What is the primary treatment for myxoid liposarcoma?

Primary Treatment for Myxoid Liposarcoma

The primary treatment for myxoid liposarcoma is wide surgical excision with negative margins (R0), which should be performed by a surgeon specifically trained in sarcoma management. 1

Diagnosis and Staging

• Preoperative diagnosis should be established through core needle biopsy under imaging guidance, with the biopsy tract planned so it can be removed during definitive surgery 1
• MRI is the preferred imaging modality for extremity and trunk myxoid liposarcoma, while CT is recommended for other anatomical sites 1
• Chest CT scan is mandatory for staging to detect pulmonary metastases 1
• Abdominal and pelvic CT scan is specifically recommended for myxoid liposarcoma due to its propensity for extrapulmonary metastases 1
• Spine and pelvic MRI is preferred for myxoid liposarcoma due to its tendency to metastasize to these areas 1
• All diagnostic and treatment decisions should be discussed in a multidisciplinary tumor board 1

Surgical Management

• Wide excision with negative margins (R0) is the standard surgical approach, removing the tumor with a rim of normal tissue around it 1
• The surgery must be performed by a surgeon specifically trained in sarcoma treatment 1
• For extremity myxoid liposarcoma, limb-sparing procedures should be attempted whenever possible 1
• Amputation may be considered in rare cases where adequate margins cannot be achieved with limb-sparing surgery 1
• Plastic surgical reconstruction may be necessary for skin and/or soft tissue defects following wide excision 1

Adjuvant Therapy

• Radiation therapy is standard treatment following wide excision for high-grade, deep lesions >5 cm 1
• Radiation therapy should be administered at a dose of 50-60 Gy with fractions of 1.8-2 Gy, with possible boosts up to 66 Gy 1
• Preoperative radiotherapy may be considered for myxoid liposarcoma as it is particularly radiosensitive and may result in tumor downsizing to facilitate easier resection 1, 2
• The histological response rate to preoperative radiation therapy in myxoid liposarcoma is approximately 77.6% 2
• Chemotherapy may be considered in selected cases, particularly for high-risk patients, though its benefit remains to be definitively established 3, 2

Special Considerations for Myxoid Liposarcoma

• Myxoid liposarcoma has a unique metastatic pattern with a higher propensity for extrapulmonary metastases, particularly to bone (especially spine) and soft tissues 3, 4
• When assessing treatment response in myxoid liposarcoma, the percentage of hypercellular/round cell component and adipocytic maturation should be noted 1
• Tumor size >10 cm and round cell component >5% correlate with increased risk for metastasis and death 3

Follow-up

• Regular surveillance is essential due to the risk of local recurrence and distant metastases 5
• Particular attention should be paid to extrapulmonary sites of metastasis during follow-up imaging 3, 4

Pitfalls and Caveats

• Inadequate surgical margins significantly increase the risk of local recurrence; re-excision should be considered if initial margins are positive 1
• Failure to perform appropriate staging imaging (particularly spine/pelvic MRI) may miss extrapulmonary metastases that are common in myxoid liposarcoma 1, 3
• Misdiagnosis can occur due to the myxoid appearance; central pathological review by an expert sarcoma pathologist is strongly recommended 1
• Patients who undergo inadvertent surgery without a preoperative diagnosis of sarcoma should be fully staged and considered for re-excision of the surgical bed 1