[Aneurysmatic fibrous histiocytoma: case report and reivew of the literature].

A case of aneurysmal fibrous histiocytoma is described. The patient is a 26-year-old man with a reddish nodule on the back, recently presenting a volume increase. The tumor was composed of fascicles of short spindle cells, histiocyte-like and inflammatory cells, and blood-filled spaces, mimicking vascular channels but lacking an endothelial lining. Immunohistochemical analysis (performed with the following monoclonal antibodies: smooth muscle actin, vimentin, desmin, CD-31, CD-34, CD-68) showed only vimentin positively on neoplastic cells. We discuss the differential diagnostic hypotheses and review the literature on this subject.