Orbital metastasis diagnosed by ultrasound-guided fine-needle aspiration biopsy: Case report of unknown primary site.

Twenty five percent of orbital metastasis is usually of unknown primary origin and it requires histopathological and immunohistochemical confirmation. The fine-needle aspiration biopsy (FNAB) of the orbit is an alternative procedure to conventional orbitotomy. The case is presented of a 60 year-old woman with a right orbit tumour mass and neoplastic lesions in her brain and cranium. As an incidental finding, she had a thrombus in her left atrium, and so an orbitotomy procedure was ruled out. An ultrasound-guided FNAB was performed instead with rapid on-site evaluation (ROSE) of biopsy samples. These showed malignant cells of a lung adenocarcinoma, which was confirmed with immunohistochemistry and chest diagnostic images. In conclusion, biopsy samples obtained by FNAB, together with cytopathological and immunohistological analysis, enabled orbital metastasis to be identified in the case described, and showed that FNAB is a safe, effective, and minimally invasive alternative.