Liposarcoma is a cancer that arises in fat cells in deep soft tissue, such as that inside the thigh or in the retroperitoneum.
Liposarcoma is a rare type of cancer that bears a resemblance to fat cells when examined under a microscope.
They are typically large bulky tumors, and tend to have multiple smaller satellites that extend beyond the main confines of the tumor.
Liposarcomas, like all sarcomas, are rare.
Signs and symptoms
Patients usually note a deep seated mass in their soft tissue. Only when the tumor is very large do symptoms of pain or functional disturbances occur.
Retroperitoneal tumors may present themselves with signs of weight loss and emaciation and abdominal pain.
These tumors may also compress the kidney or ureter leading to kidney failure.
The diagnosis is established by histologic examination of the tissue, i.e., biopsy or excision.
Lipoblasts are often present; these are cells with an abundant clear multi-vacuolated cytoplasm and an eccentric darkly staining nucleus that is indented by the vacuoles.
Several subtypes of liposarcoma exist:
- Well-differentiated liposarcoma, synonymous with atypical lipomatous tumor—the former term is used almost exclusively for lesions in the retroperitoneum, while the latter is used for lesions arising elsewhere
- Dedifferentiated liposarcoma—well-differentiated (high-grade) liposarcoma adjacent to a more poorly differentiated tumor
- Myxoid/round cell liposarcoma.
- Pleomorphic liposarcoma.
The prognosis varies depending on the site of origin, the type of cancer cell, the tumor size, the depth, and proximity to lymph nodes.
Well-differentiated liposarcomas treated with surgery, intra-operative distilled water lavage and radiation have a low recurrence rate (about 10%) and rarely metastasize.
Five-year survival rates vary from 100% to 56% based on histological subtype.