|
Year |
2007 |
|---|---|
|
Question Number |
70 |
|
Category |
Orthopaedic Disease |
Question
A 32-year-old woman has a large soft-tissue mass in the proximal thigh and gluteal region. A radiograph and axial and sagittal MRI scans are shown in Figures 21a through 21c. Biopsy specimens are shown in Figures 21d and 21e. What is the most likely diagnosis?
1- Pleomorphic sarcoma
2- Liposarcoma
3- Synovial sarcoma
4- Malignant nerve sheath tumor
5- Aggressive fibromatosis
Figures
Answer (click for answer)
Answer: 2- Liposarcoma
Myxoid liposarcoma is the most common fat sarcoma, accounting for 40-50% of all liposarcomas. The myxoid type is low to intermediate grade and seen in patients in the 4th to 6th decade of life. The clinical presentation is similar to the well-differentiated liposarcoma. Gross examination of a myxoid liposarcoma reveals a lobulated pattern with some areas that appear similar to those of a lipoma but with other myxomatous areas. Microscopic examination shows myxoid tissue with areas of signet ring lipoblasts. It is common to find a delicate pattern of capillaries running through the myxoid areas. MRI frequently demonstrates a heterogeneous high- and low-signal pattern (dark on T1, bright on T2) typical of myxoid liposarcoma, but not present in cases of benign lipoma. Characteristic translocations are also seen in myxoid liposarcoma. The predominant type is t(12;16)(q13;p11); however, t(12;22)(q13;q12) is also described. Although myxoid liposarcoma carries a very good prognosis, the tumor should be removed with wide margins, and adjuvant radiation therapy should be given. Chemotherapy is not indicated.
Reference:
Attachments:
OITE 2007 figure 21d.jpg (image/jpeg)
OITE 2007 figure 21c.jpg (image/jpeg)
OITE 2007 figure 21a.jpg (image/jpeg)
OITE 2007 figure 21e.jpg (image/jpeg)
OITE 2007 figure 21b.jpg (image/jpeg)
