Foci of signal intensities different from fat in well-differentiated liposarcoma and lipoma: correlation between MR and histological findings.

To investigate the histological features of foci, which showed signal intensities different from fat by magnetic resonance (MR) imagings in well-differentiated lipoma-like liposarcomas and a case of lipoma, a retrospective review of these lipomatous tumors was performed to correlate MR and histological findings. Microscopic findings revealed that these foci were also composed of lipomatous tissue. Well-differentiated liposarcoma and benign lipoma associated with such foci should be differentiated from dedifferentiated liposarcoma based on the histological findings.