Patient 1 is a 72-year-old female who was initially diagnosed in 1997 with a well differentiated G3 (Ki-67 20%) metastatic jejunal NET. Her primary tumor was resected after diagnosis and a liver transplant was performed in 1998 for bulky symptomatic liver metastases. She has received a series of therapies including octreotide, lanreotide, and everolimus for her carcinoid syndrome (CS) and disease control. In May 2017, a 68Ga-DOTATATE PET-CT revealed somatostatin receptor (SSTR) avidity in bilateral orbits although she was asymptomatic from a visual symptom standpoint (Fig. a and b). In March 2018, the patient was hospitalized for preseptal cellulitis. During the hospitalization, she underwent a CT scan which revealed focal thickening of the right medial rectus and left lateral rectus muscles. Opthalmology evaluated her and felt the cellulitis was unrelated to her orbital masses. Once her infection resolved she underwent biopsy of a rectus muscles mass which confirmed orbital metastases from her NET primary. Patient did not have any worsening visual symptoms or signs (limited extraocular motility, visual field deficits or proptosis).\n177Lu-DOTATATE PRRT was initially recommended; however, this was not pursued due to the patient’s poor renal function. Radiation therapy was then considered but given the proximity of the lesions to other critical structures and her lack of symptoms, this too was deferred in favor of close surveillance. In July 2018, she started on capecitabine and temozolomide for better systemic control of her NET, which also involved her liver, pancreas, bone and intra-abdominal lymph nodes. On a follow-up orbital MRI in July 2018, her lesions were noted to be stable.
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 [].