Endocrine Abstracts

Introduction: Thyrotropinomas are rare pituitary tumours. Neurosurgery is considered the first-line treatment, followed by medical therapy with somatostatin analogues or radiotherapy.

Case reports: We present two cases of thyrotropinomas with different therapeutic approaches. Case 1: A 63-year old man presented with severe thyrotoxicosis. Biochemical evaluation showed inappropriate TSH secretion (TSH=7.5 mU/l, FT₄=45.5 pmol/l); computed tomography revealed a pituitary macroadenoma (2.37/2.56 cm). The patient underwent preoperative lanreotide and antithyroid drugs preparation before trans-sphenoidal tumour removal. Immunohistochemistry showed a pure thyrotropinoma. After neurosurgery, he had complete disease remission without any antithyroid medication and no signs of recurrence after 7-year follow-up. However, he developed postoperative gonadotropin deficiency.

Case 2: A man, 36-years, with total thyroidectomy for thyroid follicular adenoma presented with high TSH (15 mU/l) although he received daily 100 μg of levothyroxine and serum thyroid hormones were in high-normal concentrations (total T₄=11 μg/dl). Adding T₃ (20–30 μg/day) to T₄ treatment, TSH was still high (between 41 and 18.4 mU/l for FT₄ between 1.28 and 2 ng/dl), showing inadequate TSH secretion. Pituitary MRI revealed a 1.62/1.45/1.6 cm mass. Acute octreotide test showed decreasing of TSH from 22.4 to 0.53 μU/ml with no change in serum T₄ and T₃ levels. The patient refused surgery and received chronic treatment with long-acting octreotide, 20 mg/month. Along 3-year follow-up he had good biochemical response (TSH between 4.35 and 2.87 mU/ml while normal T₄ and T₃ levels under substitution) and ~25% reduction of tumor dimensions (1.21/0.92/1.29 cm). Whenever octreotide was stopped, inappropriate TSH secretion relapsed.

Conclusions: Neurosurgery is the treatment of choice in thyrotropinomas but when surgery is refused somatostatin analogues are an efficient alternative for long-time disease control.

Disclosure: This work received financial support through the project entitled ‘CERO – Career profile: Romanian Researcher’, grant number POSDRU/159/1.5/S/135760, cofinanced by the European Social Fund for Sectoral Operational Programme Human Resources Development 2007-2013.