title: False-positive iodine-131 whole-body scans due to cholecystitis and sebaceous cyst.
abstract: False-positive whole-body 131I scans are not frequent but have serious consequences in the management of patients with thyroid cancer. They can be classified in four main groups: elimination of iodine in body fluids, infection or inflammation, cysts or transudates and nonthyroid tumors. We report on two patients with false-positive post-therapy 131I scans. The first patient had uptake projected in the right pelvic area which was later proven to be a large gluteal sebaceous cyst. The second patient had uptake in the gallbladder area that did not disappear after 131I treatment; she underwent exploratory laparotomy which revealed extensive chronic cholecystitis. These cases illustrate two new causes of false-positive 131I whole-body scans (sebaceous cyst and cholecystitis), which highlights two mechanisms (elimination in body fluid and inflammation).
authors.affiliation: Molecular and Cellular Endocrinology Branch, National Institute of Diabetes and Digestive and Kidney Disease, National Institutes of Health (NIH), Bethesda, MD 20892-1770, USA.
authors.forename: F
authors.initials: F
authors.lastname: Brucker-Davis
authors.forename: J C
authors.initials: JC
authors.lastname: Reynolds
authors.forename: M C
authors.initials: MC
authors.lastname: Skarulis
authors.forename: D L
authors.initials: DL
authors.lastname: Fraker
authors.forename: H R
authors.initials: HR
authors.lastname: Alexander
authors.forename: B D
authors.initials: BD
authors.lastname: Weintraub
authors.forename: J
authors.initials: J
authors.lastname: Robbins
mesh_terms: D018263:Adenocarcinoma, Follicular / Q000000981:diagnostic imaging / Q000556:secondary*; D002291:Carcinoma, Papillary / Q000000981:diagnostic imaging / Q000556:secondary*; D002764:Cholecystitis / Q000000981:diagnostic imaging*; D004814:Epidermal Cyst / Q000000981:diagnostic imaging*; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes; D008297:Male; D008875:Middle Aged; D011877:Radionuclide Imaging; D013964:Thyroid Neoplasms / Q000473:pathology* / Q000601:surgery; D013965:Thyroidectomy
chemical_list: D007457:Iodine Radioisotopes