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.