The Study
Thyroid-Stimulating Hormone (TSH)-Secreting Pituitary Tumor Misdiagnosed for 20 Years: Possible Effect of Long-Term Treatment With Thyroid Hormone
This study is about one person who had a rare tumor and was given thyroid medicine for 20 years. It shows what happened to her, but it doesn't prove that the medicine caused the tumor to stay small. It's like seeing one rainbow and saying 'rainbows always appear after rain'—you need to see many to know for sure.
Analysis score
Maximum 30 for a case report.
Where the score came from
A woman was given high doses of thyroid hormone for 20 years because doctors thought her thyroid was underactive — but her thyroid was actually overactive because of a tiny brain tumor making too much TSH.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 530 / 100
Quality score
Snapshots of a population at a single point in time, or descriptions of small groups. Can identify correlations and prevalence, but cannot determine cause and effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1This is surprising because doctors thought such tumors always grow despite thyroid hormone treatment — but this one didn't, meaning some tumors might still listen to the body's signals.
- 2The tumor was 9–11 mm, stayed the same size for 20 years, and even shrank slightly after stopping the hormone pills and starting another drug (octreotide).
- 3Surgery removed it, and her thyroid levels returned to normal.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Related Content
Claims (5)
When thyroid hormone levels rise in the blood, the pituitary gland reduces its production of thyroid-stimulating hormone (TSH).
When thyroid hormone levels are high but the pituitary hormone TSH is not low as expected, this pattern indicates a TSH-secreting pituitary tumor.
Some TSH-secreting pituitary tumors stay small and do not spread beyond the pituitary gland for many years, unlike most large pituitary tumors that extend outside the gland.
In one case, a 65-year-old woman with a TSH-secreting pituitary tumor had no tumor growth for 20 years while taking high-dose levothyroxine, showing that some of these tumors can respond to thyroid hormone therapy.
Some TSH-secreting pituitary tumors do not shrink or change in size when treated with high doses of levothyroxine, indicating that these tumors vary in how they respond to thyroid hormone suppression.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.