Endocrine Abstracts

55 year old male with 5 years of type 2 diabetes mellitus referred to clinic for consideration of Glucagon-like peptide-1 (GLP-1) agonist therapy. BMI of 45 kg/m², asthma, depression, hypertension and obstructive sleep apnoea (intolerant of CPAP). Noted to have large boggy feeling hands and feet, mild acanthosis nigricans and a deep voice. On enquiry, shoe size had increased from 8 to 12, wedding ring did not fit and weight gain and jaw protrusion had been noticed. Insulin-like growth factor 1 (IGF-1) was raised at 984 μg/l (49-191), Growth Hormone (GH) did not suppress with oral glucose tolerance testing: 3.9μg/l at 0 h and 2.8 μg/l at 2 h. Pituitary hormone screen showed no suppression. MRI of pituitary with contrast showed an expanded pituitary fossa with the normal pituitary on the right and a 15 x18 mm less enhancing lesion to the left, lying close to the optic nerve and slight extension towards the left cavernous sinus, in keeping with a pituitary macroadenoma, functioning as a GH secreting Pituitary Neuroendocrine Tumour (PitNET). Complications screen showed no formal visual field defect, echocardiogram showed no structural abnormalities, colonoscopy revealed a likely benign polyp (with a plan for biopsy) and there were no palpable thyroid nodules. Ongoing optimisation of diabetes management (GLP-1 agonist has improved HbA1 c to 47). The patient was discussed at pituitary MDT and seen by neurosurgeons, and has presently been waiting 13 months for operative management. IGF-1 was initially suppressed to 450μg/l on the somatostatin analogue Lanreotide 120 mg monthly. After several months the efficacy has reduced; IGF-1 was not suppressed at 950μg/l. He has now developed the complication of cholecystitis, so Lanreotide has been suspended and expedition of his surgery has been requested from the neurosurgeons.