Keywords:
Oncology, Musculoskeletal system, Musculoskeletal soft tissue, MR, CT-High Resolution, Comparative studies, Education, Perception image, Cancer, Education and training, Neoplasia
Authors:
M. E. Scherer1, J. Cardenas Marquez2, E. Rossetto1, A. Calderwood1, F. M. Olivera Plata1, P. Schvartzman1, C. R. Deragopyan1; 1CABA, C.A.B.A/AR, 2Buenos Aires/AR
DOI:
10.1594/ecr2018/C-2324
Results
Conventional lipomas may contain a few thin septa.
Nevertheless,
they are homogeneously fatty masses (fig.
1).
Bands of muscle fibers are also acceptable components of intramuscular lipomas.
Thickened or nodular septa (generally > 3 mm),
associated nonadipose masses,
prominent foci of high T2 signal,
and prominent areas of enhancement are all associated with increased risk of well-differentiated liposarcoma (fig.
2).
A well-differentiated liposarcoma produces an image of a predominantly fatty mass with irregularly thickened linear or nodular septa,
which decreases signal intensity on T1-WI and increases signal intensity on T2-WI.
The myxoid,
round and pleomorphic subtypes do not contain substantial amounts of fat.
A dedifferentiated type is best defined as a bimorphic neoplasm in which a borderline or low-grade malignant neoplasm is juxtaposed with a highgrade sarcoma (fig.
3).
The subtypes of liposarcomas with greater nonlipomatous components on imaging studies tend to show less differentiation and are usually more aggressive histologically and clinically.
The features to correlate radiological and microscopic findings are the size (exceeding 30 mm),
presence of thick or nodular septa,
areas with high T2 and low T1 signal intensity,
contrast enhancement,
a partially ill-defined margin,
neurovascular involvement,
calcifications,
hemorrhage and muscular fibers.
The most statistically significant predictor of liposarcoma was thick irregular septa and nonfatty elements.
Lipomas typically have a characteristic MR imaging appearance that is independent of location (image 5).