Computed tomography of lipomatous and myxoid tumors

Thirty-two lipomatous and myxoid tumors were examined by computed tomography (CT). An attempt was made to correlate the radiographic appearance of the tumor to different histologic types of these tumors. It was found that a well delineated lipomatous lesion with uniform radiographic density, an attenuation value below -73 Hounsfield units (HU) and absence of contrast enhancement can be considered strongly suggestive of a benign lipoma. Atypical lipomas, myxoma and well differentiated liposarcomas have good delineation against the surrounding tissue with no peripheral hypervascularity in the majority of cases. The attenuation values varied between -83 and +38 HU. Liposarcomas of myxoid type, mixed myxoid and round-cell type, round-cell type, and pleomorphic type were all poorly delineated with attenuation values between +12 and +38 HU and with varying contrast enhancement. Thus CT can be considered to play an important role in the preoperative evaluation of lipomatous and myxoid tumors of the soft tissues. Besides valuable topographic information CT helps, to some extent, to differentiate between various types of lipomatous tumors.