Introduction: Here we present our experience of managing patients with orbital well-differentiated neuroendocrine tumour (NET) metastases.
Methods: Six patients were identified from the hospital NET database: four male; two female.
Results: Median age at diagnosis of primary NET: 69.5 years (range: 40-74 years). Three patients were alive at time of data capture. Of those who passed away: mean survival from diagnosis of primary NET = 326 weeks (range 135-447 weeks); mean survival from diagnosis of ocular metastases = 168 weeks (range: 39-408 weeks). Four patients had GI primary NET; one lung; one thymus. Median time between diagnosis of primary and ocular metastases: 68 weeks (range: 6-338 weeks). Ki67 at time of primary diagnosis: 4 patients were </=1%; 2 patients </=5%. Median 5-HIAA at time of primary diagnosis: 119.3 (range 20-334.3). Median 5-HIAA at time of ocular metastases: 108.1 (range 12-363). Additional to orbital metastases: 3/6 had liver metastases; 1/6 pancreas; 1/6 breast; 1/6 bone; 3/6 nodal disease. One patient had intracranial involvement. In five patients, the primary was identified first. Three patients were investigated on the basis of ocular symptoms, and diagnosed on the basis of histology. Those with eye symptoms: 2/6 patients suffered binocular diplopia; 2/6 patients ophthalmoplegia; 2/6 patients unilateral proptosis. The remaining patients were identified incidentally on the basis of Octreotide-Scan or DOTA-PET Scan. Two patients had prior ocular history separate from their metastatic disease: both had a diagnosis of glaucoma; one had bilateral early cataracts. Orbital involvement: 3/6 right orbital involvement; 1/6 left orbital; 2/6 both orbits. Superior rectus involved in 1/6; medial 2/6; inferior 2/6; lateral 3/6. 4/6 had rectus involvement; 3/6 had extra-global involvement. In terms of treatment: one patient received orbital radiotherapy. Two patients were provided spectacles with an occluded lens for symptomatic relief of diplopia. 4/6 patients had follow-up imaging of their ocular metastases. Median time from first orbital imaging to last follow-up imaging: 220 weeks (range: 68-331 weeks). Progression on follow-up imaging: one stable; two marginal increase; one progressed along anterior cranial fossa.
Conclusion: Orbital involvement by NETs is rare and thankfully does not require radical treatments.