False-Positive Iodine-131 Uptake Due to Wasp Sting.

A 38-year-old woman with papillary carcinoma of the thyroid who underwent total thyroidectomy followed by high-dose radioiodine ablation was called for Iodine-131 (I-131) whole-body follow-up scan. Her follow-up scan revealed focal tracer accumulation in the lower aspect of the right posterior neck region. Her stimulated serum thyroglobulin and anti-thyroglobulin antibodies were 0.27 ng/ml and undetectable, respectively. Further clinical examination of the patient revealed a black scab in the same region. The patient revealed a history of wasp bite 2 days before iodine administration.