barw Judi Clinical Journal 3105-4102 2 1 2026 06 18 Coexisting Granulomatous Mastitis and Breast Cancer: A Systematic Review 34 43 10.70955/JCJ.2026.05 eng Berun A. Abdalla Scientific Affairs Department, Smart Health Tower, Madam Mitterrand Street, Sulaymaniyah, Kurdistan Region, Iraq 0000-0001-5638-4128 Zuhair D. Hammood Department of Surgical Oncology, Tikrit Teaching Hospital, College of Medicine Street, Tikrit, Saladin, Iraq Diyar Jaafar Hama Rashid College of Medicine, University of Sulaimani, Zanko Street, Sulaymaniyah, Kurdistan Region, Iraq Las L. Hussain Scientific Affairs Department, Smart Health Tower, Madam Mitterrand Street, Sulaymaniyah, Kurdistan Region, Iraq Sabah J. Hasan Scientific Affairs Department, Smart Health Tower, Madam Mitterrand Street, Sulaymaniyah, Kurdistan Region, Iraq Abdulla D. Ahmad Scientific Affairs Department, Smart Health Tower, Madam Mitterrand Street, Sulaymaniyah, Kurdistan Region, Iraq Sasan M. Ahmed Kscien Organization for Scientific Research (Middle East Office), Hamdi Street, Sulaymaniyah, Kurdistan Region, Iraq Shewaz T. Latif Department of Ophthalmology, Shahid Dr. Aso Hospital, Sulaymaniyah, Kurdistan Region, Iraq Hawdang A. Sidiq Scientific Affairs Department, Smart Health Tower, Madam Mitterrand Street, Sulaymaniyah, Kurdistan Region, Iraq Sumaya Sabah Abdulrahman Scientific Affairs Department, Smart Health Tower, Madam Mitterrand Street, Sulaymaniyah, Kurdistan Region, Iraq Gashbeen M. Fatah Department of Laboratory, Anwar Sheikha Medical City, Zagros Street, Sulaymaniyah, Kurdistan Region, Iraq Danyar K. Abdulla Scientific Affairs Department, Smart Health Tower, Madam Mitterrand Street, Sulaymaniyah, Kurdistan Region, Iraq 2026 05 26 Introduction: Granulomatous mastitis (GM) is a rare inflammatory breast disease that mimics carcinoma. GM can coexist with breast cancer (BC), though the relationship remains unclear. This systematic review aims to examine the coexistence of GM and BC, focusing on the clinicopathological features of synchronous and metachronous cases. Methods: A systematic search of PubMed/MEDLINE and Google Scholar, up to the 30th November 2025, identified studies reporting individual patient-level data. Inclusion criteria were: (1) patients diagnosed with both BC and GM (concurrently or sequentially); (2) histopathological or imaging confirmation of both conditions. Exclusion criteria were: (1) animal studies; (2) conference abstracts; (3) non-recommended journal publications; and (4) non-English papers. Descriptive statistics were used to summarize categorical variables as frequencies and percentages, and continuous variables as means or medians with ranges. Results: Nineteen studies (23 female patients; median age of 42 years) were included. Most of the cases were premenopausal 17 (74.0%). Synchronous coexistence occurred in 15 (65.2%), with ipsilateral involvement in 11 (73.3%) of these. Granulomatous mastitis preceded BC in 6 (26.1%) (median interval 3 years), and BC preceded GM in 2 (8.7%). Core needle biopsy diagnosed GM in 9 (39.1%) and BC in 14 (60.9%); excisional biopsy was required in 7 (30.4%) of GM cases. Breast cancer treatment included mastectomy in 11 (47.8%) and breast-conserving surgery in 9 (39.1%). Follow-up ranged from 2–53 months. Conclusion: Granulomatous mastitis and BC can coexist, with GM potentially masking malignancy. Clinicians should maintain a low threshold for repeat biopsy in refractory cases.