Recurrence of TSHoma – A life threatening illness… (#356)
A 44 year old female presented with typical symptoms of hyperthyroidism including lethargy, tremor, palpitations, weight loss and anxiety treated with high doses of benzodiazepines. Initial investigations showed elevated thyroid hormones without TSH suppression, mild thyroid enlargement with uniform increased uptake on thyroid scan and was placed on anti-thyroid medications by the GP.
Upon review by Endocrinology the patient had developed hypothyroid symptoms with consistent reductions in thyroid hormones. The anti-thyroid medication was ceased.
Following this the Thyroid function tests once again showed elevated thyroid hormones without suppression of TSH. The discordant results were reproduced at 3 laboratories with the TSH each time in the normal range and fT3 significantly elevated above 10pmol/L. TRH stimulation test did not induce a significant TSH response which does not support thyroid hormone resistance.
Examination revealed a diffusely enlarged thyroid gland and eye examination revealed tented visual fields. Pituitary-MRI showed macroadenoma abutting the optic chiasm.
The patient was referred for transphenoidal surgery and was placed on a somatostatin analogue pre-operatively with improvement in thyroid symptoms and normalisation of thyroid hormone levels. Post-operatively there were no hormone deficiencies and the somatostatin analogue was ceased. Three months post-operatively the patient’s palpitations ceased, she gained weight and her anxiety improved allowing detoxification from benzodiazepines.
Unfortunately 6-months later the major symptom-anxiety, returned associated with other hyperthyroid symptoms and persistently elevated fT3 levels with normal TSH levels. The patient described suicidal thoughts secondary to extreme anxiety causing significant impact on lifestyle being unable to leave her house and go to work. On repeating pituitary-MRI, the sphenoid sinus was suspicious for recurrence of TSHoma. Again treatment with long-acting somatostatin analogue was commenced.
The long-acting somatostatin analogue treatment was associated with a dramatic improvement in the patients’ mental health through reduction in anxiety levels, resolution of insomnia, palpitations and tremor . Also the fT3 levels normalised and the biochemical response was supported by reductions in Sex Hormone Binding Globulin levels. The patient is currently stable on long-acting somatostatin analogues and returned to work.
Optimal management strategies for TSHoma
The role of SHBG in diagnosis and monitoring response to therapy in central hyperthyroidism
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- TSH secreting adenomas. Beck-Peccoz, P et al. Best Practice & Research Clinical Endocrinology & Metabolism, 2009, 23, 597–606.
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