Background: Orbital and ocular metastases from well differentiated neuroendocrine (carcinoid) tumors are rare. They can be the primary presentation of a carcinoid tumor or develop during the course of the disease. Patients with orbital metastases typically present with diplopia, proptosis, and decreased vision. This report reviews the clinical presentation and treatment outcome for seven patients with well differentiated gastrointestinal neuroendocrine tumors (NET) who have ocular or orbital metastasis.

Methods: This study is a retrospective chart review of seven cases obtained from a single institution after receiving institution board review approval. Patient data collected included demographics, pathology, type of therapy, and survival outcomes.

Results: Between 1990 and 2019, 7 well-differentiated metastatic NET patients with orbital (N=5) or ocular metastasis (N=2) were identified. Tumor primary sites included pancreas, small bowel and unknown. A decrease in vision was the first manifestation in 1 of the 7 patients. Five patients had an established diagnosis of NET prior to developing ophthalmic symptoms and 1 patient had asymptomatic ocular metastasis. Staging MRI did not show any associated brain or leptomeningeal disease. Radiation therapy was delivered in 3 patients, one of which underwent surgery prior to radiation, and 1 patient received peptide radionuclide receptor therapy (PRRT). The other 3 patients were on surveillance with frequent ophthalmology exams. Three patients had expired. Two of the patients had next generation sequencing; 1 with ATM and CDKN1B genomic alterations and 1 with no alterations.

Conclusion: All seven patients with orbital or ocular metastasis from NET had evidence of other systemic metastases. Orbital and ocular disease was stable with no evidence of deterioration of vision.