Imaging Findings of Metastatic Breast Malignant Fibrous Histiocytoma: A Case Report

According to the most recent WHO classification (2002 edition), soft tissue malignant fibrous histiocytoma (MFH) is considered to be an undifferentiated pleomorphic sarcoma. MFH is the most common somatic sarcoma involving deep soft tissues (1). The most frequent primary sites of MFH are the lower limbs (49%), upper limbs (19%), and abdominal cavity or retroperitoneum (16%) of adults (2). MFH of the breast is extremely rare, only 65 cases have previously been reported so far (3). And most of the case reports were about histopathological diagnosis of primary breast MFH or therapeutic strategy and prognostic factors (3). In recent study, there was an attempt to describe the imaging feature of primary breast sarcoma (4), but including only one breast MFH among 24 breast sarcoma cases. And individual imaging findings of the specific types of breast sarcoma were not separately described in this study (4). Furthermore most of the reports of breast MFH are focused on primary breast MFH, so little is known about metastatic breast MFH. In this case report, we describe imaging findings of metastatic breast MFH from left upper extremity, including breast MRI and other breast imaging modalities such as mammography and ultrasound.