Endocrine Abstracts

47 year old gentleman referred to Neurosurgery Department with incidental findings of pituitary macroadenoma with chiasmal compression and cavernous sinus involvement, whilst getting investigated for tinnitus. His past medical history included chronic migraines only. He has been experiencing increased frequency of migraines along with lethargy, decreased libido and loss of morning erections for some time prior to presentation. His formal visual fields showed a slight inferior temporal defect in right eye while left eye had a slight superior temporal defect. His 9am pituitary profile showed cortisol 286 mmol/l, TSH 1.76 mIU/l, T4 8.8 pmol/l, FSH 1.6 IU/l, LH 1.3 IU/l, IGF1 16.2 nmol/l, Testosterone 3.2 nmol/l, Prolactin 534 mIU/l. He was started on hydrocortisone, levothyroxine and testosterone gel. He underwent Transphenoidal Surgery soon after the diagnosis of pituitary macroadenoma. Histology showed gonadotroph adenoma with Ki 67<3%. Post-operative day two, 9 am pituitary profile showed cortisol 166 mmol/l, TSH 0.20 mIU/l, T4 11.0 pmol/l, FSH 1.6 IU/l, LH 0.8 IU/l, IGF1 nmol/l 15.1, testosterone 0.4 nmol/l, prolactin 141 mIU/l. He has experienced epigastric pain after starting hydrocortisone prior to surgery and was not keen to continue hydrocortisone postoperatively due to gastric side-effects. He was adviced hydrocortisone with PPI cover along with levothyroxine postoperatively. Awaiting his insulin tolerance test (ITT) to assess is hypothalamic pituitary axis post-surgery; he self-ceased his hydrocortisone amidst of pandemic. He was asked to restart on a reduced dose of 10 mg +5mg with lansoprazole considering his 9am cortisol was 163 mmol/l. After the pandemic, he underwent ITT (more than 1 year after surgery) that demonstrated a good cortisol response of 498 mmol/l but inadequate growth hormone response. He was asked to stop his hydrocortisone.

Conclusion: Sellar and parasellar masses are a common finding, and most of them are treated via trans-sphenoidal surgery. Hypopituitarism is one of the most frequent sequelae, with central adrenal insufficiency being the deficit that requires a timely diagnosis and treatment. The peri-operative management of adrenal insufficiency is influenced by the preoperative status of the hypothalamic–pituitary–adrenal axis. ITT is considered the gold standard for assessment of GH and ACTH reserve in patients with pituitary disease following pituitary surgery. It has been evidenced that recovery in pituitary function is seen during the late-postoperative follow-up. ACTH is known to recover most frequently however GH is shown to be least likely to recover.