Pleomorphic sarcoma, also known as Undifferentiated Pleomorphic Sarcoma (UPS), is a rare and aggressive cancer. It originates in the body’s soft tissues, including muscles, fat, and connective tissues that support organs and other body parts. It is categorized as a high-grade sarcoma, indicating its potential for rapid growth and spread.
What is Pleomorphic Sarcoma?
Undifferentiated Pleomorphic Sarcoma (UPS), previously known as malignant fibrous histiocytoma (MFH), is a high-grade soft tissue sarcoma. It accounts for approximately 5% to 10% of all soft tissue sarcomas in adults. This cancer develops from primitive mesenchymal cells, which lack specific differentiation, meaning they haven’t developed into specialized cell types.
UPS tumors are characterized by their “pleomorphic” nature, meaning the cells exhibit varied sizes and shapes when viewed under a microscope. They also show disorganized growth, referred to as “undifferentiated.” While UPS can occur anywhere in the body, it most frequently arises in the deep soft tissues of the extremities, particularly the thigh, as well as the trunk and the retroperitoneum (the area behind the abdominal organs).
These tumors are aggressive, growing rapidly and having a high likelihood of local recurrence. They also have a significant propensity to spread to distant parts of the body, with the lungs being the most common site for metastasis. UPS is more commonly observed in older adults, typically between 50 and 70 years of age, and affects males slightly more often than females.
Recognizing and Diagnosing Pleomorphic Sarcoma
Recognizing pleomorphic sarcoma often begins with a new or growing lump in the soft tissues. This lump may or may not be painful, and its symptoms can vary depending on its size and location. For instance, a tumor pressing on nerves might cause numbness or tingling, while those in an arm or leg could lead to swelling in the affected limb. If the tumor is located in the abdomen, symptoms like discomfort, constipation, or unintended weight loss may occur.
Diagnosis of UPS involves a thorough physical examination, where a doctor assesses the lump’s size, location, and consistency. Various imaging techniques are then employed to visualize the tumor and determine its extent. Magnetic Resonance Imaging (MRI) is often used for tumors in the arms and legs, while Computed Tomography (CT) scans are common for abdominal tumors. Positron Emission Tomography (PET) scans may also be utilized, especially if multifocal disease is suspected or to monitor treatment response.
A definitive diagnosis relies on a biopsy, where a tissue sample is taken from the tumor. This can be done via a needle through the skin or during a surgical procedure. The biopsy sample is then examined by a specialized pathologist under a microscope to identify the characteristic pleomorphic cells and rule out other types of sarcomas through immunohistochemical staining and molecular studies. This detailed pathological examination confirms the diagnosis and determines the tumor’s grade.
Treatment Options for Pleomorphic Sarcoma
Treatment for pleomorphic sarcoma is multidisciplinary, involving approaches tailored to the tumor’s size, location, and spread. Surgical removal is the primary treatment for localized disease. Surgeons aim to remove the entire tumor with a margin of healthy surrounding tissue to minimize remaining cancer cells and reduce local recurrence. For tumors in the arms or legs, limb-sparing surgery is preferred to preserve function, though amputation may be necessary in rare circumstances.
Radiation therapy often complements surgery, administered either before (neoadjuvant) or after (adjuvant) the operation. Pre-operative radiation can shrink larger tumors, making them easier to remove. Post-operative radiation helps eliminate any remaining microscopic cancer cells, reducing the likelihood of local recurrence. This therapy uses high-energy beams to target and destroy cancer cells.
Chemotherapy is another systemic treatment option, usually reserved for larger tumors, metastatic disease, or cases with a high risk of recurrence. It can be given before surgery to reduce tumor size or after surgery to target any remaining cancer cells throughout the body. Emerging treatments include targeted therapies, which focus on specific abnormalities within cancer cells, and immunotherapy, which harnesses the body’s immune system to fight cancer. Clinical trials offer access to these newer, experimental treatments and are often considered for patients with advanced or recurrent disease.
Living With Pleomorphic Sarcoma
After treatment for pleomorphic sarcoma, ongoing follow-up care monitors for any signs of recurrence. This involves regular imaging scans, such as chest X-rays or CT scans, given the high propensity for lung metastasis. Physical examinations and check-ups also assess overall health and detect new symptoms.
The prognosis for individuals with UPS varies, influenced by factors including the tumor’s size, depth, histologic grade, and location. Tumors that are larger, deeper, or located in certain areas like the retroperitoneum may carry a different prognosis compared to smaller, superficial tumors. For instance, a five-year overall survival rate for high-grade UPS is approximately 60%, with a 10-year survival rate of about 48%.
Supportive care and rehabilitation are important aspects of living with UPS, addressing potential long-term effects of treatment like pain, swelling, or reduced mobility. This comprehensive approach helps manage symptoms, improve physical function, and maintain quality of life for patients and their families throughout their recovery and beyond. Psychosocial support can also aid in coping with the emotional challenges of a cancer diagnosis.