Pre-existing undiagnosed central diabetes insipidus unmasked after renal transplantation.

Central diabetes insipidus (CDI) is characterized clinically by the presence of polyuria with the subsequent development of volume depletion and hypernatremia. In patients with dialysis-dependent end-stage renal disease (ESRD), neither of these findings can be expressed due to the absence of renal function. A 59-year-old woman with anuric ESRD of unknown etiology had been on peritoneal dialysis for 8 years prior to receiving a cadaveric allograft. Postoperatively, she developed persistent polyuria and hypernatremia. A desmopressin test confirmed the diagnosis of CDI. A magnetic resonance imaging (MRI) of the brain revealed an empty sella turcica. Maintenance therapy with intranasal desmopressin resulted in complete resolution of the polyuria. At 6-month follow-up on daily desmopressin, the patient maintains normal serum sodium levels and stable allograft function. This is a unique case of CDI from empty sella syndrome (ESS) that was unmasked only after the restoration of normal renal function following successful renal transplantation.