False-Positive “Necklace Sign” on Whole-Body Thyroid Cancer Survey—A Case Report

Abstract

A woman with papillary thyroid carcinoma treated with surgery and postoperative ¹³¹I returned 4 y later for a whole-body survey. The imaging results initially suggested disease recurrence but were later found to be false positive and due to ¹³¹I uptake in a necklace that had been contaminated by the patient’s saliva. This case stresses the importance of having the patient remove all jewelry before undergoing a radioiodine survey.