Is the nonlipomatous component of dedifferentiated liposarcoma always soft tissue on CT? Analysis of CT densities and correlation with rate of growth in 60 patients.

[liposarcoma]

To define the various CT densities of nonlipomatous component of dedifferentiated liposarcoma (DDLPS ) and to determine if the rate of growth varies with density .This study identified 60 patients with DDPLS (38 men , 22 women ; mean age at diagnosis 59 Â years , range , 35 -82 Â years ) who had one or more resections . CT scan immediately before the surgical resection (presurgery ) and up to a maximum of one year before the surgery (baseline ) was reviewed by two radiologists to note the density of the nonlipomatous elements and rate of growth during that period . Clinical and histopathological data were extracted from electronic medical records . Rate of growth of various densities was compared using Kruskal-Wallis test .Three distinct densities of the nonlipomatous component were noted : soft tissue density (SD ), fluid density (FD ), and mixed density (MD ). Of 109 lesions on the presurgery scan (SD Â =Â 78 ; MD Â =Â 22 ; FD Â =Â 9 ), scans at baseline were available for 72 /109 lesions (SD Â =Â 49 ; MD Â =Â 14 ; FD Â =Â 9 ). Median growth rate /month without treatment , with chemotherapy , and with radiotherapy were 40 %, 24 %, and 62 %, respectively , for SD lesions and 28 %, 61 %, and 52 % for MD lesions . For FD lesions , it was 72 % and 35 %, respectively , without treatment and with chemotherapy . There was no statistical difference in the rate of growth of various densities . Density changed over time in 8 /72 (11 %) lesions , including 2 /49 SD lesions (to MD ), 1 /14 MD lesions (to SD ), and 5 /9 FD lesions (to SD ).DDLPS has three distinct CT densities of which soft tissue density is the most common . Despite not being statistically significant , fluid density lesions had rapid growth rate and often converted to soft tissue density in our study .