False-Positive Radioiodine Uptake Related to Posttraumatic Scab Demonstrated by SPECT/CT in a Patient With Differentiated Thyroid Cancer

A 20-year-old man with papillary thyroid cancer received a fourth radioiodine regimen to treat 131I-avid lung metastases. Posttherapeutic whole-body scan revealed focal radioiodine uptake on the anterior region of the left lower limb that was not visible on previous whole-body scan and which suggested skin contamination. Visual examination of the left leg evidenced a posttraumatic scab caused by a fall 2 weeks before. Skin metastasis was ruled out. 131I SPECT/CT acquisition ruled out bony uptake and confirmed that the skin uptake was related to the superficial scab.