Rhabdomyosarcoma is an uncommon form of cancer that primarily affects children and adolescents. It arises from cells that resemble skeletal muscle and therefore develops in or near areas composed of muscle tissue. Although it originates from muscle-like precursor cells, tumors may appear in many parts of the body and are often found where muscles that move the body attach to bones.

Overview

Rhabdomyosarcoma belongs to the group of soft-tissue sarcomas. Because it can grow in various locations, symptoms depend on the tumor's site and size. Management typically involves several specialties and combines local control (surgery and/or radiotherapy) with systemic chemotherapy.

Common signs and symptoms

  • A lump or swelling that may be painless at first
  • Symptoms caused by compression of nearby structures (for example, breathing or vision problems when the tumor is in the head or neck)
  • Urinary or bowel changes if the tumor involves the genitourinary tract
  • Pain or reduced movement when limbs are involved

Major types

There are several histologic categories, but three classic subtypes are most often described:

  1. Embryonal — the most frequent form in young children and generally associated with a better prognosis than some other types.
  2. Alveolar — more common in older children and adolescents; it tends to be more aggressive.
  3. Pleomorphic — typically seen in adults and less common in the pediatric population.

Diagnosis

Evaluation usually begins with imaging (ultrasound, CT, or MRI) to define the tumor extent, followed by a biopsy to establish the diagnosis and subtype. Additional studies may include tests to determine whether the disease has spread.

Treatment

Decisions about therapy depend on the tumor's location, size, subtype, and whether it has metastasized. Standard treatment approaches often combine:

  • Surgery to remove the tumor when feasible
  • Chemotherapy to treat microscopic or overt systemic disease
  • Radiation therapy for local control when complete surgical removal is not possible or when margins are positive

Prognosis and follow-up

Outcomes vary widely. Factors that influence prognosis include the histologic subtype, tumor site, size, the presence of metastases at diagnosis, and the patient’s age. Long-term follow-up is important to monitor for recurrence and to manage late effects of therapy.

Clarification

Rhabdomyosarcoma is distinct from rhabdomyolysis, a completely different condition in which skeletal muscle breaks down and releases its contents into the bloodstream.