Hemangiopericytoma

Hemangiopericytoma is a rare tumor that grows in the body’s soft tissue, which includes fat, muscles, tendons, nerves, blood vessels, and other fibrous tissue. In a baby, this condition is called infantile myofibromatosis, and the tumors typically go away on their own. In adolescence, the tumor can be benign or malignant; it’s often found in bones, but can spread to the teenager’s lungs.

About 900 children and adolescents are diagnosed with soft-tissue tumors in the U.S. each year.

Because hemangiopericytoma affects tissue that is elastic and easily moved, a tumor may exist for a long time before being discovered, growing large and pushing aside surrounding tissue.

Each child may experience symptoms differently. The symptoms can vary greatly depending on size, location, and spread of the tumor. Here’s a list of some of the symptoms your child may be experiencing:

• A painless swelling or lump
• Pain or soreness
• Limping or other difficulty using her legs or feet
• Hypoglycemia (low blood sugar)

The symptoms can be different in tumors that affect the lungs:

• Cough (with or without blood)
• Pain
• Night sweats
• Difficulty breathing

We don’t know exactly, but studies have indicated that genetic alterations may play a role in the formation of all soft-tissue sarcomas (tumors). In addition, limited studies have shown a possible link between soft-tissue sarcomas and the development of other types of cancer.

In addition to a complete medical history and physical examination, the most conclusive diagnostic procedure for hemangiopericytoma is a biopsy — a single tissue sample taken from the tumor through a simple surgical procedure.

The tumor's cellular appearance under a microscope enables doctors to distinguish it from other types of cancer and determine whether it is malignant or benign. Your child will likely have various imaging studies that will include one or more of the following:

• X-ray
• Bone scans
• Magnetic resonance imaging (MRI)
• Computerized tomography scan (also called a CT or CAT scan)

If your child’s doctor determines that the hemangiopericytoma is malignant, the tumor is staged. This process indicates how far the tumor has spread from its original location. The stage of a tumor and how aggressive the tumor is suggests which form of treatment is most appropriate, and gives some indication of the prognosis. A hemangiopericytoma may be localized, meaning it hasn’t spread beyond the joint where it arose or beyond nearby tissues, or metastatic, meaning it has spread to the lungs, bones, or to other organs or structures of your child’s body.

You'll discuss specific treatment for your child's tumor with your doctor. We've described some of your treatment options below.

Surgery

Surgery includes biopsy and surgical removal of the entire tumor and surrounding healthy tissue. Depending on the location and size of the tumor, it may be necessary to remove all or part of the limb. In most cases, we perform limb-sparing surgery to avoid amputation.

Limb-sparing surgery

It is sometimes necessary to remove all or part of a limb. In most cases, however, limb-sparing surgery is used to avoid amputation. Through limb-sparing surgery, all of the bone and cartilage involved with the tumor, including some degree of muscle surrounding it, is removed, while nearby tendons, nerves, and vessels are saved.

The bone that is removed is replaced with a bone graft or with a metal prosthesis. Subsequent surgery may be needed to repair or replace rods, which can become loose or break. Patients who have undergone limb-sparing surgery need intensive rehabilitation. It may take as long as a year for your child to regain full use of a limb following limb-sparing surgery. Rarely, patients who undergo limb-sparing surgery may eventually have to have the limb amputated because of a severe complication or tumor recurrence.

Amputation

If your child's orthopedic surgeon determines that the tumor cannot be removed because it involves important nerves and blood vessels, amputation is the only surgical option.

During the operation, doctors ensure that muscles and skin form a cuff around the amputated bone. As the swelling decreases (10 to 14 days), your child will be fitted for a plastic, temporary socket and prosthesis, which is used for two to four months until her stump is healed sufficiently to accept a permanent artificial limb.

The advantages of an amputation are that it is a simple operation with minimal chances of surgical complication and it definitively removes the local tumor. The functional outcome is good, since children can use modern prostheses. Children often also use "immediate-fit" prostheses applied in the operating room.

Although your child will probably have a limp with above-the-knee amputations, the procedure is functional and stable. They will be able to walk, climb stairs, swim (with the prosthesis on or off), and participate in many sports, such as skiing, basketball, baseball, and tennis, although running will be limited.

Radiation

This is sometimes used in conjunction with surgery for hemangiopericytoma, either before or after removal of the tumor if it is malignant. On rare occasions, radiation alone is used for treatment of the primary tumor.

Chemotherapy

If the tumor is malignant, chemotherapy may be part of your doctor's recommended treatment. Chemotherapy is a drug treatment that works by interfering with the cancer cell's ability to grow or reproduce.

While chemotherapy can be quite effective in treating certain cancers, the agents don't differentiate normal healthy cells from cancer cells. Because of this, there can be many adverse side effects during treatment. Being able to anticipate these side effects can help the care team, parents, and child prepare and in some cases, prevent these symptoms from occurring, if possible.

The prognosis for your child greatly depends on:

• The extent of the disease
• The size and location of the tumor
• Presence or absence of metastasis
• The tumor's response to therapy
• The age and overall health of your child
• Your child's tolerance of specific medications, procedures, or therapies
• New developments in treatment

Every child is unique and treatment and prognosis is structured around your child's needs. Prompt medical attention and aggressive therapy are important for the best outcome.

Dana-Farber/Boston Children’s Cancer and Blood Disorders Center provides compassionate, comprehensive medical and surgical care for children and adolescents with benign or malignant soft tissue tumors through our Bone and Soft Tissues Tumors Program. Our multidisciplinary approach to care ensures in-depth discussion of each case and personalized treatment plans for every child.