title: False-Positive Radioactive Iodine Uptake Mimicking Miliary Lung Metastases in a Patient Affected by Papillary Thyroid Cancer and IgA Deficiency.
abstract: A 42-year-old female with immunoglobulin A deficiency and recurrent sinopulmonary infections underwent thyroidectomy for papillary thyroid cancer (PTC). Follow-up (123)I scintigraphy demonstrated diffuse pulmonary uptake, suggesting metastatic disease. However, subsequent pathologic, biochemical and radiographic testing proved that she was in fact disease free, and the initial (123)I pulmonary uptake was identified as a false positive. Inflammatory conditions may rarely cause iodine uptake in non-thyroidal tissues due to local retention, organification, and/or immunologic utilization. To avoid exposing patients to unnecessary treatments, it is critical for clinicians to recognize that comorbid pulmonary conditions may mimic metastatic PTC on radioiodine scintigraphy.
authors.affiliation: Section on Growth and Obesity, Program in Developmental Endocrinology and Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, 9000 Rockville Pk, Building 10/1-3330, Bethesda, MD 20892-1613 USA.
authors.forename: Andrew Paul
authors.initials: AP
authors.lastname: Demidowich
authors.affiliation: Department of Medicine, University of Massachusetts Medical School, Worcester, MA USA.
authors.forename: Amartya
authors.initials: A
authors.lastname: Kundu
authors.affiliation: Nuclear Medicine Division, Radiology and Imaging Sciences Department, Clinical Center, National Institutes of Health, Bethesda, MD USA.
authors.forename: James C
authors.initials: JC
authors.lastname: Reynolds
authors.affiliation: Division of Endocrinology and Metabolism, Virginia Commonwealth University, Richmond, VA USA.
authors.forename: Francesco S
authors.initials: FS
authors.lastname: Celi
keywords: False-positive reactions; IgA deficiency; Papillary thyroid carcinoma; Radionuclide imaging; Scintigraphy