Breast Cancer and IgG4-related Sclerosing Mastitis on the Same Side of the Mammary Gland—A Case Report—

Key Points

• The case aims to explore the coexistence of breast cancer and IgG4-related sclerosing mastitis in the same gland.
• Case report involving a 59-year-old female with autoimmune pancreatitis and IgG4-related disease.
• Diagnostics included PET-CT, MRI, and needle biopsy.
• Surgical intervention consisted of total mastectomy and sentinel lymph node biopsy.
• Diagnosed with stage I breast cancer and IgG4-related sclerosing mastitis.
• Post-surgery treatment involved aromatase inhibitor administration for breast cancer.
• Monitoring of IgG4-related condition showed a reduction in other lesions without steroid use.