Angiomatoid fibrous histiocytoma arising in the mediastinum

A case of primary angiomatoid fibrous histiocytoma of the mediastinum is presented in a 59-year-old woman who presented with the symptoms of cough, weight loss, and anemia. Chest radiographic examination revealed the presence of an anterior mediastinal mass adjacent to the superior vena cava. An incomplete surgical resection of the tumor was performed, yielding a 4.0-cm tan-gray tumor. Histologically, the tumor was characterized by a spindle cell proliferation admixed with an inflammatory infiltrate and hemorrhagic cystic areas. Immunohistochemical studies were performed, demonstrating that the tumor cells were positive for CD68 and focally positive for desmin. Other immunohistochemical studies, including cytokeratin, epithelial membrane antigen (EMA), leukocyte common antigen (LCA), CD20, CD30, CD34, CD45RO, S100, and HMB-45, were negative. Currently, the patient remains alive and well 7 months after surgical resection. However, due to the incomplete removal of the tumor, radiation therapy was administered. The present case highlights an important diagnostic problem in mediastinoscopic biopsies of anterior mediastinal lesions. In addition, these "fibrohistiocytic" lesions, though rare, should be included in the differential diagnosis of spindle cell neoplasms of this region.