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Dedifferentiated liposarcoma

Summary

Dedifferentiated liposarcoma Is a highly malignant soft tissue tumor of adults that occurs most commonly in the retroperitoneal, extremities, and trunk. Some evolved from benign lipomas, but most do not.

This is a tumor of older adults. The tumor can occur from age 20 to age 95, but the peak age of incidents is 62 years.
This tumor presents with an enlarging mass, which may or may not be painful.
Dedifferentiated liposarcoma has no diagnostic features on x-ray.
Wide surgical excision is the most effective treatment. The role of chemotherapy and radiation is controversial.
Complete Information on this Tumor
Introduction and Definition: 

Dedifferentiated liposarcoma is an aggressive soft tissue sarcoma with a relatively poor prognosis. Most patients have no pre-existing lipoma.

Incidence and Demographics: 
This tumor generally presents in older adults, in the retroperitoneum (posterior to the abdominal cavity), extremities, and trunk. Any adult from age 20 to age 100 and be affected. The most common age at diagnosis is around 60.
Symptoms and Presentation: 

Patients present with an enlarging mass. It may be soft and fleshy and relatively painless. Some cases can become very large and remain painless.

X-Ray Appearance and Advanced Imaging Findings: 
On plain radiographs, some tumors will have low density similar to fat, but generally, plain x-rays do not contain any diagnostic information about this tumor.
Differential Diagnosis: 
High-grade sarcoma, (pleomorphicsarcoma / malignant fibrous hysticytoma, other high-grade soft tissue sarcoma.
Preferred Biopsy Technique for this Tumor: 
open , with careful sampling of heterogeneous areas
Histopathology findings: 
The tumor is characterized by different areas of better differentiated lipomatous cells, as well as well-differentiated liposarcoma, high-grade areas resembling fibrosarcoma,myxo sarcoma, even osteosarcoma.
Treatment Options for this Tumor: 
Surgery is the most effective treatment. The role of chemotherapy and radiation is not yet well defined. Generally, patients with high-grade sarcomas with poor prognosis are given chemotherapy if they are medically able to tolerate chemotherapy, and radiation if complete surgical removal of the lesion is not possible. Treatment is individualized and varies significantly between treatment centers. Some sarcoma centers aggregate sarcoma patients into general soft tissue sarcoma protocols that usually include chemotherapy or chemoradiotherapy, but a definite survival benefit for these ultra-expensive, potentially debilitating, and occasionally risky treatments has not been demonstrated for most soft tissue sarcoma.
Preferred Margin for this Tumor: 
wide
Outcomes of Treatment and Prognosis: 
If complete surgical removal is impossible, prognosis is adversely affected. Reports of local recurrence rates as high as 40 to 50% have been published. A distant metastatic rate of approximately 15% has been reported.
Special and Unusual Features: 
Chromosomal translocation in the 12q(13-15) is associated with this sarcoma. In another sarcoma, myxoid liposarcomas, the chromosomal abnormality is characterized primarily by a t(12;16)(q13;p11) .
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