A 73-year-old woman presented with drooping of her right upper lid. Twelve years prior she had undergone resection of neuroendocrine tumor in the upper lobe of her right lung and a metastasis to the ninth thoracic vertebra, which was treated with EBRT. Subsequent 5-HIAA study and Indium-111 OctreoScan were within normal limits.\nVisual acuity was 20/20 OD and 20/40 OS. There was 1 mm proptosis and 3 mm blepharoptosis on the right side. MRI of the orbit revealed a heterogeneous lesion with contrast enhancement in the superior right orbit measuring 13 × 18 × 14 mm and a smaller lesion adjacent to the lacrimal gland []. Fine needle aspiration biopsy of the orbital tumor was consistent with neuroendocrine tumor with positive staining for chromogranin, AE1/AE3, synaptophysin, and CD56 but negative staining for CD45 consistent with atypical carcinoid. Excisional biopsy revealed a low-grade non-small cell neuroendocrine tumor. Residual orbital tumor was treated with EBRT. Within the next 2–6 years, she developed recurrent lesions in both lungs and multiple metastatic lesions in the thoracic vertebra, breast, scalp, and cavernous sinus which were treated with a combination of surgical excision, chemotherapy (carboplatin, etoposide, and paclitaxel), and EBRT. Six years after initial presentation, the patient was alive with no orbital tumor recurrence [].
Patient 5 is a 61-year-old female who was diagnosed with a well differentiated G2 (Ki-67 5%) metastatic small intestine (not otherwise specified) NET in February 2010. She remained symptom free until April 2014 when she was started on monthly octreotide. In the setting of progressive disease, she subsequently received sunitinib and everolimus. She began to develop progressive diplopia and right ocular pain in August 2016. This prompted an orbital MRI which revealed bilateral recti masses in the right lateral and superior left medial muscles. She was evaluated by radiation oncology shortly thereafter and was treated with IGRT to 52Gy, which completed in October 2016. Although her right ocular pain improved, she had persistent diplopia. Her post-treatment orbital MRI in January 2017 revealed a mild increase in size of her right lateral rectus mass (Fig. a). She was then started on capecitabine in January 2017 on a two week on, one week off regimen schedule. Patient also established care with ophthalmology at this time. She achieved stable disease in her orbits with symptomatic improvement and did not demonstrate any evidence of visual field deficits. She continues capecitabine and her last MRI in July 2018 revealed ongoing shrinkage of her right lateral rectus mass (Fig. b); her recent 68Ga-DOTATATE PET/CT from October 2018 shows residual SSTR avidity within her bilateral recti muscles (Fig. c and d).