Solitary fibrous tumor arising from the mesentery of adult patients. Report of two cases and review of the literature.

Solitary fibrous tumors (SFTs) represent an uncommon entity most frequently manifested in the pleura. We describe herein two new cases located in the jejunal and sigmoid mesentery incidentally found in patients aged 61 and 32 years. In a review of the literature, we have compiled 15 mesenteric SFTs including our two cases. The mean age of the patients at presentation was 51.7 years (range, 26-83 years). Most patients were males (males:females 4:1). Although occasionally these tumors were an incidental finding, the majority have been symptomatic. Tumors varied greatly in size (3 to 25 cm), but most of them were large (mean 14.8 cm). Most cases (60%) were located in the small intestine mesentery. The hemangiopericytomatous (cellular) variant was the most common. All patients were treated by surgery and no other therapeutic approaches (chemo-/radiotherapy) were used. Follow-up data were available in 11 cases and ranged from six days to 21 years, with a mean follow-up period of 36.2 months. None recurred or metastasized. Two (13.3%) of the 15 cases showed atypical histological features concordant with histological, but not clinical malignancy. The main differential diagnosis includes gastrointestinal stromal tumor, synovial sarcoma and reactive nodular fibrous pseudotumor of the mesentery. In one third of the cases, tumor excision did not require intestinal resection. To our knowledge, our Case No. 1 is the first reported that has been removed through laparoscopic surgery. Radical surgery remains the treatment of choice. The unpredictable behavior of SFTs requires a careful, close, long-term follow-up.