Endocrine Abstracts

Carcinoid tumours are low grade neoplasms usually arising from neuroendocrine cells of the bronchial and gastrointestinal tracts. Carcinoid tumours metastasise in 50–75% of patients, most commonly to lymph nodes, liver, and bones, but intra-orbital metastases have only rarely been reported. Here, we describe a patient who presented with an intra-orbital neuroendocrine tumour which was successfully treated with surgery and radiotherapy. A 70-year-old female patient presented with diplopia and was found to have a right orbital tumour which was excised by craniotomy. Surprisingly, the histology revealed a neuroendocrine tumour of small bowel origin. Subsequent imaging identified a small bowel primary tumour for which she underwent surgical removal. The histological diagnosis was a grade 1 neuroendocrine tumour (Ki-67 proliferation index of 2%) with 6/14 lymph nodes involved and extra-nodal spread and the histological features matched those of the orbit. Further disease recurrence in the bowel necessitated repeat bowel surgery and ileocaecal tumour resection. Follow-up Gallium-68 DOTATATE PET scanning showed a DOTATATE-avid recurrence of her orbital diseases more than 5 years after her original surgery. She underwent successful Gamma Knife radiosurgery and remains free from recurrence 12 months later. Neuroendocrine metastases to the orbit are extremely rare, but can have a significant impact on patients’ quality of life. Treatment options for orbital neuroendocrine tumour metastases include surgical excision, orbital exenteration, radiotherapy, as well as chemotherapy. As demonstrated in this case, metastatic neuroendocine tumours of the orbit can lead to local recurrence many years after surgical excision and/or radiotherapy. Therefore, longterm surveillance imaging is mandatory to allow early detection of recurrent disease.