Myxofibrosarcoma is a soft tissue malignant sarcoma. It is also referred as a myxoid variety of malignant fibrous histiocytoma (MFH). Myxofibrosarcoma is invariably seen in elderly people typically involving arm and legs. The tumor is observed more in legs than in arms. It occurs more frequently in skin layer and subcutaneous tissues than in the deeper soft tissues.
Myxofibrosarcoma is classified into three forms; High grade, intermediate grade and low grade tumor. Low grade myxofibrosarcoma has lesser tendency to metastasize while high grade has increased risk of metastasis. Myxofibrosarcoma occurs as an infiltrating mass but there is no associated pain.
The exact cause of this condition is not known. Treatment consists of complete removal of the malignant mass. As the tumor is known for frequent recurrence and metastasis, radiation and chemotherapy is necessary even after its surgical removal.
What Causes Myxofibrosarcoma?
Myxofibrosarcoma as mentioned earlier is a sarcoma of soft tissue. It is malignant growth. The exact cause of this growth is not known. But some researchers believe it may develop due to defect in genes. This therapy is based on certain finding that at least one out of ten tumors of this origin is known to have genetic mutation as similar to other form of fibromatosis called neurofibromatosis type1.At present there is no risk factor determined that is responsible for myxofibrosarcoma.
The malignant growth is usually present in older people. People between the ages of 50 and 80 can be affected. The disease is not observed among people under the age of 20 years. It can develop in men as well as women, but it may have slight predominance among males.
Signs And Symptoms Myxofibrosarcoma
Myxofibrosarcoma can present as follows:
- It is mainly present in older people.
- The mass grows very slowly over a period of time.
- It is a painless malignant mass.
- Most common site is arms and legs but it is rarely present in hands and feet. In some rare cases the tumor may grow on chest, back and trunk.
- This soft tissue tumor is mainly observed under the skin surface or in deeper tissues and muscles. At least 50 to 70 percent of myxofibrosarcoma are under skin and subcutaneous layer. The rest may be present in deeper tissue and muscles.
- Tumors that are present under the skin are multinodular. Whereas deep seated tumor are usually solitary infiltrated mass.
- In some cases the extent of infiltration is not determined due to its extensive penetration into deeper muscles.
Complications Of Myxofibrosarcoma
Myxofibrosarcoma has many complications. A high grade tumor may cause metastasis in lungs and bones. In rare cases it can also spread to lymph nodes. There is high rate of recurrence of the myxofibrosarcoma after its surgical removal. Often there are multiple recurrences.
The recurrent tumor may be of higher grade. For example if the first one was low graded tumor, the recurrent tumor may be more severe and may be of high grade. The growing size of tumor can cause damage to the nearby nerves and blood vessels. It may compress the surrounding structures.
Treatment For Myxofibrosarcoma
Myxofibrosarcoma is a frequently encountered soft tissue tumor particularly in elderly age group. It mostly occurs in extremities. Myxofibrosarcoma is a malignant tumor hence it needs to be treated effectively. The common treatment measure is to remove the mass with surgical intervention. But sometimes complete removal of mass is not possible because the mass may have penetrated deep inside the surrounding tissues and structures.
Often in such cases embolization (clotting) of the blood vessels that supply to the tumor is adopted way of treatment. The intention is to retard the growth. After surgery radiation and chemotherapy are instituted to destroy the remaining tumor cells.
The prognosis of disease depends on the grade of tumor. High grade tumor has potential to metastasize in bones and lungs. In such case the prognosis is poor.