What is Alveolar Rhabdomyosarcoma?

Alveolar rhabdomyosarcoma is a rare form of skeletal muscle cancer that primarily affects patients who are under the age of 20. In most cases, tumors manifest within muscles in the arms or legs, but it is possible to develop cancer in the torso or neck as well. Alveolar rhabdomyosarcoma can spread quickly to other muscles and internal organs, and the outlook is best when the cancer is diagnosed and treated in its earliest stages. Most patients who receive prompt medical and surgical treatment are able to experience full recoveries.

There are many different forms of childhood rhabdomyosarcoma that are classified by the parts of the body they affect and the symptoms they cause. Alveolar rhabdomyosarcoma is one of the most common types, making up about 20 percent of diagnosed cases. The term alveolar refers to the physical appearance of affected tissue: cancerous areas are made up of overlapping fibers that create spaces in between muscle cells, resembling alveoli in the lungs.

Doctors are unsure what causes the cancer, but it is believed that most cases are related to either inherited genetic conditions or random mutations that occur during embryonic development. Tumors grow when new muscle cells fail to complete their development and die. Instead, immature cells continue to replicate and spread throughout a section of muscle tissue.

The symptoms of alveolar rhabdomyosarcoma can vary between different patients, depending on the stage of cancer and the location of tumors. Masses on muscles near the skin may form visible, soft, tender lumps. When tumors are deeper within muscle tissue, they are often painful and occasionally debilitating. Symptoms of fatigue and loss of appetite may set in as a tumor grows and the cancer begins to spread to other parts of the body. A patient who does not receive treatment is at risk of developing potentially life-threatening kidney, liver, or lung complications.

A doctor can check for alveolar rhabdomyosarcoma by conducting blood tests, biopsies, and diagnostic imaging scans. Blood samples are evaluated in a laboratory to check for abnormalities, and x-rays may reveal physical tumors within muscle tissue. When a mass is found, a specialist can extract a small tissue sample to either confirm or rule out cancer.

When a tumor is discovered early, surgical removal is usually the best treatment option. Chemotherapy or radiation treatments may be necessary if a tumor cannot be fully removed or if the cancer has already spread elsewhere in the body. Compared to some other aggressive cancers, alveolar rhabdomyosarcoma generally responds well to chemotherapy. Since it is possible for the cancer to return, regular screenings throughout childhood and adolescence are important to prevent recurring problems.