Orbital metastasis from neuroendocrine tumour: Case report and literature review

Orbital metastases from neuroendocrine tumour are rare entities. An incidental finding of orbital metastasis originating from neuroendocrine tumour is presented in the context of a comprehensive review of all case reports and series published to date. Demographics, clinical features, diagnostic work-up, treatment and prognostic data from the published literature are discussed. Ninety-five patients with orbital metastases from neuroendocrine tumours have been reported so far. Average age at presentation is 63.8 years (range 25-86), with no significant gender predominance. Gastrointestinal tract is the most common site of primary neuroendocrine tumours (62-85%). Typical presentation includes proptosis (80-85%) and diplopia (27-62%) in patients with known primary neuroendocrine tumour elsewhere. Histological subtype and presence of metastases seem to be important prognostic factors. Incidental finding of neuroendocrine tumour mestastases in asymptomatic patients with unknown primary disease is uncommon. In such cases, orbital biopsy and structural and functional imaging are essential to establish a diagnosis and stage the disease.

Orbital plasmacytoma as the presenting feature in multiple myeloma

A 50-year-old female patient presented with protrusion of the left eye for 1 month. Examination showed abaxial proptosis, restriction of extraocular movements, and elevated intraocular pressure. Computed tomography of the orbits showed soft tissue enhancing lesion in the superolateral aspect of the left orbit with lytic lesions in calvarium. Fine needle aspiration cytology of the lesion revealed a diagnosis of plasmacytoma with positive CD138 and CD38 immunohistochemical stains. Erythrocyte sedimentation rate, C-reactive protein and serum lactate dehydrogenase were elevated. Serum protein electrophoresis revealed hypergammaglobulinemia, and bone marrow biopsy revealed 6% plasma cells. The patient was started on chemotherapy with bortezomib, dexamethasone and lenalidomide by the medical oncologist. Significant improvement in proptosis and extraocular movements noted on follow-up. Orbital myeloma may be the first manifestation of systemic disease.