A 63-year-old man presented with diplopia, redness, and pain of his left eye of 4 weeks duration. He had a history of neuroendocrine tumor of the testicle treated by radical orchiectomy 13 years before presentation followed by metastasis to the ileum, which was treated with bowel resection. Visual acuity was 20/30 OD and 20/25 OS and exophthalmometry revealed 4 mm proptosis of the left eye with mild limitation of ocular motility in lateral gaze. An intraconal, well-circumscribed mass in the left orbit displacing the lateral rectus muscle laterally was noted on MRI []. Histopathologic evaluation following tumor excision revealed a low-grade atypical neuroendocrine tumor with positive staining for chromogranin, synaptophysin, neuron-specific enolase, and AE1/3 compatible with carcinoid metastasis. Between the next 4.5 years, the patient had three recurrences of the orbital carcinoid which were managed with EBRT, surgical excision, and eventually orbital exenteration after the MRI showed early erosion of orbital bones by the tumor and tumor extension into the maxillary bone [Figures and ]. Histopathology of the exenterated orbital lesion showed multinucleated cells with large hyperchromatic nuclei and seven mitotic figures in 10 high-power fields consistent with aggressive metastatic poorly differentiated neuroendocrine tumor. The patient also developed signs of carcinoid syndrome with carcinoid metastasis to the liver, kidney, and parotid gland. He was alive with systemic metastasis 4 years after initial presentation.\nThe clinical and pathological features as well as treatment methods and outcomes for each patient are summarized in .
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.