What are the other Names for this Condition? (Also known as/Synonyms)

• Congenital Fibrosarcoma
• Desmoplastic Fibrosarcoma of Infancy
• Fibrosarcoma of Soft Tissue - Infant

What is Infantile Fibrosarcoma? (Definition/Background Information)

• Infantile Fibrosarcoma (IFS) is a malignant tumor of infancy that is typically seen in children below age 1. It is an aggressive and rapidly developing tumor that can grow to large sizes
• There are no identified risk factors for Infantile Fibrosarcoma, but the cause is associated with genetic aberrations. Specifically, the presence of ETV6 and NTRK3 gene fusion is characteristic of IFS
• The most common site of the tumor is the arms and legs followed by the trunk. Large Infantile Fibrosarcomas can cause skin ulceration, apart from anemia due to hemorrhaging/bleeding of the tumor
• The treatment of Infantile Fibrosarcoma may include a combination of surgery, chemotherapy and radiation therapy, based on the assessment by the healthcare provider
• With appropriate early treatment, the prognosis of Infantile Fibrosarcoma is generally good. However, the prognosis is dependent upon a set of factors that includes the size and location of the tumor, the organs affected, etc.

Who gets Infantile Fibrosarcoma? (Age and Sex Distribution)

• Most cases of Infantile Fibrosarcoma are seen within the first 12 months of birth; almost all cases have been documented in children younger than 2 years
• Between 36-80% of the cases are noted at birth (congenital presentation)
• Both boy babies and girl babies are affected, but there is a slight male predilection
• All racial and ethnic groups may be affected

What are the Risk Factors for Infantile Fibrosarcoma? (Predisposing Factors)

• Currently, there are no specific risk factors associated with Infantile Fibrosarcoma

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 Infantile Fibrosarcoma? (Etiology)

The exact cause of Infantile Fibrosarcoma formation is not known. However, the following genetic anomalies have been observed:

• The involvement or fusion of genes ETV6 and NTRK3 have been noted. Studies inform that this is a very specific indicator for Infantile Fibrosarcoma
• IFS shows chromosomal translocations; chromosomes 8, 11, 17, 20 may reveal trisomy

What are the Signs and Symptoms of Infantile Fibrosarcoma?

The signs and symptoms of Infantile Fibrosarcoma may include:

• Presence of a single tumor that shows rapid growth and enlargement
• The tumor can appear very large for the region affected (disproportionate in size)
• It can grow up to 30 cm in size (along larger dimension); the skin over large-sized tumors can turn red and ulcerate
• Studies can show an infiltrative soft tissue mass that is poorly-circumscribed with irregular margins
• IFS can be found below the skin or deep in the tissues; frequent sites include the distal extremities (arms and legs) in 65% of the cases
• Other major sites are the chest, back, and head and neck region. It is rare to find the tumors in the body organs

How is Infantile Fibrosarcoma Diagnosed?

A diagnosis of Infantile Fibrosarcoma may involve the following tests and exams:

• A physical examination and evaluation of complete medical history
• Imaging studies, such as X-rays, CT and MRI scans, of the affected region
• Tissue biopsy of the tumor:
  • A tissue biopsy is performed and sent to a laboratory for a pathological examination. A 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
  • Fluorescence in situ hybridization (FISH) and polymerase chain reaction (PCR) tests can help in the diagnostic evaluation process
  • Molecular analysis of the tumor to detect the fusion of ETV6 and NTRK3 genes; finding this particular mutation can help confirm a diagnosis of IFS
  • Examination of the biopsy under a microscope by a pathologist is considered to be gold standard in arriving at a conclusive diagnosis
• Prenatal scans may reveal the presence of the tumor, since the tumor is known to be present in newborn infants (congenital condition)

Note: Some case reports have indicated that during examination, Infantile Fibrosarcoma may be present along with infantile myofibroma (composite tumors).

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 Infantile Fibrosarcoma?

The possible complications from Infantile Fibrosarcoma include:

• Severe emotional distress (for the parents) due to the presence of large-sized tumors
• Anemia can occur due to hemorrhage (bleeding) of the tumor
• Ulceration of the skin can cause secondary bacterial, viral, or fungal infections
• Skeletal muscle and fatty tissue destruction along with bone erosion, which may be visible through imaging modalities
• In rare cases, the tumor may be seen in the kidneys, a condition known as cellular congenital mesoblastic nephroma (CMN)
• Surgically excised tumors are known to return; the recurrence rate varies from 5% to 50%
• Metastasis or spread of the cancer is noted in rare cases
• Damage to vital nerves, blood vessels, and surrounding structures during surgery to remove the tumor
• Side effects from chemotherapy and radiation therapy; chemotherapy can cause scarring or thickening of tissues (fibrosis)

How is Infantile Fibrosarcoma Treated?

Treatment measures for Infantile Fibrosarcoma may include the following:

• Surgical excision of IFS with removal of the entire tumor is generally adopted; multiple surgeries may be necessary
• Embolization is 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 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
• Very rarely, a spontaneous regression of the tumor has been observed
• Follow-up care with regular screening and check-ups are important

How can Infantile Fibrosarcoma be Prevented?

• Current medical research has not established a way of preventing Infantile Fibrosarcoma
• Regular medical screening at periodic intervals with blood tests, scans, and physical examinations are mandatory due to its metastasizing potential and chances of recurrence. Often several years of active vigilance is necessary

What is the Prognosis of Infantile Fibrosarcoma? (Outcomes/Resolutions)

• The prognosis of Infantile Fibrosarcoma is generally good with appropriate early treatment. Studies indicate that the mortality rate is not more than 5%
• Though the tumor recurrence rate is moderate to high; occasionally, even incompletely removed tumors do not seem to recur
• Poor prognosis is associated with severe tumor bleeding and key organs being affected by the presence of aggressive tumors; these factors can potentially result in fatal outcomes

Additional and Relevant Useful Information for Infantile Fibrosarcoma:

Fibrosarcomas that occur in adults and children are histologically similar to each other.