By Paul T. Finger, MD
Rhabdomyosarcoma is the most common primary malignancy of the orbit in children. It can also occur in adults, though the average age of patients affected by rhabdomyosarcoma is 7 – 8 years.
Most parents first notice a droopy eyelid (called ptosis), and that the eye is more prominent (called proptosis), or that their child has a tumor under the conjunctival membrane that covers the eye (globe). Rhabdomyosarcoma is usually found in the superonasal orbit (that is under the upper lid near the nose).
Computed axial tomography (CT-scan) and magnetic resonance imaging (MRI) typically show a mass adjacent to or attached to one of the ocular or orbital muscles. CT is particularly helpful because it offers the best evidence if the orbital bones have been invaded by the rhabdomyosarcoma tumor.
Rhabdomyosarcoma can grow rapidly and if the tumor grows into the brain or spreads to the lung, survival is poor. Prompt biopsy of a rhabdomyosarcoma followed by a combination of chemotherapy and irradiation offers the best chance of survival. In fact, recent reports suggest that current treatments offer greater than 90% survival from rhabdomyosarcoma.
Patients will develop problems typically seen after chemotherapy and irradiation of the eye, but if there is no recurrence after 3 years, it is likely that the rhabdomyosarcoma has been controlled.