Purpose: Idiopathic granulomatous mastitis (IGM) is a rare inflammatory pseudotumor. No therapeutic modality has 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 the optimal methods of observation during corticosteroid therapy of IGM.
Methods: The retrospective study included eight 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.
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 a 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 a resection due to severe pain. Seven patients healed without surgery and it took from 4 to 10 months to achieve a cure. The period until confirmation of the disappearance of a mass was the shortest by palpation, followed by contrast magnetic resonance imaging and ultrasonography in that order.
Conclusion: Steroid therapy was effective for the treatment of IGM, which was cured without surgery in seven of eight cases. Ultrasonography was considered an excellent method for evaluating the treatment outcomes.