Comparison Three Cases of Mammary-type Myofibroblastoma

Abstract

Mammary-type myofibroblastoma (MTMF) is a relatively rare benign mesenchymal neoplasma that has been reported in diverse body regions. In this study, we report three cases of MTMF in the breast. Although image findings in each case depicted a variety of images, all showed a benign pattern. Histopathologically, the tumors consisted of spindle cells stained with CD34 and desmin. The pathological subtype defined in the WHO classification is palisading/Schwannian-like pattern in two cases and fibrous/collagenized pattern in the other. The ratio between the amount of spindle and stromal cells may lead to different image findings, suggesting that the diagnosis of MTMF is difficult based on images alone, since there are no characteristic findings. We believe that accurate histopathological examination, including immunohistochemistry, is important for diagnosis.