ABSTRACT

The role of radioiodine-131(I-131) Whole- body scan (WBS) is crucial regarding the management of patients with differentiated thyroid carcinoma (DTC) in detecting normal thyroid remnants and recurrent or metastatic disease. Although I-131 is a sensitive marker for detection of thyroid cancer, radioiodine uptake is not specific for thyroid tissue. According to several reports, various tissues or non-thyroidal pathologic processes were associated with falsepositive WBS with radioiodine. In this case report we reported that the false positive result was present due to the fistula accompanied by the suture granuloma. A 47 year-old woman underwent total thyroidectomy for papillary thyroid carcinoma.A false-positive iodine uptake in the midline neck was determined by a diagnostic I-131 whole body scan. I-131 whole body scan was correlated with ultrasonography (US) and computed tomography (CT) imaging features, biochemical data, clinical history, and physical examination. The lesion was demonstrated to be a fistula tract accompanied by the suture granuloma. The false- positive findings in the I-131 whole-body scan should be confirmed with other imaging modalities, available biochemical data, clinical history, and physical examination in order to avoid unnecessary treatments.