AUTHOR=Huang Yijing , Wen Xiaoming , Liang Xinxin , Xu Lingling 

TITLE=Mixed thyrotropin-secreting pituitary neuroendocrine tumor coexisting with Graves' disease: a case report

JOURNAL=Frontiers in Medicine

VOLUME=Volume 11 - 2024

YEAR=2024

URL=https://www.frontiersin.org/journals/medicine/articles/10.3389/fmed.2024.1436400

DOI=10.3389/fmed.2024.1436400

ISSN=2296-858X

ABSTRACT=Background: Thyrotropin(TSH)-secreting pituitary neuroendocrine tumor (PitNET)      is recognized as a rare disease. Mixed TSH PitNETs accounted for 20-25% of all PitNETs. This study aimed to report an extremely rare case of mixed TSH PitNET coexisted with Graves' disease(GD) and review the literature.A 36-year-old male patient presented with both elevated levels of free triiodothyronine (FT3), free thyroxine (FT4) and insulin-like growth factor 1 (IGF-1), but non-suppressed thyroid-stimulating hormone (TSH) level. His antithyroglobulin antibody (TGAb), anti-thyroid peroxidase autoantibody (TPOAb), and thyrotropin receptor antibody (TRAb) were positive. The symptoms of palpitations, hyperhidrosis, heat intolerance, and irritability appeared 2 years before his admission.But he showed neither signs nor symptoms of acromegaly. Contrast-enhanced pituitary magnetic resonance imaging (MRI) showed enlarged pituitary fossa, with an irregular abnormal signal mass. The patient underwent endoscopic pituitary tumor resection via transsphenoidal approach. Postoperative pathology suggested mixed pituitary adenoma. At 8 months after surgery, the patient had postoperative recurrence of hyperthyroidism and methimazole(MMI) was then administered. The recurrence of TSH PitNET was confirmed by positron emission tomography-computed tomography (PET-CT) 11months after surgery and treatment with lanreotide was started.Gradually, his levels of FT3, FT4, TSH, TPOAb and TGAb became normal, and levels of TRAb and IGF-1 improved.When circulating levels of both FT4 and FT3 were upregulated, nonsuppressed TSH levels and positive thyroid antibodies were found, TSH PitNET coexisted with GD should be carefully taken into account to avoid the potential risk of treatment-induced tumor progression.