Multiple Metastatic Lesions on a Post-Ablative Whole-Body Scan Despite a Negative Serum Thyroglobulin Level in a Patient With Papillary Thyroid Cancer
Abstract
Serum thyroglobulin (Tg) and radioactive iodine (RAI) whole-body scan (WBS) have been used to detect recurrent and metastatic differentiated thyroid cancer after total thyroidectomy and RAI remnant ablation. Discordant results of serum Tg and WBS are occasionally encountered, and a negative serum Tg and positive WBS are less common than a positive serum Tg and negative WBS. The author reports a rare case of a 41-year-old man with papillary thyroid cancer who showed unsuspected multiple metastatic lesions in both cervical lymph nodes and both lungs on post-ablative WBS despite a negative stimulated serum Tg level after total thyroidectomy and that an initial negative stimulated serum Tg level was converted to positive after RAI remnant ablation. In conclusion, RAI WBS can contribute to the detection of a relatively small number of unsuspected local and distant metastases despite a negative stimulated serum Tg.
J Endocrinol Metab. 2024;14(2):78-84
doi: https://doi.org/10.14740/jem940