What are the other Names for this Condition? (Also known as/Synonyms)
- MFS (Myxofibrosarcoma)
- Myxoid Malignant Fibrous Histiocytoma
- Myxoid MFH
What is Myxofibrosarcoma? (Definition/Background Information)
- Myxofibrosarcoma (MFS) forms a group of malignant soft tissue tumors that are commonly observed in older adults. It is also referred to as Myxoid Malignant Fibrous Histiocytoma
- Morphologically, these tumors may be classified as high grade, intermediate-grade, or low-grade. The cause of Myxofibrosarcoma occurrence is unknown and no risk factors have been reported
- A majority of the tumors involve the arms and legs, though it typically avoids the hands and feet. The presence of an infiltrating mass with an absence of pain is noted. Myxofibrosarcoma may be located subcutaneously or deep in the body tissues
- The treatment of choice for Myxofibrosarcoma is a complete surgical excision. Since tumor recurrence and metastasis is commonly noted, radiation therapy and/or chemotherapy may be necessary
- The prognosis of Myxofibrosarcoma depends upon several factors including the size and grade of the tumor. Generally, low-grade and small-sized tumors that are detected early and can be completely removed have a good prognosis
Who gets Myxofibrosarcoma? (Age and Sex Distribution)
- Myxofibrosarcoma mainly affects older adults in the 50-80 year age range (average age 66 years). However, adults of a wide age range may be affected
- It is very difficult to observe Myxofibrosarcomas in individuals below 20 years of age i.e., in children and very young adults
- Both males and females are affected, though a slight male predominance is seen
- There is no known ethnic or racial preference noted
What are the Risk Factors for Myxofibrosarcoma? (Predisposing Factors)
- Currently, the specific risk factors for Myxofibrosarcoma are yet to be identified
It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases ones chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.
Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.
What are the Causes of Myxofibrosarcoma? (Etiology)
- The exact cause and mechanism of formation of Myxofibrosarcoma is unknown
- Some reports indicate that they may occur due to genetic defects
- A minority of the tumors (about 1 in 10 tumors) display gene mutations and deletions similar to those seen in neurofibromatosis type 1 (NF1)
- NF1 is a genetic disorder affecting the skin and other body systems. Research is being undertaken to determine the significance of such similar mutations
What are the Signs and Symptoms of Myxofibrosarcoma?
The signs and symptoms of Myxofibrosarcoma include:
- Presence of a slowly-growing mass is observed; no pain is generally noted
- The tumors may be sited just below the skin surface or in the deep tissues. 50-65% of the tumors affect the skin/subcutaneous region; the remaining 35-50% are found deeper in the tissues or muscles
- Tumors just below skin are often multinodular in appearance; those that are deeper are often present as a single infiltrating mass. Sometimes, the extent of tumor spread may be difficult to determine due to severe tumor infiltration
- Most tumors affect the arms and legs (especially the limb girdle); legs are affected more than the arms. However, hands and feet are only rarely affected
- Rarely, Myxofibrosarcoma have been observed on the chest and back (trunk), head and neck region. Abdominal or retroperitoneal tumors are also seen very rarely
Note: Myxofibrosarcomas may be low-grade, intermediate-grade, or high-grade. The higher the tumor grade, the greater is the chance of infiltrative behavior and metastasis (spread to other body parts). Low-grade Myxofibrosarcoma tumors are not known to metastasize.
How is Myxofibrosarcoma Diagnosed?
A diagnosis of Myxofibrosarcoma may involve the following tests and exams:
- Complete physical examination and evaluation of medical history
- MRI or CT scan of the affected region to aid in obtaining a clear image of the tumor, prior to surgery
- Tissue biopsy of tumor specimen: A tumor biopsy is performed and sent to a laboratory for a pathological examination. The pathologist examines the biopsy under a microscope. After putting together clinical findings, special studies on tissues (if needed) and with microscope findings, the pathologist arrives at a definitive diagnosis
Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.
What are the possible Complications of Myxofibrosarcoma?
The complications of Myxofibrosarcoma may include:
- Higher grade tumors show metastasis to the lungs and bones. Higher and intermediate grade tumor metastasis rate varies from 20-35%
- Even though, spread of the tumor to the lymph nodes is rarer, a significant number of cases have presented lymph node metastasis
- Tumor recurrence following surgical excision and removal
- In some cases, multiple recurrences are noted; also, the tumor may move to a different (usually higher) grade when it returns. This feature is noted in about 60-70% of the cases
- Damage of vital nerves, blood vessels, and surrounding structures, during surgery
- Side effects from chemotherapy (toxicity) and/or radiation therapy
How is Myxofibrosarcoma Treated?
The treatment of Myxofibrosarcoma is undertaken as follows:
- Wide surgical excision of MFS with removal of the entire tumor is generally adopted. However, often a complete excision is difficult due to infiltrative growth and involvement of surrounding tissue structures
- Embolization (clotting the vessels in the tumor) may be used to provide temporary relief from the symptoms and reduce blood loss during a surgical procedure
- Radiation therapy and/or chemotherapy may be used to destroy the remaining tumor cells, based on the assessment by the healthcare provider
- Post-operative care is important; a minimum activity level is to be ensured until the surgical wound heals
- Follow-up care with regular screening and check-ups are important; a long-term follow-up is recommended
How can Myxofibrosarcoma be Prevented?
- Current medical research have not established a way of preventing Myxofibrosarcoma
- Regular medical screening at periodic intervals with blood tests, scans, and physical examinations, are mandatory for those who have already endured the tumor, due to its metastasizing potential and possibility of recurrence. Often several years of active vigilance is necessary
What is the Prognosis of Myxofibrosarcoma? (Outcomes/Resolutions)
- Myxofibrosarcoma is a malignant tumor that can display local aggression and metastatic behavior. In general, the 5 year survival rate is about 60% to 70%
- The prognosis depends on a combination of factors including:
- Age of the individual
- Grade of the tumor: A higher grade means a greater chance of metastasis and a poorer prognosis
- Tumor stage at detection
- Tumor size and location
- Individual’s response to therapy
- Tumors that are small in size and at easily accessible locations generally have a good prognosis on complete surgical excision and removal. Late detection of tumors may present with metastasis, which can adversely affect the prognosis
- If the tumor recurs within a year of surgical removal, then it is an indicator of poor prognosis with increased mortality rates. Nevertheless, if the tumor is confined to its site of origin, then a better prognosis may be ensured
- According to studies, the key indicators of outcome include tumor size and grade, and the presence of infiltrating margins
- Also, low-grade tumors may turn into high-grade tumors following treatment (removal), which can be associated with metastasis and consequently poorer outcomes
Additional and Relevant Useful Information for Myxofibrosarcoma:
- A majority of abdominal and retroperitoneal tumors which resemble Myxofibrosarcoma are actually dedifferentiated liposarcomas
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