Sepehr Metanat - Students' Scientific Research Center (SSRC), Tehran University of Medical Sciences, Tehran, Iran
Yekta Soleimani Jobaneh - University of Toronto, Toronto, Ontario, Canada
Maedeh Noori - Young Researchers and Elite Club, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran
Farhood Sadeghi - Students' Scientific Research Center (SSRC), Tehran University of Medical Sciences, Tehran, Iran

Background: Idiopathic granulomatous mastitis (IGM) is a challenging exclusion diagnosis for breast lesions, manifested as benign, chronic inflammation of the breast tissue. Although some evidence suggest that IGM cases are not uniformly distributed worldwide, few investigations have specifically addressed this topic. This study aims to examine the distribution of IGM cases among countries and races/ethnicities based on reported cases. Methods: A review of studies with a report of at least one IGM patient published from ۲۰۱۱ to ۲۰۲۰ inclusive was conducted. The search was performed in MEDLINE, and citations were filtered in two stages by title/abstract and full text. Those cases with a positive growth of pathogens, male granulomatous mastitis and review articles were excluded. Results: Among ۳۶۵ retrieved publications, ۲۱۸ were finally included based on the inclusion and exclusion criteria, comprising ۷۱۶۱ patients from ۳۴ different countries. Turkey, the United States, and China were the countries where the most publications (including case reports) originated. Considering the number of patients within papers, Turkey, Iran, and China were the pioneers. Conclusion: Based on the published literature, some populations seem to be more prone to IGM. Further investigations may reveal the genetic and environmental factors associated with this disease in different geographic areas.

Idiopathic granulomatous mastitis, Granulomatous Mastitis, Ethnicity, Race, Distribution