NEUROENDOCRINE CLINICAL CENTER BULLETIN Thyrotropin-secreting Pituitary Adenomas: Pitfalls in Diagnosis and Management

(SHBG): 73 nmol/l (normal, 13 to 71). His serum testosterone and the cortisol response on cosyntropin stimulation testing were normal. A presumptive diagnosis of a thyrotropin and growth hormone co-secreting pituitary adenoma was made. Octreotide LAR therapy was advised preoperatively to control thyroid hormone excess. He underwent transsphenoidal resection of the sellar mass, which was consistent with a pituitary adenoma on pathologic examination, showing immunoreactivity for thyrotropin, growth hormone and alpha subunit. Six weeks later, there was no evident pituitary tumor on postoperative MRI examination. In addition, serum thyrotropin, fT4, total T3 and IGF-1 were normal.