CT and MR imaging of abdominal liposarcoma.

OBJECTIVE: CT and MR images were reviewed to correlate the histologic subtypes of abdominal liposarcoma with the radiologic findings.

SUBJECTS AND METHODS: Ten patients with liposarcoma who underwent CT or MR imaging before surgery were included in this study. CT and MR imaging findings for these patients were compared retrospectively with histologic findings.

RESULTS: Major histologic subtypes found in our group of patients were five well-differentiated, three myxoid, one pleomorphic, and one round-cell liposarcomas. The well-differentiated subtype consisted of lipoma-like and/or sclerosing components. The predominant attenuation and signal intensity characteristics of the lipoma-like components on CT and MR images resembled those of fat, whereas the predominant attenuation and signal intensity characteristics of the sclerosing components resembled those of muscle. The myxoid subtype showed, on unenhanced images, predominant attenuation and signal intensity characteristics that resembled those of water; on contrast-enhanced images, this subtype showed gradual reticular enhancement. The appearance of the round-cell and pleomorphic subtypes was that of heterogeneous, nonfatty tumors. Their characteristics were indistinguishable from those of other malignant soft-tissue masses.

CONCLUSION: Each histologic subtype of abdominal liposarcoma showed different CT attenuation or MR imaging signal intensity characteristics. A clear understanding of these findings should prove helpful in the diagnosis of liposarcoma.