Learning objectives
To describe the radiologic spectrum of musculoskeletal lipomatous tumors,
with emphasis on the manifestations of the benign ones that may cause confusion with liposarcoma.
Background
Lipomatous tumors are the most frequently encountered masses in clinics and are also among the largest group of primary soft tissue tumors.
According to the World Health Organization (WHO) Classification system for soft tissue tumors,
benign adipocytic tumors include lipoma,
lipomatosis,
fibrolipomatous hamartoma of the nerve,
lipoblastoma/lipoblastomatosis,angiolipoma,
myolipoma of soft tissue,
chondroid lipoma,
extra-renal angiomyolipoma,
extra-adrenal myelolipoma,
spindle cell / pleomorphic lipoma and hibernoma.
The majority of these tumors occur in adults,
with the exception of lipoblastoma/lipoblastomatosis.
The diagnosis of typical lipoma is usually straightforward...
Findings and procedure details
We retrospectively reviewed the clinical,
radiological and pathological records of all patients treated at our institution (a tertiary referral hospital) for soft tissue lipomatous benign andintermediate,
low-grade,
locally agressive tumors (ALT/WDL).
Pathological diagnoses included lipoma,
fibrolipomatous hamartoma of the nerve,
lipoblastoma/lipoblastomatosis,
angiolipoma,
myolipoma,
chondroid lipoma,
pleomorphic/spindle cell lipoma,
hibernoma and ALT/WDL.
All patients had CT and/or MRI prior to biopsy and surgery.
The MRI protocol included T1-weighted,
T2-weighted,
fat-suppressed/fluid-sensitive sequences and T1-weighted images after injection of contrast agent (Gadolinium) with and without fat suppression.
Conclusion
A multidisciplinary approach involving oncologists,
surgeons,
pathologists,
radiotherapists and radiologist is needed for the management of these tumors.
Distinction by the musculoskeletal radiologist between benign adipose lesions andwell-differentiated liposarcoma/atypical lipomalypoma is essential as there are significant differences in their treatment and prognosis.
The radiologist reporting soft tissue masses should be aware of the differential characteristics of this heterogeneous group of soft tissue tumors and the frequent overlapping of the imaging features on MRI and CT of benign,
malign and locally agressive fat containing masses.
This...
References
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Leon Lenchik,
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Barry Glenn Hansford,
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(2015) From Tumor to Trauma: Etiologically Deconstructing a Unique Differential Diagnosis of Musculoskeletal Entities With High Signal Intensity on T1-Weighted MRI.
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