OBJECTIVE: This study aimed to describe magnetic resonance imaging (MRI) features of extremity liposarcoma (LPS) subtypes, correlating with histopathology and clinical outcomes. METHODS: In this retrospective study, we included 125 patients (80 men, 45 women; mean age, 53 years) with extremity LPS [23 atypical lipomatous tumor (ALT), 9 dedifferentiated (DDLPS), 70 myxoid (MLPS), 23 pleomorphic (PLPS)]. Pretreatment MRI of primary tumors in 56 patients (10 ALT, 4 DDLPS, 28 MLPS, 14 PLPS) was reviewed. RESULTS: All subtypes were predominantly T1 isointense relative to skeletal muscle (DDLPS = 3/4, MLPS = 28/28, PLPS = 13/14) and T2 hyperintense (ALT = 10/10, DDLPS = 3/4, MLPS = 28/28, PLPS = 14/14) except for ALT which were T1 hyperintense (8/10). Within MLPS, high grade was associated with unencapsulated margins (P = 0.05) and solid, nodular enhancement (P < 0.0001). Peritumoral edema (P = 0.03) and T2 heterogeneity (P = 0.05) predicted pulmonary (rather than extrapulmonary) metastases in MLPS. Tumor subtype correlated with mortality (P = 0.04). CONCLUSIONS: The MRI features can help to distinguish between extremity LPS subtypes, and can predict histopathologic grade and metastatic pattern in myxoid LPS.
OBJECTIVE: This study aimed to describe magnetic resonance imaging (MRI) features of extremity liposarcoma (LPS) subtypes, correlating with histopathology and clinical outcomes. METHODS: In this retrospective study, we included 125 patients (80 men, 45 women; mean age, 53 years) with extremity LPS [23 atypical lipomatous tumor (ALT), 9 dedifferentiated (DDLPS), 70 myxoid (MLPS), 23 pleomorphic (PLPS)]. Pretreatment MRI of primary tumors in 56 patients (10 ALT, 4 DDLPS, 28 MLPS, 14 PLPS) was reviewed. RESULTS: All subtypes were predominantly T1 isointense relative to skeletal muscle (DDLPS = 3/4, MLPS = 28/28, PLPS = 13/14) and T2 hyperintense (ALT = 10/10, DDLPS = 3/4, MLPS = 28/28, PLPS = 14/14) except for ALT which were T1 hyperintense (8/10). Within MLPS, high grade was associated with unencapsulated margins (P = 0.05) and solid, nodular enhancement (P < 0.0001). Peritumoral edema (P = 0.03) and T2 heterogeneity (P = 0.05) predicted pulmonary (rather than extrapulmonary) metastases in MLPS. Tumor subtype correlated with mortality (P = 0.04). CONCLUSIONS: The MRI features can help to distinguish between extremity LPS subtypes, and can predict histopathologic grade and metastatic pattern in myxoid LPS.