Liposarcoma: MR Findings in the Histologic Subtypes

ABSTRACT

PURPOSE: To evaluate the MR imaging findings of liposarcomas of different histologic subtypes. MATERIALS AND METHODS: We evaluated MR images of 21 patients (5 men and 16 women, mean age, 55 years) with liposarcoma andcorrelated the findings with the results of histopathology. In the study group seven liposarcomas werewell-differentiated, seven were myxoid, three were mixed, two were pleomorphic, and one was round cell. RESULTS: On T1 -and T2 - weighted images, six of seven well-differentiated liposarcomas showed signal intensity equal tothe fat and hypointense septa, while the other showed low signal intensity on a T1 -weighted image, heterogeneoushigh signal intensity on a T2- weighted image, heterogeneous enhancement after the administration of contrastmedia and was dedifferentiate. Nine masses in seven patients with myxoid liposarcoma showed low signal intensityon T1-weighted images, six of the nine showed lace-like foci of high signal intensity. On T2 -weighted images, allmasses showed homogeneous high signal intensity. After administration of contrast media, five of seven massesshowed heterogeneous enhancement. Two of three mixed form were well-differentiated and myxoid types, and twosubtypes were separable on MR. Pleomorphic, round cell, mixed type myxoid and pleomorphic and unclassified casesshowed low signal intensity on T1-weighted images, heterogeneous high signal intensity on T2-weighted andheterogeneous enhancement. CONCLUSION: Using MR imaging, well-differentiated and myxoid liposcarcomas may bedifferentiated from other types.