What Is It?
Rhabdomyosarcoma is an uncommon cancer that is seen in children more than adults. It is in the class of soft-tissue tumors. Rhabdomyosarcoma typically appears in one of three locations: the head and neck region (35 percent to 40 percent of cases), the urinary tract and reproductive organs (25 percent of cases) or the arms and legs (10 percent of cases). It also can occur on the trunk. In about two-thirds of cases, rhabdomyosarcoma occurs in a child younger than 10. Based on subtle variations in microscopic appearance, doctors can classify rhabdomyosarcomas into several varieties. Most rhabdomyosarcomas are either embryonal (60 percent of cases) or alveolar (20 percent of cases).
- Embryonal — These tumors tend to develop at the back of the throat, in the ear canal or in the urinary or reproductive tracts. In general, embryonal rhabdomyosarcoma is a limited, localized cancer that responds well to treatment and rarely spreads (metastasizes).
- Alveolar — These tumors tend to be aggressive and hard to treat. They often begin in the arms and legs, especially in older children and teen-agers.
In the United States, rhabdomyosarcoma strikes approximately five in every 1 million children each year. Children are more likely to develop rhabdomyosarcoma if they already have Li-Fraumeni syndrome or neurofibromatosis (type I), or if they have an older relative who has been diagnosed with early-onset breast cancer or adrenal cancer. Rhabdomyosarcoma is also more common in children whose parents have used recreational drugs, especially marijuana or cocaine, and whose fathers smoke.
Symptoms depend on where the tumor develops:
- Head and neck — When rhabdomyosarcoma affects the eye or eyelid, it can cause a bulging eye, a swollen eyelid or paralysis of the eye muscles. In the sinuses, rhabdomyosarcoma can cause a stuffy nose, sometimes together with a nasal discharge that contains pus or blood. In other locations in the head and neck, the most common symptom of a superficial rhabdomyosarcoma is a painless lump or swelling that enlarges gradually. A rhabdomyosarcoma located deep in the skull can erode the bones that protect the brain, triggering headache and nausea as the tumor gradually grows toward the brain’s surface.
- Genitourinary tract — Rhabdomyosarcomas can develop in the bladder, prostate, vagina, uterus, scrotum and testes. Depending on their exact location, these tumors can cause difficulty in urination, hematuria (blood in the urine), constipation, a lump or mass inside the vagina, vaginal discharge that contains blood and mucus, or painless enlargement of one side of the scrotum.
- Arms and legs — In this location, rhabdomyosarcoma appears as a lump or swelling in an arm or leg, with or without pain, tenderness and redness. In physically active children, the swelling is sometimes mistaken for an injury related to sports or childhood play.
After reviewing your child’s symptoms, your doctor will perform a thorough physical examination with special attention to the affected area of your child’s body. Then, depending on the results of this exam, your doctor may order a regular X-ray as the first test. Computed tomography (CT) scans and magnetic resonance imaging (MRI) might also be done.
If diagnostic tests show signs of a malignant tumor, your doctor will refer you to a major medical center that has the facilities, personnel and experience to treat childhood cancer. There your child will have further tests, which probably will include a chest X-ray, a chest CT scan, a radionuclide bone scan, a bone-marrow biopsy and other tests to check whether the cancer has spread to the lungs, bones or elsewhere. Ultimately, your child also will need a biopsy of the affected area to confirm the diagnosis and to determine the exact variety of rhabdomyosarcoma. In a biopsy, a small piece of tissue is removed to be examined in a laboratory.
Rhabdomyosarcomas are rare, and they can produce symptoms that mimic more common conditions, such as bladder infections, sinusitis or sports injuries. For this reason, your doctor may not suspect cancer at first. In fact, in many cases, several months pass before the true diagnosis is made.
A rhabdomyosarcoma will continue to grow until treatment is provided. Without proper treatment, this cancer eventually may spread to the lungs, bone marrow, bones or lymph nodes.
There is no way to prevent most cases of rhabdomyosarcoma. However, any couple that hopes to conceive a healthy child should avoid using recreational drugs and smoking tobacco. These dangerous chemicals could increase the risk of rhabdomyosarcoma or other medical conditions in the child, either at birth or later in life.
The treatment of rhabdomyosarcoma is determined two factors:
- Tumor stage — A tumor’s stage is determined by its location, size and the extent of metastasis (spread) to nearby lymph nodes or to distant organs.
- Tumor group — This is established after surgery has been performed to remove as much of the tumor as possible. In group 1 tumors, the cancer is completely removed surgically. In group 2 tumors, all visible cancer is removed surgically, but some microscopic cancer remains. In group 3, surgery could not remove all visible tumor, but the cancer had not spread. In group 4, the cancer had spread at the time of diagnosis.
Except for tumors located in the eye or genitourinary tract, the first step in treating most rhabdomyosarcoma is surgery. Surgery is followed by chemotherapy and radiation. For very large tumors, chemotherapy and radiation are given before surgery to shrink the tumor, so that the surgery will be less disfiguring.
In the eye, rhabdomyosarcoma usually is treated with radiation and chemotherapy, without surgery. For rhabdomyosarcoma in the bladder or female reproductive tract, chemotherapy and radiation are used to shrink the tumor before surgery. This allows the surgeon to preserve as much of affected organ as possible.
When To Call A Professional
Call your doctor promptly if your child develops a persistent lump or swelling anywhere in the body, especially around the eye, on the face or neck, on an arm or leg, within the vagina or near a testicle. Also, call your doctor if your child has bloody urine, difficulty urinating, pain during urination or a persistent unexplained discharge from the nose, ear or vagina.
The prognosis depends on the tumor group. With treatment, more than 80 percent of children with group 1 rhabdomyosarcoma survive disease-free. Unfortunately, this percentage drops to about 50 percent for children in groups 2 and 3, and less than 20 percent for those in group 4. In general, children with the embryonal variety of rhabdomyosarcoma respond better to treatment than those with the alveolar type. If rhabdomyosarcoma does not respond adequately to treatment, the child will die of the disease.
Diseases and Conditions Center
All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.