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Resistance to Thyroid Hormone Beta Due to THRB Mutation in a Patient Misdiagnosed With TSH-Secreting Pituitary Adenoma.
- Source :
- JCEM Case Reports; Aug2024, Vol. 2 Issue 8, p1-6, 6p
- Publication Year :
- 2024
-
Abstract
- Elevated concentrations of T3 and T4 concomitant with nonsuppressed TSH are found in both TSH-producing tumors and resistance to thyroid hormone beta (RTHß), posing a diagnostic challenge. We demonstrate here a 54-year-old female who presented with palpitations, goiter, and elevated free T4 with nonsuppressed TSH concentrations (TSH 2.2 mIU/L [normal range, NR 0.27-4.2 mIU/L] and FT4 59.08 pmol/L [NR 12.0-22.0 pmol/L]). Because magnetic resonance imaging revealed a pituitary microadenoma (4 mm), she was diagnosed with TSH-secreting pituitary adenoma and underwent transsphenoidal surgery. Pathological reports showed no tumor cells. Subsequent genetic testing revealed a pathogenic variant in the THRB gene resulting in a His435Arg amino acid substitution in the T3 receptor isoform beta 1 (TRß1), suggestive of RTHß. In vitro and ex vivo studies revealed that the His435Arg mutated TRß1 (TRß1-H435R) completely abolishes the T3-induced transcriptional activation, nuclear receptor corepressor 1 release, steroid receptor coactivator 1 recruitment, and T3-induced thyroid hormone target gene expression, confirming the pathogenicity of this variant. The identification of a pituitary microadenoma in a patient with RTHß led to a misdiagnosis of a TSH-producing tumor and unnecessary surgery. Genetic testing proved pivotal for an accurate diagnosis, suggesting earlier consideration in similar clinical scenarios. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 27551520
- Volume :
- 2
- Issue :
- 8
- Database :
- Complementary Index
- Journal :
- JCEM Case Reports
- Publication Type :
- Academic Journal
- Accession number :
- 178989879
- Full Text :
- https://doi.org/10.1210/jcemcr/luae140