# Thyrotroph pituitary neuroendocrine tumour (TSH-secreting)

Source: https://onco.cc/cancers/thyrotroph-pitnet/  
OnCo record `thyrotroph-pitnet` (Cancer). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

A thyrotroph tumour is a very rare pituitary tumour that secretes TSH, driving the thyroid to overactivity with a TSH level that is not suppressed. It is often mistaken for common hyperthyroidism and wrongly treated by destroying the thyroid, which makes the pituitary tumour grow. Surgery is the treatment of choice; somatostatin analogues control most of the rest.

## Summary

The 2022 WHO classification places the thyrotroph tumour in the PIT1 lineage, defined by TSH-beta and GATA3 staining (Asa 2022). The European Thyroid Association guideline notes that TSH-secreting tumours are characterised by high free thyroid hormones with non-suppressed TSH, that failure to recognise them may lead to inappropriate thyroid ablation with a significant increase in pituitary tumour mass, that diagnosis rests on TSH response to T3 suppression and TRH stimulation together with imaging and genetic testing to exclude thyroid hormone resistance, and that surgery is the treatment of choice with somatostatin analogues normalising TSH in most surgical failures (ETA 2013). In 90 consecutive patients operated on between 1991 and 2013 (47 women, median age 42, range 11 to 74), 18 percent were microadenomas and 82 percent macroadenomas, microadenomas becoming more frequent recently, 23 percent invaded the cavernous sinus, 74 percent were firm or hard, and co-secretion of growth hormone or prolactin occurred (J Neurosurg 2014).

How it differs from its parent: its syndrome mimics Graves disease, so the diagnostic trap is thyroid rather than pituitary; the tumours are often fibrous and invasive, making complete resection harder; and somatostatin analogues are unusually effective medically.

How common: no incidence figure in the sources read; the rarest functioning pituitary tumour (ETA 2013).

Treatment: transsphenoidal surgery after rendering the patient euthyroid; somatostatin analogues (octreotide, lanreotide) for residual or recurrent disease; radiotherapy where medical control fails (ETA 2013; J Neurosurg 2014).

## Fields

- Kind: Cancer
- Last checked: 2026-09-24
- Also known as: Thyrotroph tumour; TSHoma; Thyrotropin-secreting pituitary adenoma; TSH-secreting pituitary tumour; Thyrotroph adenoma
- Tags: subtype-page; wave4; rare
- Group: endocrine
- Burden: The rarest functioning pituitary tumour and a very rare cause of hyperthyroidism (ETA 2013); the largest surgical series holds 90 patients, median age 42, 82 percent macroadenomas (J Neurosurg 2014). GLOBOCAN does not count pituitary tumours.
- Subtypes: Thyrotroph pituitary macroadenoma (82 percent; often invasive and fibrous); Thyrotroph pituitary microadenoma (increasingly recognised); Thyrotroph tumour co-secreting growth hormone or prolactin (PIT1 lineage plurihormonal)
- Biomarkers: Free T4 and T3 with non-suppressed TSH; TSH response to T3 suppression and TRH stimulation; alpha-subunit; TSH-beta, GATA3 and PIT1 immunostaining; Thyroid hormone receptor beta testing to exclude resistance

## Sections of this record

The page is a hub with ten sections in reading order; large sections have their own page. The same plan as JSON: https://onco.cc/api/v1/cancers/thyrotroph-pitnet/sections.json

- Overview (on the hub): The TL;DR, the family this cancer belongs to, the organ, who gets it and what the state of the art is. https://onco.cc/cancers/thyrotroph-pitnet/#overview
- What it is (on the hub): Anatomy, the subtypes and how they differ, how it is staged, and where advanced disease spreads. https://onco.cc/cancers/thyrotroph-pitnet/#what-it-is [3 subtypes]
- Finding it (on the hub): How it shows itself, how it is confirmed, what screening exists, and the biomarkers clinicians test for. https://onco.cc/cancers/thyrotroph-pitnet/#finding-it [4 biomarkers]
- Treating it (on the hub): The standard of care by setting, the medicines, surgery and radiotherapy named in it, and the regimens behind them. https://onco.cc/cancers/thyrotroph-pitnet/#treating-it [1 setting, 1 decision with options]
- Evidence (on the hub): Trials recruiting now, the landmark trials, the key papers and what they mean, the latest literature, and the milestones year by year. https://onco.cc/cancers/thyrotroph-pitnet/#evidence
- The science (on the hub): The molecular landscape: the targets and how often each appears, the pathways, the mechanics stages and the preclinical models. https://onco.cc/cancers/thyrotroph-pitnet/#science [1 target]
- Where you are (own page): Cases by country, the UK and NHS pathway and other country lenses, and the expert centres with trials on record. https://onco.cc/cancers/thyrotroph-pitnet/where-you-are/
- Living with it (on the hub): The decisions you may face, the aids that walk through them, the warnings on record, the first sixty days and the questions to ask. https://onco.cc/cancers/thyrotroph-pitnet/#living-with-it [8 questions]
- What is coming (own page): Everything in development, the open problems and what is being done about them, the roadmaps, and what changed on this record. https://onco.cc/cancers/thyrotroph-pitnet/coming/ [1 medicine]
- Data (own page): Every connected record, the notes, the JSON, Markdown and RDF twins, and where the record came from and when it was checked. https://onco.cc/cancers/thyrotroph-pitnet/data/ [4 connected records]

## Standard of care

- All cases: Transsphenoidal surgery after achieving euthyroidism; somatostatin analogues for residual disease; radiotherapy where medical control fails (ETA 2013). ([Pituitary tumours (pituitary neuroendocrine tumours) and pituitary carcinoma](https://onco.cc/cancers/pituitary-tumours/), [Pasireotide](https://onco.cc/drugs/pasireotide/), [Stereotactic radiosurgery (Gamma Knife, CyberKnife, linac SRS)](https://onco.cc/technologies/radiosurgery-srs/))

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/Thyrotropic_pituitary_adenoma
- NCI PDQ: pituitary tumours treatment: https://www.cancer.gov/types/pituitary/treatment
- Asa 2022, Endocrine Pathology: overview of the 2022 WHO classification of pituitary tumours: https://doi.org/10.1007/s12022-022-09703-7
- European Thyroid Journal 2013: ETA guidelines for thyrotropin-secreting pituitary tumours: https://doi.org/10.1159/000351007
- J Neurosurg 2014: thyrotropin-secreting pituitary adenomas, 90 cases treated by transsphenoidal surgery: https://doi.org/10.3171/2014.7.jns1471

## Connected records

- cancers: [Gonadotroph pituitary neuroendocrine tumour (non-functioning adenoma)](https://onco.cc/cancers/gonadotroph-pitnet/), [Lactotroph pituitary neuroendocrine tumour (prolactinoma)](https://onco.cc/cancers/lactotroph-pitnet/), [Pituitary tumours (pituitary neuroendocrine tumours) and pituitary carcinoma](https://onco.cc/cancers/pituitary-tumours/), [Somatotroph pituitary neuroendocrine tumour (acromegaly)](https://onco.cc/cancers/somatotroph-pitnet/), [Thyroid cancer](https://onco.cc/cancers/thyroid/)
- technologies: [Stereotactic radiosurgery (Gamma Knife, CyberKnife, linac SRS)](https://onco.cc/technologies/radiosurgery-srs/)
- drugs: [Pasireotide](https://onco.cc/drugs/pasireotide/)

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JSON: https://onco.cc/api/v1/entities/thyrotroph-pitnet.json