What Is Undifferentiated Pleomorphic Sarcoma?
Undifferentiated pleomorphic sarcoma (UPS) is a type of cancer that generally originates in the soft tissues of the body, such as the muscles, fat, and connective tissue. Earlier, it was referred to as malignant fibrous histiocytoma, but this terminology has been replaced by the more recent term, undifferentiated pleomorphic sarcoma.
It is quoted as undifferentiated because the cancer cells lack the specific cell type characteristics, making it challenging to find the origin of the cancer. This cancer is pleomorphic because these cells can grow in multiple shapes and sizes. When UPS occurs within bone tissue, it is called undifferentiated pleomorphic sarcoma of the Bone. Compared to UPS of soft tissues, UPS of the bone is rare and poses unique challenges in diagnosis and treatment. It occurs commonly in the legs and arms when compared with other parts of the body.
What Is the Cause of Undifferentiated Pleomorphic Sarcoma of the Bone?
The exact cause of undifferentiated pleomorphic sarcoma of bone and soft tissues remains unclear. However, certain risk factors are believed to cause the development of UPS, including:
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Age - UPS of bone is most commonly diagnosed in patients over 50. However, it can affect people of all ages.
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Radiation Exposure - Previous exposure to radiation therapy for other cancers has been associated with an increased risk of UPS.
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Prior Trauma - In rare instances, trauma or injury to bone tissue may also cause UPS in bone.
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Genetic Factors - Some genetic changes or conditions, such as Li-Fraumeni syndrome, have been linked with an increased UPS in bone risk.
What Are the Symptoms of Undifferentiated Pleomorphic Sarcoma of the Bone?
Undifferentiated pleomorphic sarcoma of the bone’s symptoms varies depending on the location and size of the tumor. In general, UPS of the bone shows the following signs:
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The most common symptoms of UPS of the bone are persistent and localized bone pain. Typically, the pain may worsen with physical activity or at night.
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A lump or swelling may develop at the site of the tumor.
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If the tumor is present near a joint, it can limit the range of motion and lead to stiffness in the affected limb.
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UPS of the bone can weaken the affected bone, increasing the fracture risk, even with minor injury.
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If the UPS affects the spinal column or nearby nerves, individuals may experience neurological symptoms, such as numbness, weakness, or tingling.
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Some individuals may experience nonspecific symptoms like unintentional weight loss, fatigue, or night sweats.
How Is Undifferentiated Pleomorphic Sarcoma of the Bone Diagnosed?
UPS of the bone diagnosis is a complex process requiring a multidisciplinary approach.
The following are the steps involved in the diagnostic of UPS of the bone:
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Clinical Evaluation - The first step is a thorough clinical evaluation of the patient's medical history, including presenting symptoms, onset of diseases, history, etc, and a thorough physical examination to identify any physical findings.
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Imaging Studies - Various imaging studies, such as X-rays, CT (computerized tomography) scans, MRI (magnetic resonance imaging) scans, and bone scans, are conducted to check the tumor size, its exact location, and involvement of surrounding structures and identify any metastases.
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Biopsy - A biopsy is a very important element to confirm the diagnosis. A biopsy is a procedure to collect a sample or piece of tissue of cells from the body through a minimally invasive procedure or surgery and send it to the laboratory for checking by a pathologist to determine the type and grade of the tumor.
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Immunohistochemistry - Immunohistochemistry is a procedure that helps identify specific proteins present in the tumor cells. The details about the specific proteins can provide knowledge of the tumor's origin and nature.
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Molecular Testing - In some cases, molecular testing may be required to identify specific genetic mutations that could guide treatment decisions.
What Is the Treatment for Undifferentiated Pleomorphic Sarcoma of the Bone?
Treating UPS of the bone typically involves a multidisciplinary approach, including surgery, chemotherapy, and radiation therapy. The treatment choice also depends on the location of the tumor, the stage of the disease, the patient's overall health, and individual factors.
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Surgery - Surgical resection is the first-line treatment for UPS of the bone. The main aim of the surgery is to remove the tumor completely, including the margin of healthy tissue around it. This is done to minimize the risk of recurrence. In some rare cases, limb-sparing surgery may preserve function and appearance.
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Chemotherapy - In cases of metastasis of the cancer or if there is a high risk of distant spread, systemic chemotherapy is used. Chemotherapy drugs are given through the bloodstream to target cancer cells all over the body.
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Radiation Therapy - Radiation therapy is commonly performed after surgery to kill any remaining cancer cells and also to reduce the risk of local recurrence. If surgery is not feasible in some patients, radiation therapy may be the primary treatment.
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Targeted Therapies - It is an evolving therapy that uses drugs to target specific proteins and genes that help in the survival and growth of cancer cells. Some specific genetic alterations in the UPS of the bone may respond to targeted therapies. These drugs interfere with the molecular pathways driving cancer growth.
What Is the Prognosis of Undifferentiated Pleomorphic Sarcoma of the Bone?
The prognosis for UPS of the bone can vary depending on factors, including the location of the tumor, the stage of the disease, and the patient's overall health. Unfortunately, UPS has a fast-growing nature and also tends to recur even after successful treatment. Survival rates are reported in terms of five-year survival, and the patients who survive beyond this period are less likely to experience a recurrence. Overall, the five-year survival rate for UPS of the bone can vary from 20 % to 60 %, depending on the extent, stage, and location of the disease.
Conclusion
Undifferentiated pleomorphic sarcoma of the bone is an uncommon and fast-growing form of cancer that affects bone tissue. Its diagnosis and treatment are challenging and require a multidisciplinary approach involving oncologists, surgeons, and pathologists. Surgery is the prime treatment option for the aggressive nature of UPS. However, early diagnosis and intervention are critical to improving outcomes.
