Imaging of Orbital Tumors
Rhabdomyosarcoma (RMS) is the most common extraocular malignant tumor in
pediatric patients. Patients often present with a drooping eyelid with
proptosis. A superonasal quadrant location is typical. Additional
malignant masses including leukemia, lymphoma (especially Burkitt’s
lymphoma) and Langerhans cell histiocytosis (LCH) may similarly present
with proptosis. Ocular involvement may occur especially with leukemia.
An inflammatory presentation with a painful, edematous, erythematous
mass lesion may occur with LCH. Infantile hemangiomas present within the
first months of life. Lacrimal gland tumors are exceedingly rare in the
pediatric population. Neuroblastoma is the most common metastatic tumor
to the orbit in children3.
Imaging in Orbital
Tumor Staging
Staging of orbital RMS, like all other RMS in the head and neck, is via
the Intergroup Rhabdomyosarcoma Study Group (IRSG)9. Imaging plays a
critical role in clinical risk grouping of patients in the IRSG.
Staging of orbital RMS is recommended to occur via the IRSG staging
system. (GRADE A, SOR 1.08, very strong recommendation)