Myxofibrosarcoma is a rare and malignant tumor that develops in soft tissues. It can form near the surface of the skin or deeper within the body. These tumors most commonly occur in the legs, particularly the thighs, but they can also appear in the arms, head, neck, chest, abdomen, pelvis, and back.
Unlike some sarcomas that push surrounding tissues aside, myxofibrosarcomas infiltrate and damage nearby tissues. Their growth rate varies depending on their grade, which reflects how the tumor cells appear under a microscope. Some tumors develop slowly, while others grow more aggressively.
A significant challenge with myxofibrosarcoma is its tendency to return after treatment. The tumor’s indistinct edges make complete removal difficult. When it recurs, it has an increased risk of metastasizing to the lymph nodes or lungs. Researchers are actively working to improve methods for predicting recurrence risks.
Myxofibrosarcoma is rare, with fewer than 500 cases diagnosed annually in the U.S., accounting for about 5% of new soft tissue sarcomas. Most cases occur in individuals over the age of 50.
Symptoms of Myxofibrosarcoma
Myxofibrosarcoma tumors may not cause symptoms initially. However, as they grow, they can produce noticeable signs, depending on their location:
- Abdominal discomfort, bloating, constipation, or increased urination
- Pain in the affected area
- Swelling near the skin
Causes and Risk Factors
The exact cause of myxofibrosarcoma remains unknown. For other soft tissue sarcomas, risk factors include previous radiation therapy, inherited genetic mutations, and occupational exposure to certain chemicals. However, researchers have not yet determined whether these factors contribute to myxofibrosarcoma. Currently, there are no known preventive measures for this cancer.
Diagnosing Myxofibrosarcoma
Diagnosing myxofibrosarcoma can be challenging. Many cases are misdiagnosed or experience delays in detection. The cancer may be mistaken for benign tumors, melanoma, or other soft tissue sarcomas. A definitive diagnosis requires a tissue sample obtained through an image-guided needle biopsy. Pathologists examine the sample under a microscope to classify the tumor’s grade. Low-grade tumors have slow-dividing cells and are less likely to recur, while high-grade tumors have rapidly dividing cells and higher recurrence risk. Findings from the physical exam, imaging scans, and biopsy results help the medical team determine the stage of the disease and develop an appropriate treatment plan.
Treatment for Myxofibrosarcoma
Surgical removal is the primary treatment for myxofibrosarcoma. The best surgical outcome occurs when the tumor is excised in one piece, along with a margin of healthy tissue. This approach minimizes the risk of recurrence. To further reduce recurrence chances, radiation therapy is often recommended before surgery.
The prognosis depends on tumor size, grade, and location. If myxofibrosarcoma recurs or spreads, additional treatment options such as chemotherapy may be considered.
Emerging therapies show promise for myxofibrosarcoma treatment. Some tumors respond to immunotherapy, which strengthens the body’s immune system to fight cancer. Others may be susceptible to targeted therapies that focus on specific cancer cell growth pathways. Ongoing sarcoma clinical trials are investigating these advanced treatment strategies.
Resources:
Penn Medicine
