{"entity":{"id":"thyrotroph-pitnet","kind":"cancer","name":"Thyrotroph pituitary neuroendocrine tumour (TSH-secreting)","aka":["Thyrotroph tumour","TSHoma","Thyrotropin-secreting pituitary adenoma","TSH-secreting pituitary tumour","Thyrotroph adenoma"],"tldr":"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).\n\nHow 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.\n\nHow common: no incidence figure in the sources read; the rarest functioning pituitary tumour (ETA 2013).\n\nTreatment: 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).","asOf":"2026-09-24","wikipedia":"https://en.wikipedia.org/wiki/Thyrotropic_pituitary_adenoma","links":[{"label":"NCI PDQ: pituitary tumours treatment","url":"https://www.cancer.gov/types/pituitary/treatment"},{"label":"Asa 2022, Endocrine Pathology: overview of the 2022 WHO classification of pituitary tumours","url":"https://doi.org/10.1007/s12022-022-09703-7"},{"label":"European Thyroid Journal 2013: ETA guidelines for thyrotropin-secreting pituitary tumours","url":"https://doi.org/10.1159/000351007"},{"label":"J Neurosurg 2014: thyrotropin-secreting pituitary adenomas, 90 cases treated by transsphenoidal surgery","url":"https://doi.org/10.3171/2014.7.jns1471"}],"tags":["subtype-page","wave4","rare"],"related":["pituitary-tumours","somatotroph-pitnet","lactotroph-pitnet","gonadotroph-pitnet","thyroid"],"cancers":[],"sections":[],"technologies":["radiosurgery-srs"],"targets":[],"drugs":["pasireotide"],"companies":[],"institutions":[],"pathways":[],"terms":[],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"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"],"standardOfCare":[{"setting":"All cases","approach":"Transsphenoidal surgery after achieving euthyroidism; somatostatin analogues for residual disease; radiotherapy where medical control fails (ETA 2013).","refs":["pituitary-tumours","pasireotide","radiosurgery-srs"]}],"stateOfArt":[],"history":[],"pipeline":[],"openProblems":[],"parent":"pituitary-tumours"},"route":"/cancers/thyrotroph-pitnet/","neighbours":{"cancer":[{"id":"gonadotroph-pitnet","kind":"cancer","name":"Gonadotroph pituitary neuroendocrine tumour (non-functioning adenoma)","route":"/cancers/gonadotroph-pitnet/"},{"id":"lactotroph-pitnet","kind":"cancer","name":"Lactotroph pituitary neuroendocrine tumour (prolactinoma)","route":"/cancers/lactotroph-pitnet/"},{"id":"pituitary-tumours","kind":"cancer","name":"Pituitary tumours (pituitary neuroendocrine tumours) and pituitary carcinoma","route":"/cancers/pituitary-tumours/"},{"id":"somatotroph-pitnet","kind":"cancer","name":"Somatotroph pituitary neuroendocrine tumour (acromegaly)","route":"/cancers/somatotroph-pitnet/"},{"id":"thyroid","kind":"cancer","name":"Thyroid cancer","route":"/cancers/thyroid/"}],"technology":[{"id":"radiosurgery-srs","kind":"technology","name":"Stereotactic radiosurgery (Gamma Knife, CyberKnife, linac SRS)","route":"/technologies/radiosurgery-srs/"}],"drug":[{"id":"pasireotide","kind":"drug","name":"Pasireotide","route":"/drugs/pasireotide/"}]}}