Thyroid-Stimulating Hormone (TSH)-Secretory Macroadenoma Presenting with Recurrent Atrial Fibrillation in Failure
https://doi.org/10.15605/jafes.041.S1
- Author:
Muzhaffar Mokhtar
1
;
Masliza Hanuni Mohd Ali
1
;
Wan Mohd Hafez Wan Hamzah
1
Author Information
1. Endocrine Unit, Department of Medicine, Hospital Sultanah Nur Zahirah
- Publication Type:Journal Article
- MeSH:
Atrial Fibrillation;
Thyrotropin
- From:
Journal of the ASEAN Federation of Endocrine Societies
2026;41(S1):95-96
- CountryPhilippines
- Language:English
-
Abstract:
Introduction:Accounting for less than 2% of all pituitary adenomas, TSHsecreting pituitary adenomas (TSHoma) are an uncommon
cause of hyperthyroidism. Majority are macroadenomas
with delayed diagnosis as most patients are unwittingly
treated for primary hyperthyroidism. Recurring discordant
thyroid function test (TFT) with elevated thyroidstimulating hormone (TSH) and Free T4 is a hint and
warrants additional investigation to facilitate diagnosis.
Case:We report a case of a 48-year-old female who was treated
for primary hyperthyroidism since her late 20s with
multiple admissions for recurrent congestive heart failure and atrial fibrillation. The cardiac issue was preceded by
worsening thyrotoxicosis. Previous thyroid autoantibodies
were negative. Of note, she had recurring discordant
TFT results from two different assays (TSH:84.7, free
thyroxine 4 [FT4]:75.43) (TSH:37.86, FT4:27.34) during
admission, excluding assay interference and prompting
toward TSHoma or Resistance to Thyroid Hormone (RTH).
Examination revealed a large goiter (10 × 8 cm) hard in
consistency, and pansystolic murmur over tricuspid area.
No thyroid eye disease nor bitemporal hemianopia or
clinical sign of acromegaly.
Echocardiography showed dilated left atrium and mild
to moderate tricuspid regurgitation with preserved
ejection fraction. Thyroid-releasing hormone (TRH)
stimulation test demonstrated blunted TSH response
confirming TSHoma. Anterior pituitary hormone profile
revealed normal insulin-like growth factor-1 level with
suppressed sex hormones and prolactin, thus excluding
co-secreting hormone. Sex hormone-binding globulin
level, α-subunit, and T3 suppression test were not done
due to unavailability. Magnetic resonance imaging
pituitary uncovered pituitary mass measuring (2.6 × 3.3 ×
2.2 cm) suggestive of macroadenoma with encasement of
cavernous internal carotid arteries and cavernous sinus
compression. Computed tomography neck revealed diffuse
thyroid enlargement with compressive mass effects onto
adjacent structure with trachea narrowing. After discussing
with a multidisciplinary team, we planned her for total
thyroidectomy followed by transsphenoidal surgery.
Conclusion:Late presentation and diagnosis in TSHoma remain a
major challenge. TFT interpretation is fundamental in
identifying the causes of secondary hyperthyroidism to
avert detrimental sequalae and to guide optimal treatment.
- Full text:2026080416023604483EP_A137.pdf
