Imaging of Musculoskeletal Liposarcoma with Radiologic-Pathologic Correlation

Abstract

Liposarcoma is the second most common type of soft-tissue sarcoma, accounting for 10%-35% of these lesions. The World Health Organization has categorized soft-tissue liposarcomas into five distinct histologic subtypes: well differentiated, dedifferentiated, myxoid, pleomorphic, and mixed type. Well-differentiated liposarcomas frequently demonstrate a diagnostic appearance on computed tomographic (CT) or magnetic resonance (MR) images, with a largely lipomatous mass (>75% of the lesion) and nonlipomatous components in thick septa or focal nodules. The CT or MR imaging finding of a nodular dominant focus (>1 cm in size) of nonlipomatous tissue in a well-differentiated liposarcoma suggests dedifferentiated liposarcoma, and biopsy should be directed at the nonadipose component. The high water content of myxoid liposarcoma seen at pathologic analysis and constituting the majority of the lesion is reflected at sonography, CT, and MR imaging. However, the detection of a small amount of adipose tissue in the septa or as small nodular foci superimposed on the background of myxoid tissue allows prospective diagnosis in 78%-95% of myxoid liposarcomas. Pleomorphic liposarcomas are high-grade sarcomatous lesions and typically appear as heterogeneous soft-tissue masses, although small amounts of fat are seen on MR images in 62%-75% of cases, findings that suggest the diagnosis. Mixed-type liposarcomas have features representing a combination of the other subtypes. Primary liposarcoma of bone is exceedingly rare and usually demonstrates aggressive nonspecific features, although fat may be seen. Understanding and recognition of the spectrum of appearances of the various types of musculoskeletal liposarcoma, which reflect their underlying pathologic characteristics, improves radiologic assessment and is vital for optimal patient management.

Paravertebral High Cervical Chordoma

“…A B C D lar scalloping of the vertebral body [19][20][21] . However, the location of the paravertebral tumor mass lateral and anterior to the vertebral body was against a tumor of nerve root origin, which does not show this pattern of growth.…”

Primary Paraspinal Malignant Peripheral Nerve Sheath Tumor

“…By contrast, MPNSTs classically lack the target sign. Findings on MRI that are suggestive of malignancy include : increase in the size of previously stable neurofibromas, large size, inhomogeneity, ill-defined margins, invasion of fat planes, and perilesional edema 9,12,14,15) . MRI findings of our case, in which the tumor was hyperintense on T1, T2WI and well enhanced, suggested MPNST.…”

Weichteilsarkome: Wie lassen sich posttherapeutische Veränderungen von Rezidiven unterscheiden?

“…Essenziell ist die komplette Resektion des biphasischen Tumors, also auch des (für den Chirurgen vom normalen Fettgewebe nicht unterscheidbaren und radiologisch oft nur anhand des Volumens und der Lokalisation des Fettgewebes im Vergleich zur Gegenseite suspizierten) hochdifferenzierten Anteils, der in 15 % ebenfalls dedifferenzieren kann. Die Resektion abdomineller Organe, etwa der Niere, wird dafür zumeist in Kauf genommen [54,71,83].…”