Endocrine Abstracts

Introduction: Craniopharyngiomas are rare tumors which are typically located in the sellar and suprasellar region. They can be solid or mixed, cystic-epithelial. Treatment options include surgery, radiation or intracystic therapy. Adipsic diabetes insipidus is a rare, life-threatening disease which can sometimes be associated with craniopharyngioma, either because of tumor mass effect, or as a postprocedure complication. Ultimately, this can cause severe hypernatremia, so long term management requires a careful interplay between low dose vasopressin analog treatment and fluids.

Case report: We present the case of a 32-year-old patient, operated at 10 years for craniopharyngioma, relapsed and re-operated (a total of 5 interventions), complicated with hydrocephalus (for which a ventriculo-peritoneal shunt was inserted), panhypopituitarism (in substitution treatment with LT4, cortison acetate and testosterone), central diabetes insipidus (in treatment with vasopressin analogues) and hypothalamic syndrome (hyperphagia, somnolence, hyperhidrosis, adipsia, hyperthermia). The last cerebral MRI (2021) describes postoperative continuity defects and altered structure of the sellar region and floor of the anterior cerebral fossa, and possible remaining pituitary tissue of 9/3 mm. In october 2023, he presents for reevaluation, accusing: sleepiness, night vision disorders, hyperphagia, adipsia, pain in the lower limbs, generalized muscle weaknes and adipsia. Clinical exam revealead a BP of 109/65mmHg, a HR of 110bpm, and a BMI=40.16 kg/m², and a 24 hour urine ouput of 500 mL/day of hyperchromic, cloudy urine. Biochemical evaluation revealead hypernatremia (160 mmol/l), and hormonal evaluation revelead euthyroid status under LT4 substitution, normal cortisol (under 25mg cortison acetate/daily) and low testosterone levels (limited treatment compliance). Considering the severe hypernatremia, caused by adipsia and aggravated by diabetes insipidus, oral and parenteral fluid repletion was initiated and the dose of vasopressin analogues was considerably reduced, with subsequent normalization of serum sodium to 145 mmol/l, and a urine output of 2500mL/day (urine density 1000). Upon discharge, lower dose vasopressing analogue therapy was continued, and a minimum of 2L fluid intake was recommended.

Conclusion: Adipsic diabetes insipidus is a rare, life-threatening condition, which causes severe hypernatremia through intracellular dehydration, but also extracellular hyperhydration. The mainstay of therapy is a delicate balance between vasopressin analogue treatment and fluid intake; and an individual approach must be selected in the management of these patients. Finally, even with appropriate medical treatment, adipsic diabetes insipidus remains a hard to manage condition, so patient and family education regarding fluid intake as well as frequent, careful assessment of clinical and biochimical status is of utmost importance.