A Case of Mineralocorticoid-responsive Hyponatremia of the Elderly after Distal Pancreatectomy

Abstract

Mineralocorticoid-responsive hyponatremia of the elderly (MRHE) is a disease causing marked hyponatremia. The case of a patient who developed MRHE after distal pancreatectomy is presented. A 70-year-old man underwent investigations for poor blood glucose control that identified a tumor in the pancreatic tail, and he was referred to our hospital. Resectable pancreatic tail cancer was diagnosed on the basis of abdominal contrast-enhanced computed tomography and endoscopic ultrasound-guided fine needle aspiration. The patient underwent laparoscopic distal pancreatectomy. On postoperative day 15, the patient developed marked hyponatremia (114 mEq/l). Since the serum cortisol level was normal and the patient showed signs of dehydration, MRHE was diagnosed, and treatment with an oral mineralocorticoid was started. On postoperative day 24, serum sodium had improved to 138 mEq/l, and the patient was discharged. Serum sodium subsequently remained within normal limits, and the mineralocorticoid was discontinued 3 months after discharge.