PRIMITIVE NEUROECTODERMAL TUMOR OF THE ORBIT

A 10-year-old girl developed a lump in the lateral aspect of the right eyebrow over a 3-week period. Computed tomography and magnetic resona nce imaging revealed a soft-tissue mass in the superolateral aspect of the right orbit associated with zygomaticofrontal bone erosion and hy perostosis. An incisional biopsy specimen was studied using light micr oscopy, immunohistochemical staining, and electron microscopy, resulti ng in a diagnosis of peripheral primitive neuroectodermal tumor. The r esults of an extensive evaluation for systemic involvement were negati ve. The patient was subsequently treated with chemotherapy and radiati on therapy. Primary primitive neuroectodermal tumor of the orbit is ra re. The differential diagnosis and the diagnostic features of this ent ity are discussed herein.