Dedifferentiated liposarcoma of retroperitoneum: spectrum of imaging findings in 15 patients.
BACKGROUND
Dedifferentiated liposarcoma is a high-grade nonlipogenic sarcoma that arises in the background of a preexisting well-differentiated liposarcoma. The purpose of this work is to evaluate the spectrum of radiologic appearance of retroperitoneal dedifferentiated liposarcoma with clinicopathologic features.


METHODS
Radiologic images and clinical histories of 15 patients with histologically verified retroperitoneal dedifferentiated liposarcoma were retrospectively studied. Patients included 11 men and 4 women, with mean age of 55.8 years (range, 36-74 years), and they underwent computed tomography (CT) (n=15) and magnetic resonance imaging (MRI) (n=5).


RESULTS
The mean size of the tumor was 22.6 cm with a range of 9.5-38 cm. Both CT and MRI showed well-circumscribed, large round, or lobulated retroperitoneal mass. The appearance of the tumor was classified as follows: Category I, nonfatty component within predominant fatty mass (n=5); Category II, focal fatty component within large nonfatty mass (n=6); Category III, well-defined fatty mass and well-defined nonfatty mass (n=1); Category IV, two masses with predominantly nonfatty component (n=3).


CONCLUSIONS
Retroperitoneal dedifferentiated liposarcomas present various spectra of imaging findings. While Categories I and III may suggest dedifferentiated liposarcoma, Categories II and IV may appear as other types of liposarcoma or other malignant retroperitoneal tumor.
Hong
Sun Hwa
SH
Department of Radiology, Korea University College of Medicine, Seoul, South Korea.
Kim
Kyeong Ah
KA
Woo
Ok Hee
OH
Park
Cheol Min
CM
Kim
Chul Hwan
CH
Kim
Myeong-Jin
MJ
Chung
Jae-Joon
JJ
Han
Joon Koo
JK
Rha
Sung Eun
SE
D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008080:Liposarcoma / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012186:Retroperitoneal Neoplasms / Q000175:diagnosis*; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*