[Magnetic resonance tomography of liposarcoma].

PURPOSE

Liposarcoma is the most common soft tissue sarcoma in adults. The purpose of the study was to correlate MR imaging features with the four ICD subclasses.

METHODS

28 patients with liposarcoma were examined preoperatively on a 1.0 T MRI system, using spin echo sequences, gradient echo imaging and STIR sequences. In all patients, classification of the liposarcomas was made by histologic diagnosis (ICD-10-M-classification).

RESULTS

Well differentiated liposarcomas (9 patients) showed a number of MRI features consistent with lipoma (well defined mass high signal intensity (SI) on T1 images, low signal on T2 images, no or only little signal increase of tumour tissue after contrast material application, no necrosis). Not well differentiated liposarcomas (myxoid 14 patients, pleomorphic three patients, round cell two patients) revealed the largest part of the mass to be of low SI on T1-weighted images. Only scattered fatty islands and septa (9 patients with myxoid liposarcoma had more SI in T1-weighted images. T2-weighted image showed most of the mass to be of intermediate to high SI are the fatty island of relatively low SI. The probability of tumor necrosis increased with lower tumour grading.

CONCLUSION

MRI seems to be valuable to identify well differentiated liposarcomas.