131I whole-body scan is performed during treatment and follow-up after radioiodine treatment to detect functioning thyroid remnant and metastatic lesions in differentiated thyroid carcinoma (DTC). False-positive scans are rare, but may cause a potential pitfall by misleading to unnecessary radiation exposure from inappropriate radioiodine treatment. We report a case of papillary thyroid cancer patient with false-positive 131I scan in the lung due to pulmonary bronchiolitis. Clinical correlation and imaging characteristics obtained from additional SPECT/CT images are very helpful to indicate this lesion as a benign condition.
From the Division of Nuclear Medicine, Department of Radiology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand.
Received for publication September 4, 2012; and revision accepted December 29, 2012.
Conflicts of interest and sources of funding: none declared.
Reprints: Tanyaluck Thientunyakit, MD, Division of Nuclear Medicine, Department of Radiology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand. E-mail: firstname.lastname@example.org.