[Recurrence of peripheral primitive neuroectodermal tumor of the orbit with systemic metastases].
CASE REPORT: A six-year-old boy presented with proptosis of the right eye. Imaging studies detected a mass in the medial wall of the right orbit. This mass was biopsied revealing a histopathologic diagnosis of primitive neuroectodermal tumor, so chemotherapy treatment was given. After seven years in remission he presented with a recurrence of the orbital tumor and was found to also have systemic metastases. Treatment with chemotherapy, radiotherapy and orbital exenteration was unsuccessful. DISCUSSION: The orbital occurrence of these tumors is extremely rare. Differentiation from other small round cell tumors requires immunohistochemical and ultrastructural techniques.