FCP2-377
A 45-year-old man presents with tiredness and central weight gain.
He underwent pituitary surgery for a non-functional pituitary tumour two years ago. Although he recovered from his pituitary surgery well, he has been found to have complete anterior hypopituitarism. Accordingly he is receiving stable replacement therapy with testosterone monthly injections, thyroxine and hydrocortisone.
On examination, there are no specific abnormalities, his vision is 6/9 in both eyes and he has no visual field defects.
From his notes, you see that he has gained 8 kg in weight over the last six months and his BMI is 31. His blood pressure is 122/72 mmHg.
Thyroid function tests and testosterone concentrations have been normal. A postoperative MRI scan report shows that the pituitary tumour has been adequately cleared with no residual tissue.
Which of the following is the most likely cause of his current symptoms?