Purpose or Case Report: Imaging description of causes for Pediatric Proptosis
Methods & Materials: Discuss the role of imaging in investigation of proptosis in pediatric patients, correlating etiology and anatomical compartments.
Results: Proptosis in children is caused by a spectrum of etiologies often different from those encountered in the adult population. Imaging is important in determining the etiology and planning treatment. Clinical characterization of proptosis (uni- or bilateral, axial or extra axial displacement, visual acuity etc) provides valuable information, is often helpful in image interpretation. True proptosis must be distinguished from pseudo proptosis (i.e., relative disparity in the globe size and the orbital space). Proptosis then can occur secondary to developmentally reduced orbit size, or mass effect associated with a normal size orbit, displacing the globe.
Pediatric pathologies causing globe displacement in the setting of normal orbit size include infectious and non-infectious inflammatory conditions, such as dysthyroid orbitopathy, pseudotumor, developmental conditions such as dermoid, vascular malformations and hamartoma; these benign causes for proptosis constitute 85% of all cases in the pediatric population. Retinoblastoma, the most common pediatric intraocular tumor and rhabdomyosarcoma are the most common malignant causes for proptosis which are unique for the pediatric population. Other neoplastic causes of proptosis include metastasis from neuroblastoma, granulocytic sarcoma from acute myelogenous leukemia optic nerve glioma- juvenile pilocytic astrocytomas. These conditions differ in terms of their treatment and in the eventual visual outcome. An imaging algorithm based on the anatomical compartment, helpful in determining the origin of the lesion is delineated in the exhibit. Lesions are discussed including specific imaging characteristics that help in arriving at the accurate diagnosis.
Conclusions: Imaging plays an important role in defining the cause of proptosis in the pediatric patient; characterization of which guides treatment with the goal of minimizing the impact on vision and health of pediatric patients.