Endocrine Abstracts

The perioperative management of pituitary tumours presents complex challenges, particularly when complicated by panhypopituitarism and arginine vasopressin deficiency (AVP-D). We present the case of a 22-year-old male referred by ophthalmology with rapidly progressive visual loss. Orbital MRI revealed a large predominantly cystic suprasellar mass with internal calcification, compressing the optic chiasm and displacing the midbrain. Differential diagnoses included craniopharyngioma, germinoma, and optic pathway glioma. On endocrine review, the patient demonstrated florid features of AVP-D, reporting polyuria of 8–10 L/day and severe polydipsia, which had been previously misattributed to behavioural causes. Initial investigations confirmed panhypopituitarism, with very low thyroid hormones, testosterone, prolactin, and a random cortisol of 76 nmol/l. He was commenced on hydrocortisone and desmopressin (AVP analogue) with clinical improvement. Neurosurgical intervention included preoperative external ventricular drain, subsequent craniotomy, tumour debulking, and shunt insertion. Postoperative imaging confirmed a small residual tumour, hypothalamic involvement, and no significant hydrocephalus. Complications included severe bilateral visual loss, hypothalamic syndrome, and Charles Bonnet visual hallucinations. The patient was placed on active radiological surveillance with consideration of postoperative radiotherapy, including proton beam therapy, pending recovery. A significant perioperative learning point arose when omission of desmopressin during an admission with intercurrent infection led to profound hypernatraemia (serum sodium 195 mmol/l), manifesting as irritability and confusion. He required intensive care admission for careful correction of hypernatraemia and reinstatement of desmopressin. This incident highlighted the critical importance of meticulous perioperative endocrine management and the need for heightened awareness among general medical teams of the potentially fatal consequences of desmopressin omission in AVP-D. This case underscores the multi-disciplinary complexities of managing large suprasellar tumours with hypothalamic and pituitary involvement. It reinforces the necessity of proactive endocrine input throughout the perioperative pathway, strict protocols for AVP-D management, and robust communication across teams. Recognition of AVP-D as a life-threatening condition is paramount, as failure to provide timely replacement can result in catastrophic outcomes. In conclusion, our patient illustrates the spectrum of challenges in the perioperative care of pituitary tumours: balancing neurosurgical intervention, long-term surveillance, and rigorous endocrine replacement. Vigilance in AVP-D management, alongside comprehensive multidisciplinary collaboration, is crucial to optimising patient safety and long-term outcomes.