櫻井 健一, 松尾 定憲, 榎本 克久, 小倉 道一, 北島 晃, 谷 眞弓, 天野 定雄

Kenichi SAKURAI, Sadanori MATSUO, Katsuhisa ENOMOTO, Michitaka OGURA, Akira KITAJIMA, Mayumi TANI, Sadao AMANO

日本大学外科学系乳腺内分泌外科分野

Breast and Endocrine Surgery, Nihon University

キーワード :

【Background】
Idiopathic granulomatous mastitis （IGM） is a rare inflammatory pseudo-tumor. Although it is benign entity, IGM clinically mimics breast cancer in terms of physical and radiological findings, often leading to disastrous consequences. And therapeutic modality has not been established because of the rareness of this disease. The aim of this study was to investigate the clinical course of IGM treated with corticosteroid, and to evaluate methods of optimal observation during corticosteroid therapy of IGM.
【Methods】
A retrospective study included 8 women who met the required histological criteria of IGM. The clinical data of the presentation, histopathology, and management were analyzed by reviewing the medical records. Treatment outcomes of steroid therapy were evaluated by palpation, ultrasonography, and MRI. Palpation and ultrasonography were carried out every month, while MRI was done every other month after disapperance of a mass was confirmed by palpation until disappearance was reconfirmed by imaging.
【Results】
The mean age of the patients was 44.8 years （range, 28-75 years） and all patients complained of a breast mass. Seven of them had pain. All of them underwent core needle biopsy and were diagnosed as having IGM. Five took prednisolone orally and three received prednisolone plus antibiotics, one patient of the latter group underwent resection due to severe pain. Seven patients healed without surgery and it took four to 10 months for a cure. The period until confirmation of disappearance of a mass was the shortest by palpation, followed by contrast MRI and ultrasonography in that order.
【Conclusion】
Steroid therapy was effective for IGM, which was cured without surgery in seven of eight cases. Ultrasonography was considered an excellent method for evaluation of treatment outcomes.