Orbital Radioiodine Uptake in Epithelial Conjunctival Inclusion Cyst on Scintigraphy in a Patient With Differentiated Thyroid Cancer

Abnormal focal accumulation of 131 I is generally a reliable indicator of differentiated thyroid cancer metastases. However, many examples of false-positive 131 I uptake were reported but only a few with orbital accumulation of radioiodine. We report the case of a 68-year-old woman with differentiated thyroid cancer who underwent thyroid remnants ablation with radioiodine. A focus of considerable 131 I uptake corresponding to a small, periorbital tumor was detected on posttherapy whole-body 131 I scan and head SPECT/CT. The tumor was surgically removed, and pathology revealed a conjunctival inclusion cyst with no features of thyroid tissue. Orbital 131 I uptake was not detected on follow-up scans.