Giant solitary fibrous tumor of the pelvis: A case report and review of literature.

Introduction: Solitary fibrous tumors (SFTs) are rare spindle cells neoplasms most likely arising from mesenchymal cells. Usually they involve the pleura. Even if extra-thoracic SFTs are rare, lately they are diagnosed with increased frequency.

Case Presentation: We describe the case of giant pelvic and retroperitoneal neoplasm, a rare solitary fibrous tumor, in a 51-year-old man that was admitted for abdominal pain.

Discussion: On CT a SFT appears usually as a smooth, lobulated mass with occasional calcifications, but the imaging differential diagnosis with other mesenchymal tumors is very difficult, if not impossible.

Conclusion: The histological and immune-histochemical features of SFTs are helpful for the differential diagnosis. The malignant potential of this cancer is low, but it is very important to perform an optimized surgery and a close follow up in the patient. We believe that this case is particularly interesting and complex because of the difficulty of predicting the future biological behavior.