Overview
Undifferentiated Pleomorphic Sarcoma (UPS) is a rare and aggressive type of soft tissue cancer that typically originates in the muscles, ligaments, fat, or fibrous tissues of the body. Once known as malignant fibrous histiocytoma, UPS is characterized by its highly variable cell appearance and tendency to grow rapidly. Although it can affect anyone, it most often occurs in adults and requires timely diagnosis and a multidisciplinary treatment approach.
What is Undifferentiated Pleomorphic Sarcoma
Undifferentiated Pleomorphic Sarcoma (UPS) is a high-grade soft tissue sarcoma with no identifiable cell of origin, meaning the cancerous cells are so irregular that they don’t resemble any normal tissue type under a microscope. This tumor often appears in the extremities—especially the thighs—but can also develop in the trunk, retroperitoneum, or head and neck region. UPS is locally aggressive and has a risk of metastasis, most commonly to the lungs. It typically affects adults over the age of 50.
Symptoms
- A painless, enlarging mass or lump (often in the limbs)
- Swelling or firmness in the affected area
- Limited range of motion if near joints
- Pain or tenderness as the tumor grows and presses on nearby structures
- Fatigue or unintentional weight loss (in advanced cases)
- Symptoms related to metastasis (e.g., shortness of breath if spread to lungs)
Causes
The exact cause of Undifferentiated Pleomorphic Sarcoma is unknown, but several factors may increase the risk of developing this malignancy:
- Genetic mutations in the tumor cells
- Previous radiation therapy for another cancer
- Long-standing lymphedema
- Environmental exposures, such as certain chemicals or toxins (e.g., vinyl chloride, arsenic)
- Immunosuppression in organ transplant recipients or patients with HIV
Risk Factors
- Age over 50
- Male gender (slightly higher incidence)
- History of radiation exposure
- Genetic cancer syndromes (e.g., Li-Fraumeni syndrome)
- Chronic lymphedema
- Previous trauma or surgery (as a possible local trigger)
- Occupational exposure to carcinogens
Complications
- Local tissue destruction, including muscle, bone, and nerves
- Metastasis, especially to the lungs
- Recurrence, even after surgical removal
- Functional impairment, especially in limbs or joints
- Pain and swelling as tumor progresses
- Psychological impact due to cancer diagnosis and treatment side effects
Prevention
While UPS cannot be entirely prevented, certain measures can reduce overall cancer risk:
- Avoid unnecessary exposure to radiation and carcinogens
- Use protective equipment in industrial environments
- Routine medical follow-up if previously treated with radiation
- Genetic counseling for individuals with familial cancer syndromes
- Prompt evaluation of unusual lumps or soft tissue masses
Treatment Options in Korea
South Korea offers world-class care for Undifferentiated Pleomorphic Sarcoma with advanced diagnostic imaging, pathology, and specialized cancer treatment centers. Treatment strategies include:
- Surgical excision: Wide-margin surgical removal is the cornerstone of treatment
- Radiation therapy: Often used before or after surgery to reduce recurrence risk
- Chemotherapy: Administered in high-grade or metastatic cases (e.g., doxorubicin-based regimens)
- Targeted therapy or immunotherapy: In clinical trials or specialized centers for advanced or resistant tumors
- Multidisciplinary team management: Combining oncology, surgery, radiology, and pathology expertise
- Rehabilitation services: To restore function and mobility after treatment
- Regular follow-up and imaging: To monitor for recurrence or metastasis
Korea’s oncology infrastructure supports personalized and aggressive treatment plans for UPS with a focus on long-term survival and quality of life.
