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 2 is a 68-year-old male who was initially diagnosed with a well-differentiated G2 (Ki-67 10%) metastatic ileal NET in 2012. Post-resection of his primary, the patient began treatment with octreotide. Eventually, he enrolled on a clinical trial with 177Lu-DOTATATE PRRT. During a hospitalization in November 2017, while admitted for abdominal pain, he developed left peri-orbital swelling. This prompted an orbital MRI which demonstrated bilateral extraocular masses in his recti muscles (Fig. a). A subsequent biopsy confirmed metastatic NET. To manage his acute periorbital swelling, he was first treated with corticosteroids and later completed image-guided radiation therapy (IGRT) to 44 Gy to bilateral orbits in December 2017. The patient had a post-treatment MRI scan which demonstrated a decrease in signal abnormality and enhancement in the previously visualized lesions (Fig. b). Post-radiation, patient continued octreotide until his death in February 2018 due to progressive disease.