Thyrotropin-secreting Pituitary Adenomas: Report Of 5 Cases And Literature Review

Objective To investigate the clinical features,diagnosis and treatment of central hyperthyroidism due to thyrotropin-secreting pituitary adenomas.Methods Five patients with central hyperthyroidism due to thyrotropin-secreting pituitary adenomas from our hospital were enrolled from May 2010 to October 2016.The clinical manifestation,laboratory findings,imaging examination and histopathology of these patients were analyzed.Results There were 2 male cases and 3 female cases.The age ranges of the patients were 25 to 44 years,and the average age was 36.8.The average course was 2.3 years,in the range of 1 week to 10 years.Among them,one patient was misdiagnosed as Graves’ disease,and treated with antithyroidal therapy(methimazole)for 1 year.5 patients had different degrees symptoms of thyrotoxicosis,such as polyphagia,palpitation,hidrosis and tremors.Among them,1 case had amenorrhea,2 cases had acromegalia.The levels of serum free thyroxine(FT4)and free triiodothyronine(FT3)were elevated with thyroid stimulating hormone(TSH)increased or normal in all patients.Growth hormone(GH)level was elevated in one case,prolactin(PRL)was elevated in 1 case,and both GH and PRL were elevated in 1 case at the same time.TSH receptor antibodies(TRAb)were negative in all cases.MRI showed macroadenoma in 5 patients.Three patients had compression of optic chiasma,three patients had invasion of sphenoid sinus.Four patients underwent transspheniodal surgery,one experienced transcranial surgery.Histopathological examination showed thyrotropin-secreting pituitary adenoma in all cases,immunohistochemical analysis showed TSH positive immunoreactivity.Mixed adenomas were found in 3 cases,one case with GH positive immunoreactivity,1 case with PRL positive immunoreactivity,and 1 case with both GH and PRL positive immunoreactivity.Conclusion Attention should be paid to the hyperthyroidism patients with unsuppressed serum level of TSH.MRI examination is helpful in diagnosis of pituitary adenoma.The initial therapeutic approach is to remove the tumor mass surgically.