Radiological imaging features and clinicopathological correlation of hemosiderotic fibrolipomatous tumor: experience in a single tertiary cancer center.

OBJECTIVE

To determine the imaging features of hemosiderotic fibrolipomatous tumor (HFLT), which has a propensity towards local recurrence and the potential to transform into myxoinflammatory fibroblastic sarcoma (MIFS).

MATERIALS AND METHODS

The study included 8 patients with a diagnosis of HFLT and imaging at a tertiary cancer center. Imaging studies included radiographs (n = 2), ultrasound (n =  3), and MRI (n = 16). Imaging features were evaluated including location, calcification, sonographic echogenicity, vascular flow, size, border, signal characteristics, contrast enhancement, and blooming on MRI.

RESULTS

The HFLT was located in the ankle/foot in 4 out of 8 and was subcutaneous in 8 out of 8, ranging in size from 2 to 18 cm. Histology at initial diagnosis was HFLT in 5 out of 8 and HFLT with MIFS in 3 out of 8. None was calcified on radiography. On ultrasound 2 out of 3 were heterogeneously echogenic with ≥10 foci of vascular flow. Two out of 8 patients had MRI only at local recurrence. The tumor border was infiltrative in 4 out of 6 at initial diagnosis and in 2 patients with MRI at recurrence only. Fat and septae were present in 7 out of 8 at initial diagnosis and at recurrence. Signal intensity was iso-/hypointense to muscle on T1-weighted sequences in more than two thirds of the tumor in 4 out of 7 and hyperintense to muscle in at least one third of the tumor on fluid-sensitive sequences in 6 out of 8. Contrast enhancement was heterogeneous in 7 out of 7; blooming in two thirds of the tumor on gradient-echo sequence MRI indicated hemorrhage.

CONCLUSION

The HFLT commonly presents as a mass with an infiltrative border, interspersed fat and septations at initial diagnosis and local recurrence on MRI regardless of histology of HFLT alone or with MIFS. Hemosiderin deposits may be detected as blooming on gradient-echo sequences.