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)