IgG4-related mastitis, a rare disease, can radiologically and histologically mimic malignancy.

Abstract

IgG4-related disease (IgG4-RD) is characterised by high serum concentrations of IgG4, dense lymphoplasmacytic infiltrates, storiform fibrosis and increased IgG4-positive plasma cells in tissues. This systemic disease occurs in various organs metachronously, but IgG4-related mastitis appears extremely rare. We report a case of IgG4-related mastitis, radiologically considered to represent breast cancer mainly composed of intraductal component and requiring histological differentiation from mucosa-associated lymphoid tissue (MALT) lymphoma. The breast mass disappeared with steroid therapy. When patients have a breast mass, regardless of the presence or absence of IgG4-RD, IgG4-related mastitis should be considered in addition to breast cancer. If histological findings show dense lymphoplasmacytic infiltrates, IgG4-related mastitis should be suspected in addition to malignant lymphoma, and lack of monoclonality should be confirmed. To avoid unnecessary surgery or chemotherapy, knowledge and accurate diagnosis of the entity of IgG4-related mastitis is necessary.

• Authors: Rin Yamada, Shin-ichiro Horiguchi, Toshinari Yamashita, Terumi Kamisawa
• Journal: BMJ case reports (BMJ Case Rep) Vol. 2016 (Mar 23 2016) ISSN: 1757-790X [Electronic] England
• PMID: 27009197 (Publication Type: Case Reports, Journal Article)
• Copyright: 2016 BMJ Publishing Group Ltd.

Chemical References

• Immunoglobulin G
• Steroids

Topics

• Aged
• Diagnosis, Differential
• Female
• Humans
• Immunoglobulin G (blood)
• Mastitis (diagnostic imaging, drug therapy, pathology)
• Rare Diseases (blood, diagnostic imaging, drug therapy, pathology)
• Steroids (therapeutic use)
• Treatment Outcome