An unusual 131I-avid adrenal metastasis from follicular thyroid carcinoma identified by 131I-SPECT/CT.

The adrenal gland is an uncommon site of metastasis from differentiated thyroid carcinoma, and I-avid adrenal metastatic lesions are even rarer. Here, we describe a 54-year-old woman with I-avid adrenal metastasis from follicular thyroid carcinoma identified using I whole-body scan (I-WBS) and I-SPECT/CT. I-SPECT/CT allowed superior localization of the equivocal I uptake in the I-WBS. It provides metabolic and anatomic information about a lesion, resulting in accurate localization and improved definition of I-WBS findings.