Septum-like structures in lipoma and liposarcoma: MR imaging and pathologic correlation.
OBJECTIVE
To investigate the septum-like structures in predominantly lipomatous tumors, by correlating fat-suppressed MR images with histopathologic findings.


METHODS
The MR findings of three cases of well-differentiated liposarcoma (atypical lipoma), one case of lipoma-like component of dedifferentiated liposarcoma, and nine cases of lipoma were analyzed. T1-, T2-, and fat-suppressed T1-weighted images after Gd-DTPA administration were obtained. Surgical specimens from five patients (four with liposarcoma and one with lipoma) were also scanned with a MR unit, and compared with the pathologic findings.


CONCLUSIONS
Enhancement features of lipoma and liposarcoma were well visualized on fat-suppressed T1-weighted images after Gd-DTPA administration. The septum-like structures of liposarcoma are thick and enhanced considerably, while septa of lipoma are thin and enhanced only slightly. Pathologically, the septum-like structures of liposarcoma contained muscle fibers and the septa of lipoma represented fibrous capsule. Identification of well-enhanced septa in a predominantly lipomatous tumor helps to differentiate malignant tumors from lipomas. As the septum-like structures of liposarcoma contain a skeletal muscle component the tumor might need more extensive surgical procedures including resection of adjacent muscles.
Hosono
M
M
Department of Nuclear Medicine, Faculty of Medicine, Kyoto University, Sakyo-ku, Japan.
Kobayashi
H
H
Fujimoto
R
R
Kotoura
Y
Y
Tsuboyama
T
T
Matsusue
Y
Y
Nakamura
T
T
Itoh
T
T
Konishi
J
J
D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D005260:Female; D005682:Gadolinium; D019786:Gadolinium DTPA; D006801:Humans; D008067:Lipoma / Q000175:diagnosis / Q000473:pathology*; D008080:Liposarcoma / Q000175:diagnosis / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009135:Muscular Diseases / Q000175:diagnosis / Q000473:pathology; D009942:Organometallic Compounds; D004369:Pentetic Acid / Q000031:analogs & derivatives
D003287:Contrast Media; D009942:Organometallic Compounds; D004369:Pentetic Acid; D005682:Gadolinium; D019786:Gadolinium DTPA