A case series of neuroendocrine (carcinoid) tumor metastasis to the orbit

To report the clinical and radiographic features and treatment outcome of neuroendocrine tumor (carcinoid) metastasis to the orbit.

Retrospective chart review of four cases.

Mean patient age at the time of diagnosis of the primary neuroendocrine tumor and orbital metastasis was 58 and 66 years, respectively, with a mean duration of 8 years between diagnosis of primary tumor and orbital metastasis. Primary neuroendocrine tumor sites were gastrointestinal tract (n = 2), lung (n = 1), and testicle (n = 1). The most common presenting symptom was diplopia (three cases). Magnetic resonance imaging revealed orbital tumor in all cases. Octreotide scan was positive in one case. Treatment was tumor excision in three cases followed by external beam radiotherapy in two cases and one patient was followed without treatment. Tumor cells showed immunoreactivity to chromogranin, synaptophysin, and neuron-specific enolase in all cases. Mean follow-up after orbital tumor diagnosis was 39 months. Three patients had known systemic extraorbital metastasis before orbital involvement (mean interval of 5.9 years) and one case had immediately after development of orbital metastasis. One patient had multiple recurrences of orbital metastasis and eventually underwent exenteration. Two patients died of disseminated metastasis between 2 and 3 years after diagnosis of orbital metastasis.

All four patients with orbital metastasis from neuroendocine tumor had evidence of systemic extraorbital metastasis. Aggressive metastatic neuroendocine tumors of orbit can lead to local recurrence even after surgical excision and radiation. Imaging tests were helpful in allowing early diagnosis and for monitoring after treatment.