Yamada Rin, Horiguchi Shin-ichiro, Yamashita Toshinari, Kamisawa Terumi
Department of Pathology, Tokyo Metropolitan Komagome Hospital, Bunkyo-ku, Tokyo, Japan.
Department of Breast Surgery, Tokyo Metropolitan Komagome Hospital, Bunkyo-ku, Tokyo, Japan.
BMJ Case Rep. 2016 Mar 23;2016:bcr2016214870. doi: 10.1136/bcr-2016-214870.
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.
IgG4相关疾病（IgG4-RD）的特征是血清IgG4浓度升高、密集的淋巴浆细胞浸润、席纹状纤维化以及组织中IgG4阳性浆细胞增多。这种全身性疾病可同时发生于多个器官，但IgG4相关乳腺炎极为罕见。我们报告一例IgG4相关乳腺炎病例，影像学上认为主要由导管内成分构成，表现为乳腺癌，需要与黏膜相关淋巴组织（MALT）淋巴瘤进行组织学鉴别。乳腺肿块经类固醇治疗后消失。当患者出现乳腺肿块时，无论是否存在IgG4-RD，除乳腺癌外还应考虑IgG4相关乳腺炎。如果组织学检查发现密集的淋巴浆细胞浸润，除恶性淋巴瘤外还应怀疑IgG4相关乳腺炎，并应确认缺乏单克隆性。为避免不必要的手术或化疗，有必要了解并准确诊断IgG4相关乳腺炎。
