Disease Research Center (BDRC), Cancer Institute, Tehran University of Medical Sciences, Tehran, Iran. AND Department of Surgery, Arash Women’s Hospital, Tehran University of Medical Sciences, Tehran, Iran. Maryam Sarkardeh Breast Disease Research Center (BDRC), Cancer Institute, Tehran University of Medical Sciences, Tehran, Iran.AND3 Department of Surgery, Arash Women’s Hospital, Tehran University of Medical Sciences, Tehran, Iran. AND Department of Surgery, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran. 2024 05 11 2025 01 19 Idiopathic Granulomatous Mastitis (IGM) is an inflammatory and benign breast disease that can mimic a wide range of breast diseases (from infection to breast cancer (BC)). IGM affects women in the childbearing age and is more prevalent in Asia. According to similarity of IGM and BC presentation and different treatment pathways, it is important to distinguish between these two diseases. We present three cases; the first one is a 42-year-old woman with IGM 2 years after treatment of a stage two breast carcinoma; and the second and third one is a 46-year-old and 41 years old ladies with breast cancer 4 and 13 years after being diagnosed with IGM. Although the occurrence of IGM and cancer in an individual patient is rare, physicians should be aware of this possibility. https://acta.tums.ac.ir/index.php/acta/article/view/11104