J Korean Radiol Soc.  1997 Dec;37(6):1121-1126.

Musculoskeletal Adipose tumors of the extremities: Benign vs Malignancy in MR Imaging

• Kim YH
• Kang HS
• Kim YJ
• Ahn JM
• Kim SM
• Shin MJ

Abstract

PURPOSE
The purpose of this study was to evaluate the MR findings of benign and malignant musculoskeletal adipose tumors and to determine the points of difference between these two types.
MATERIALS AND METHODS
This study involved 41 histopathologically proven cases; 26 were benign lipoma and 15 were liposarcoma. T1- and T2-weighted images were obtained in all cases and enhancement study was performed in 15 case of benign lipoma and14 of liposarcoma. To determine MR findings and possible differences between the two groups, we retrospectively analyzed size, location, margin, degree of signal intensity, homogeneity, enhancement pattern and internal septa, as seen on MR images.
RESULTS
On both T1- and T2-weighted images, all lipomas showed a signal intensity similar to that of subcutaneous fat. Twenty-one lipomas had thin and regular internal septa and three showed focal enhancement. On T1-weighted images, 13 of 15 liposarcomas showed linear strands or patchy or diffuse areas with high signal intensity, representing a fatty component. Ten liposarcomas showed inhomogeneous signal intensity and the other five, homogeneous intensity. Irregular and thick septa were seen in nine liposarcomas, and in 12 cases, nodular diffuse enhancement was documented.
CONCLUSION
Homogeneity of signal intensity, enhancing pattern and internal septa might be useful MR findings for the differential diagnosis of benign lipoma and liposarcoma.

Keyword

Lipoma and lipomatosis; Magnetic resonance(MR), tissue characterization; Soft tissues, neoplasms; Soft tissues, MR

MeSH Terms

Diagnosis, Differential
Extremities*
Lipoma
Liposarcoma
Magnetic Resonance Imaging*
Retrospective Studies
Subcutaneous Fat