Diagnosis and Treatment > Signs and Symptoms
Search for other papers by Hui Yi Ng in
Google Scholar
PubMed
Search for other papers by Divya Namboodiri in
Google Scholar
PubMed
Search for other papers by Diana Learoyd in
Google Scholar
PubMed
Search for other papers by Andrew Davidson in
Google Scholar
PubMed
Search for other papers by Bernard Champion in
Google Scholar
PubMed
Search for other papers by Veronica Preda in
Google Scholar
PubMed
Summary
Co-secreting thyrotropin/growth hormone (GH) pituitary adenomas are rare; their clinical presentation and long-term management are challenging. There is also a paucity of long-term data. Due to the cell of origin, these can behave as aggressive tumours. We report a case of a pituitary plurihormonal pit-1-derived macroadenoma, with overt clinical hyperthyroidism and minimal GH excess symptoms. The diagnosis was confirmed by pathology showing elevated thyroid and GH axes with failure of physiological GH suppression, elevated pituitary glycoprotein hormone alpha subunit (αGSU) and macroadenoma on imaging. Pre-operatively the patient was rendered euthyroid with carbimazole and underwent successful transphenoidal adenomectomy (TSA) with surgical cure. Histopathology displayed an elevated Ki-67 of 5.2%, necessitating long-term follow-up.
Learning points:
-
Thyrotropinomas are rare and likely under-diagnosed due to under-recognition of secondary hyperthyroidism.
-
Thyrotropinomas and other plurihormonal pit-1-derived adenomas are more aggressive adenomas according to WHO guidelines.
-
Co-secretion occurs in 30% of thyrotropinomas, requiring diligent investigation and long-term follow-up of complications.
Search for other papers by I R Wallace in
Google Scholar
PubMed
Search for other papers by E Healy in
Google Scholar
PubMed
Search for other papers by R S Cooke in
Google Scholar
PubMed
Search for other papers by P K Ellis in
Google Scholar
PubMed
Search for other papers by R Harper in
Google Scholar
PubMed
Search for other papers by S J Hunter in
Google Scholar
PubMed
Summary
TSH-secreting pituitary adenomas are rare and the optimal investigation and management is uncertain. We describe a case of a 43 year-old woman with a TSH-secreting pituitary adenoma, highlighting diagnostic testing and our use, pre-operatively of somatostatin analogue therapy, which induced biochemical euthyroidism and a reduction in tumour size.
Learning points
-
The differential diagnosis of the syndrome of inappropriate TSH secretion is non-thyroidal illness, medications, assay interference due to heterophilic antibodies, thyroid hormone resistance and TSH-secreting pituitary adenoma.
-
TRH stimulation test and triiodothyronine suppression test assist in differentiating thyroid hormone resistance and TSH-secreting pituitary adenoma.
-
Somatostatin analogue therapy can induce biochemical euthyroidism and reduce tumour size.