Les tumeurs d’orbite de l’enfant : examen clinique, paraclinique, diagnostic et particularités évolutives

Abstract

“Orbital tumors (OT) are neoplasms of the bony orbit and contents except for the eyeball.” Given this definition, we exclude the retinoblastomas, which are the most frequent tumors of this anatomical area in the pediatric population. Although these tumors are rare, there is a great variety of etiologies. Among them, the most frequent OTs in childhood are rhabdomyosarcomas and metastatic tumors: metastatic neuroblastomas and leukemias (chloromas). Moreover, adult and pediatric varieties of OT are made up of two clusters of distinctive histological entities. Examination must be careful: measurement, direction of proptosis, impairment of ocular motility, compressive optic neuropathy, strabismus, etc. Age at onset as well as unilateral or bilateral proptosis are important features. Benign tumors such as dermoid cysts or hemangiomas grow slowly, whereas rapid growth suggests a malignant tumor. Fundi and visual acuity should be checked. The general examination focuses especially on cutaneous abnormalities such as café au lait spots and subcutaneous nodules in neurofibromatosis type 1 (NF1), a hemangioma that often involves the cutaneous portion of the eyelid. When a metastatic tumor is suspected, abdominal palpation and ultrasonography must be performed. Ultrasonography leaves the posterior third of the orbit inaccessible to exploration. The depth to which it can penetrate the orbit is limited (20 mm). Most of the time, standard x-rays, CT, and MR imaging allow for an adequate assessment and usually provide a diagnosis. In children, CT and MRI sometimes require anesthesia to be properly performed.