Radioiodine avid benign polyp in a post-treatment whole body 131I scan

Background: A 47-year-old lady with papillary thyroid carcinoma underwent total thyroidectomy accompanied with a course of radioiodine (131I) ablation about 2 years ago. During the disease follow up, the patient presented with rising thyroglobulin levels and re-treated with 131I. Seven days later she was referred to our department for whole body iodine scan.Methods: The whole body radioiodine scan was performed in anterior and posterior views. We also acquired lateral and delayed (24 hours after the whole body images) static images for precise evaluating the suspicious focus of radiotracer uptake.Results: The whole body images revealed focal intense radioiodine uptake in the right lower quadrant of the abdomen. The previous post-ablation SPECT/CT scan performed after the first course of radioiodine ablation also showed similar focal 131I uptake in the same region.Conclusion: We observed a fix radioiodine uptake in the right lower quadrant of the abdomen compatible with the right colon site in two consecutive whole body iodine scans with an interval of about 1 year. Endoscopic evaluation of the large intestine detected a pedunculated polyp in the right colon. Eventually, a benign adenomatous polyp was confirmed by histopathologic assessment. In accordance with the literature, radioiodine avidity is not specific for thyroid gland tissue and a considerable number of physiologic and pathologic 131I uptakes have been reported hitherto.

کلیدواژه ها:

Colonic polyp ، 131I uptake ، whole body iodine scan