Pattan V, Mehra I, Khan SA, Kashyap R. Atypical Thyroid Function Tests and Thyroid Hormone Resistance.
Cureus 2021;
13:e16328. [PMID:
34306893 PMCID:
PMC8279904 DOI:
10.7759/cureus.16328]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/12/2021] [Indexed: 12/05/2022] Open
Abstract
Clinical interpretation of thyroid labs is usually straightforward. However, there are rare instances when the atypical profile of thyroid labs warrants systematic investigation to determine the underlying cause. We report the case of a 90-year-old Caucasian male with a chronic history of atrial fibrillation with chronic pacemaker dependence who presented with significantly elevated free thyroxine level (>7.77 ng/dL) but normal thyroid-stimulating hormone level (2.15 µIU/mL). After ruling out pituitary tumors and artifactual errors due to lab interference, the diagnosis of thyroid hormone resistance was made.
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