Related narratives: Myxoid Liposarcoma, Ischiorectal Myxoid Liposarcoma, Sarcoma of the Thigh
Soft tissue sarcomas most commonly arise in the extremities (40% lower, 20% upper) and usually present as a slowly growing mass before becoming painful. They typically arise in the fifth and sixth decades of life. They invade locally along tissue planes and into adjacent structures. Lymphatic spread is rare except for epitheleoid, rhabdomyosarcoma and clear cell sarcomas. About 1/4 of patients with sarcomas have metastases at presentation, typically to lung. Size and grade correlate with metastases, with lesions larger than 20 cm having an 80% metastatic rate.
Liposarcoma is the second most common soft tissue malignancy after malignant fibrous histiocytoma. There is a spectrum of histological types and grades with differing behaviors. In order of increasing aggressiveness they are well differentiated, myxoid, round cell and pleomorphic lesions. There are often different types mixed in the same tumor.
Diagnosis is best made by core needle or incisional biopsy. The biopsy site is removed with the resection. Treatment for localized liposarcoma is wide (2 cm margins ideally) resection plus radiation. Proximity to a fascial or deep boundary may limit some margins. The 1970's NIH trials showed no advantage of complete compartment resection over wide local excision with radiotherapy and compartment resection is now rarely performed. Indications for amputation include high grade lesions, involvement of major neurovascular structures or multiple compartment involvement.
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