The only way the physician can determine your child definitely has rhabdomyosarcoma is to examine a piece of the tumor after surgery. The type of operation your child will have depends on the site of the tumor. If the tumor is in an inaccessible site, such as the eye or ear, the surgeon will just take a very small piece for diagnosis to avoid damaging the surrounding structures.
Your child may have X-rays and scans before surgery to help the surgeon see the extent of the tumor. The piece of tissue obtained at surgery is examined carefully under the microscope. Sometimes it is difficult to diagnose exactly which type of cancer is present, because rhabdomyosarcoma can spread in three ways:
- By direct extension. The tumor stays in its original site and location and grows until it comes into contact with another organ or tissue which it invades.
- Via the lymphatic system to the lymph nodes.
- By invading the bloodstream and spreading to any area of the body. Rhabdomyosarcoma tends to spread or metastasize to the lungs, liver, bone, and bone marrow. Tumors involving the ear, nose, or sinus have a tendency to spread into the central nervous system.
Staging is determined by how far the tumor has spread in your child's body. The doctor determines the staging of your child's tumor by looking carefully to see if other organs or lymph nodes are involved. X-rays, CT scans, PET scans, bone scans and MRIs are used to check the areas of the body to which rhabdomyosarcoma tends to spread, such as the liver, lungs and bones.
Bone marrow aspirations and biopsies are done to assess spread to the bone marrow. A spinal tap may be indicated if the tumor is in the ear, sinuses, or nose. CT or MRI of the brain will also be taken, because tumor in these sites has a tendency to spread to the brain.