Fat-forming solitary fibrous tumor of the orbit with typical imaging findings

Purpose: We describe a case of fat-forming solitary fibrous tumor (SFT) of the orbit with typical findings on imaging that may improve the awareness of orbital fat-forming SFT. Observations: An 88-year-old female presented with exophthalmos and pain in her right eye. Preoperative imaging showed an oval, well-defined mass with soft-tissue density, interspersed with a well-circumscribed lesion. The lesion showed low-density in computed tomography (CT) scans, hyperintense in T1/T2 weighted images of magnetic resonance imaging (MRI) scans and hypointense in fat-suppressed images of MRI scans. The tumor was removed en bloc and diagnosed as low-grade malignant fat-forming SFT by pathological examination. There was no evidence of recurrence 9-month postoperatively. Conclusions: The imaging feature of orbital fat-forming SFT is a well-defined solid tumor interspersed with adipose tissue. Such findings are vital for the preoperative diagnosis and the choice of the treatment.