Endocrine Abstracts

Introduction

Thyrotropin-secreting pituitary adenomas (TSH-omas) are rare. For this reason each case of TSH-secreting pituitary tumor can help expand extensive clinical experience in world practice.

Materials and methods

We included 40 patients with TSH secreting pituitary adenomas. Hormonal profile: TSH (0.25-3.5 mIU/L), FT4 (9-20 pmol/l) FT3 (2.5-5.5 pmol/l) were measured by Architect i2000SR (Abbott Laboratories, Abbott Park, Illinois, U.S.A). MRI was performed on GE Optima MR450w 1.5T.

Results

Forty patients with TSH-omas were under observation in our center from 2010 to 2020. The median age was 46 [32; 57] with a predominance of female (31 cases) over male (9 cases). Clinical manifestations included cardiac arrhythmias (80%); neurological changes (60%), impairment of bone metabolism (51.35%) hypopituitarism (10%) visual impairment (10%). At the beginning of the observation, 17 patients had increased TSH, FT3 and FT4 levels; in 10 patients FT3 and FT4 only; 5 patients had elevated TSH and either FT3 or FT4, and in 8 — an increase in one of the hormones. Mean value of TSH was 4.28 [2.4; 6.4] mIU/L, FT4 — 23.03 [20.03; 29.37] pmol/l, FT3 – 7.2 [5.9; 10.09] pmol/l. Sex steroid binding globulin, C-terminal telopeptide and osteocalcin were elevated in 62.86%, 62.07% % and 48.15% of cases, respectively. In 75% of cases short-term octreotide treatment led to thyroid hormone normalization. On MRI macroadenomas were registered in 72.5% cases. In 1 case there was no pituitary adenoma on MRI. In 20 patients, diagnosis was finally confirmed by immunohistochemical examination. In 13 patients, the diagnosis verification was based on remission after surgical or medical treatment. In the remaining 7 cases, the diagnosis was made on clinical and laboratory data. Remission was achieved in 33 patients: 25 (75.76%) after neurosurgery, 3 received treatment with somatostatin analogues and 5 required somatostatin analogues after neurosurgery; 2 out of 7 patients who did not achieve full remission were lost for observation.

Conclusion

At the time of diagnosis 72.5% of patients had macroadenomas and 80% had cardiac arrhythmias, suggesting a long duration of disease. However less than 50% of patients had all tests elevated emphasizing the necessity of multiple hormone testing and complex diagnostic evaluation.