Neuroendocrine tumor metastatic to the orbit treated with radiotherapy

Abstract

Neuroendocrine tumors are rare neoplasms that infrequently metastasize to the orbit. Given that patients with these tumors may have prolonged survival despite dissemination, maintaining quality of life by providing early diagnosis and effective treatment to preserve vision and comfort is a fundamental issue. We report the case of a 79-year old woman who presented with well-differentiated metastatic neuroendocrine tumor to the liver with no carcinoid syndrome and was started on intramuscular long-acting octreotide with disease stabilization. Two years later she developed right-sided diplopia associated with mild eye discomfort, proptosis and reddening. An magnetic resonance imaging showed a 2.1 cm mass in the right orbit and further biopsy confirmed a neuroendocrine tumor metastasis. The patient was treated with a four-week course of stereotactic radiotherapy to the right orbital metastasis (4000 cGy in 20 fractions) with minor conjunctivitis as the only side effect. Eighteen months later, she remains well with no visual loss.

Keywords: Neuroendocrine tumor, Carcinoid tumor, Orbital metastases, Diplopia, Radiotherapy

Core tip: Neuroendocrine tumors are rare neoplasms that only uncommonly metastasize to the orbit. Given these tumors are associated with prolonged survival despite dissemination, maintaining quality of life by providing early diagnosis and effective treatment to preserve vision and comfort is a fundamental issue. We report the case of a patient who 2 years after the diagnosis of metastaic neuroendocrine tumor to the liver presented with right-sided diplopia. She was found to have metastatic neuroendocrine tumor to the right orbit and was successfully treated with radiotherapy. Eighteen months later, she remains well and with no visual loss.