Liposarcoma overview
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Liposarcoma Microchapters |
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Diagnosis |
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Liposarcoma overview On the Web |
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American Roentgen Ray Society Images of Liposarcoma overview |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Alejandro Lemor, M.D. [2]; Ammu Susheela, M.D. [3]
Overview
Liposarcoma is a malignant tumor that arises in fat cells in deep soft tissue, such as that inside the thigh or in the retroperitoneum.
They are typically large bulky tumors which tend to have multiple smaller satellites extending beyond the main confines of the tumor.
Historical Perspective
Since 1857, liposarcoma has been reported in many occasions and describing the most common locations and subtypes. Attempts to classify this disease started in 1954, and the most recent classification by the WHO is in 2013.
Classification
Liposarcoma, a type of soft tissue sarcoma may be classified into: well-differentiated, dedifferentiated, myxoid, round cell, or pleiomorphic liposarcoma.
Pathophysiology
Liposarcoma usually presents as a painless tumor in any part of the body. It is the second most common type of soft tissue sarcoma.It is usually 5 types and have got poor prognosis.
Causes
The etiology of liposarcoma is unknown. However genetic and enviornmental factors are associated with liposarcoma.
Differentiating Liposarcoma from other Diseases
Liposarcoma must be differentiated from other diseases that cause a painless, growing mass such as spindle cell lipoma, neurofibroma, dermatofibrosarcoma protuberans, and malignant peripheral nerve sheath tumor.
Epidemiology and Demographics
Liposarcoma are the second most common type of soft tissue sarcoma in adults. The annual incidence is 0.25 cases per 100,000 population. Men are more affected than women and it is mostly seen in elderly and has got poor prognosis.
Risk Factors
Risk factors of liposarcoma includes chemical carcinogen, genetic disorders, radiation and immunodeficiency. These increases the risk of liposarcoma in general population.
Natural History, Complications and Prognosis
Liposarcoma may have different clinical presentations depending on the location of the mass, being the lower extremities the most common area involved. Metastasis is the most important aspect to assess in the prognosis of the disease, but the mass may compress adjacent structures causing different clinical manifestations. The prognosis will depend on the histopathological subtype, being the well differentiated liposarcoma the subtype with the best prognosis, and the pleomorphic liposarcoma with the worst prognosis.
Diagnosis
Staging
The staging for liposarcoma is based on the TNM classification, depending on the primary tumor, lymph node involvement, metastasis and the histological grade of the tumor.
History and Symptoms
Liposarcomas usually present as a growing mass, not associated with pain and commonly located in the lower extremities. Retroperitoneal liposarcomas remain asymptomatic until they affect adjacent structures, causing pain or obstructive symptoms.
Physical Examination
The physical examination findings will depend on the location of the liposarcoma, being the most common location the lower extremities. The main finding is a painless, slow growing, firm mass in one of the lower extremities. Retroperitoneal liposarcomas would have a late presentation and the physical examination findings include abdominal tenderness, abdominal distention and weight loss.
Laboratory Findings
A biopsy of the liposarcoma will give the definitive diagnosis and the histopathological subtype of liposarcoma. Other laboratory finding include anemia, due to GI bleeding, and increased BUN and creatinine in case of obstructive nephropathy.
CT
CT imaging is one of the most important tests for the diagnosis of liposarcoma. CT should assess the size, location and depth of the liposarcoma, as well as the lymph node involvement and distant metastasis. CT findings can be correlated with the histopathological subtype.
MRI
MRI is the imaging test of choice for the diagnosis of liposarcoma and should assess size, location and depth of the mass. MRI findings help to differentiate between the different subtypes of liposarcoma and help to assess distant metastasis.
Other Imaging Findings
Other diagnostic imaging for liposarcoma include a positron emission tomography (PET) scan.[1]
Other Diagnostic Studies
Genetic assessment is one of the other diagnostic test for liposarcoma.
Treatment
Medical Therapy
Treatment of liposarcoma is based on an integrated approach by a multidisciplinary team based on the medical history and physical examination, imaging, biopsy and genetic studies of the tumor. Chemotherapy, chemoradiation, immunotherapy and targeted therapy are the different types of medical therapy for liposarcoma.
Surgery
Surgery is the primary treatment of liposarcoma. It may be integrated with chemotherapy and radiation therapy depending on the site, stage and recurrence of the tumors.
Cost-Effectiveness of Therapy
Future or Investigational Therapies
References