OBJECTIVETo investigate the correlation between the pathological and image features of different subtypes of retroperitoneal liposarcoma.

METHODSPathological and image characteristics of 21 retroperitoneal liposarcomas were retrospectively analyzed comparing their different histopathological subtypes.

RESULTSThis series consisted of 11 well-differentiated, 4 myxoid, 3 round-cell, 2 pleomorphic and 1 dedifferentiated liposarcoma. Well-differentiated liposarcomas were predominantly composed of lipoma-like and sclerosing components. On CT and MRI image, the attenuation and signal intensity of lipoma-like components resembled those of fat, whereas the signal intensity of sclerosing components was similar to those of muscle. Unenhanced CT image of the myxoid subtype showed density resembling that of water. On contrast-enhanced CT image, it showed gradual reticular or sheet-like enhancement. The CT and MRI image appearance of the round cell and pleomorphic subtypes resembled those of nonfatty soft tissue masses with foci of necrosis. The dedifferentiated liposarcoma showed the image feature of a well-differentiated component clearing enhanced soft tissue mass.

CONCLUSIONDifferent subtypes of retroperitoneal liposarcoma show different CT and MRI features relating to their major histologic components. A good understanding of the relation between their radiological and pathological features is helpful to arrive at a correct diagnosis for retroperitoneal liposarcoma.