Malignant soft tissue tumors, also known as sarcomas, are a type of cancer that affects the connective tissue in the body (fat, cartilage, ligaments, blood vessels, muscles, tendons, and the cells that create bone tissue. They are an extremely rare form of cancer and accounts for less than one percent of all cancer diagnoses in the United States each year. There are many different subtypes, depending on where it originates and the pathology of the tumors (how they look and behave when viewed under a microscope), among other factors.
While anyone can technically develop a sarcoma, there are some forms that are more common in children, and some that are more likely to affect middle-aged and older adults. Connective tissue runs throughout the body, and therefore tumors can develop anywhere in the body, but many forms are most common in the long bones of the arms and legs, especially in childhood, making limb preservation an important part of treatment.
What Causes Malignant Soft Tissue Sarcomas?
A direct cause for malignant soft tissue tumors has not been clearly identified, but as with all cancers, there are certain factors that can increase the risk of developing it, such as genetics, environmental factors like prolonged exposure to certain industrial chemicals and pesticides, and having undergone previous radiation treatments for cancer. Certain genetic conditions that are passed down to children from their parents may increase the risk of developing soft tissue cancers. The conditions associated with a genetic predisposition to sarcomas include:
- Werner syndrome
- Familial adenomatous polyposis
- Hereditary retinoblastoma
- Tuberous sclerosis
- Li – Fraumeni syndrome
What are the Symptoms of Soft Tissue Sarcomas?
Connective tissue tumors rarely produce symptoms in the early stages, making them somewhat difficult to diagnose. When symptoms do present, it is typically in the form of a painless lump. Pain can result if the tumor is pressing against or applying pressure on a nerve.
Sarcoma Grading and Staging
Sarcomas are assigned a grade (from low to high) at diagnosis to specify how aggressive and likely the tumor is to spread (metastasize) to other parts of the body. Low-grade tumors are slow growing and the least likely to metastasize, while high-grade tumors are generally more likely to spread, and have the least amount of normal tissue when viewed under a microscope. Tumor grading helps the oncologist to determine the best course of treatment in each case, along with a number of other factors specific to each patient.
Tumors can also be further categorized by stage, ranging from I – IV. Tumor size does not correspond with the stage. A large tumor may still be low grade and stage I, meaning that it is slow growing and has not spread beyond the area of the body in which it developed. In many cases, surgery alone is sufficient to remove the tumors and a degree of surrounding normal tissue to study what is known as the margins to help determine whether any cancerous cells were potentially left behind after surgery and whether radiation and/or chemotherapy should be prescribed as well.
Stage II and III refers to tumors that have spread from the primary site to the lymph nodes. They carry a greater risk of spreading to distant tissue and organs, and of returning (recurrence) after they have been removed.
Stage IV refers to tumors that have spread to distant organs like the lungs.
Types of Malignant Soft Tissue Tumor
Tumors of the connective tissue can be both benign (non-cancerous) and malignant. Tumors categorized as sarcomas are malignant. Some tumors can be somewhere in between a sarcoma and a benign tumor, which is categorized as an intermediate tumor. There are as many as 50 different types of soft tissue sarcomas. Some of the most commonly diagnosed are:
- Alveolar soft part
- Adult fibrosarcoma
- Neurogenic sarcomas
- Undifferentiated pleomorphic
- Clear cell
- Malignant fibrous histiocytoma (MFH)
- Malignant peripheral nerve sheath tumor
- Malignant schwannomas
- Malignant mesenchymoma
- Gastrointestinal stromal tumor (GIST)
- Desmoplastic round cell tumor
Intermediate Soft Tissue Sarcomas include:
- Solitary fibrous tumor
- Desmoid tumor
- Infantile fibrosarcoma
- Dermatofibrosarcoma protuberans
- Musculoaponeurtoic fibromatosis
Sarcoma Treatment in Los Angeles
Due to the rarity of this type of cancer, finding an oncologist with a specialization in connective tissue tumors and limb preservation can be challenging, and many general oncologists can go through an entire career without encountering a sarcoma case. Dr. Allison has extensive experience in early detection, limb preservation, and specialized treatment in bone and soft tissue sarcoma.
Treatment will depend on the type, grade, and location of the tumor, as well as the patient’s overall health and pathology report (collection of test results and health profile) among other factors. The most common treatments are surgery, radiation, and chemotherapy.
Contact an Orthopedic Oncologist in Los Angeles
Soft tissue and bone sarcomas are very rare forms of cancer. Working with a sarcoma specialist with diagnostic, treatment, and limb preservation experience is very important. For more information, contact board-certified orthopedic surgeon Dr. Daniel C. Allison by calling 310-730-8008 to schedule an appointment today.
Next, read Benign Bone Tumors