Solitary fibrous tumor of the mesentery

We report a solitary fibrous tumor of the abdominal cavityt that presented as a encapsulated mass attached to the mesentery in a 33-yr-old man. Histologically, the lesion showed a disorganized arrangement of spindle cells in a collagenous background and prominent vascular channels of varying size. Tumor cells showed immunohistochemical reactivity for vimentin only. Cytokeratins and CD34 were negative. This report further extends the anatomic range of solitary fibrous tumor, a neoplasm that must be included in the differential diagnosis of well-defined abdominal masses. The behavior of this mesenteric solitary fibrous tumor has been benign.