False-positive radioactive iodine uptake in a large uterine fibroid

Incidental findings in the post-treatment whole body iodine scan (WBIS) sometimes have a broad list of differentials. We present a case of differentiated thyroid carcinoma (DTC), pT۳aN۱b, with family history of DTC. She was treated with adjuvant ۱۳۱I therapy (۵.۵۵ GBq). The patient's post-treatment WBIS revealed a large, round iodine-avid area above the bladder, which was attributed to a massive uterine fibroid. Physical examination as well as radiologic correlation with SPECT/CT were also concordant. Fibroids can trap the radioiodine by various mechanisms. This case serves as a reminder of an uncommon pitfall in WBIS, particularly in women of reproductive age.

Keywords:

Whole-body iodine scan , Pitfalls , False-positive , Uterine fibroid , Iodine-۱۳۱