Incidental discovery of pulmonary metastases during I-131 scintigraphy after total thyroidectomy

We report the case of a 40-year-old man with radiographically silent pulmonary metastases of papillary thyroid cancer discovered during I-131 scintigraphy following total thyroidectomy performed 10 years after unilateral lobectomy. The residual lobe was histologically normal. After a dose of 11.1 GBq (300 mCi), there was no I-131 uptake in the thyroid bed and lung metastases, and serum thyroglobulin became undetectable. Conservative therapy could be associated with a delay in the possibility of diagnosing and treating extrathyroidal metastases.