Primary Neuroendocrine Tumor of the Orbit Presenting with Acute Proptosis

: Primary neuroendocrine tumors of the orbit are exceedingly rare and typically present with gradual, progressive exophthalmos. In this report, an otherwise healthy 64-year-old woman undergoes resection of a well-differentiated neuroendocrine tumor after presenting with acute proptosis. An extensive clinical and radiographic evaluation reveals no other evidence of disease, establishing the diagnosis of a primary neuroendocrine tumor. The case presentation is followed by a brief review of the classification, presentation, and evaluation of orbital neuroendocrine tumors.