Liposarcoma of soft tissue: MRI findings with pathologic correlation.

OBJECTIVE

To evaluate the MRI findings of liposarcomas of different histologic types and correlate these with the histopathologic features.

DESIGN

The MR images of seven liposarcomas were reviewed retrospectively to assess the tumor size, location, margination, signal characteristics and enhancement patterns in different histologic types.

PATIENTS

Seven liposarcomas comprising three well-differentiated, two myxoid and two pleomorphic types were evaluated.

RESULTS AND CONCLUSION

All tumors showed well-defined and mostly lobulated margins. The well-differentiated liposarcomas were composed mainly of fat with septations or nodules, were hyperintense on T2-weighted images, and demonstrated faint enhancement or no enhancement following intravenous contrast. Myxoid liposarcomas were homogeneous or mildly heterogeneous and a pseudocapsule was present in one case. Pleomorphic types showed a markedly heterogeneous internal structure. Both myxoid and pleomorphic lesions-showed moderate or marked heterogeneous enhancement after contrast administration. Well-differentiated liposarcomas may be differentiated from other types of the tumor by their largely lipomatous appearance. The malignancy grade increases in parallel with tumor heterogeneity and contrast enhancement.