Incidental detection of acquired unilateral nasolacrimal duct obstruction on I-131 whole body scan following I-131 therapy for thyroid cancer: a case report

Abstract Background Radioactive iodine 131 (I-131) is used in the treatment of differentiated thyroid cancer after thyroidectomy; however, its accumulation non-thyroidal regions may give false positive results on whole body scan (WBS). Only a few cases radioiodine uptake orbital region patients with have been reported, which could be due to metastasis or causes resulting from contamination inflammatory etiology. Case presentation We describe case 49-year-old male history papillary carcinoma. The follow-up I-131 showed focus increased radiotracer left orbit. Correlative single photon emission computed tomography (SPECT-CT) that was stenosis nasolacrimal duct causing obstructive symptoms side. Dacryoscintigraphy also demonstrated significant obstruction system. Conclusions rare adverse event therapy can result an scan, mimicking metastasis. use additional spot views and SPECT-CT images along thyroglobulin levels help physicians clarifying situation these uncertain cases.