Endocrine Abstracts

Introduction: Central diabetes insipidus (CDI) is a rare complication of acute myeloid leukemia (AML) occurring in less than 0.6% of patients. It is associated with genetic changes in chromosomes 3 and 7. CDI may precede; occur simultaneously or after the diagnosis of AML.

Case report: 51-year-old man, with no relevant past medical history, began complaining with polyuria, polydipsia, weakness and weight loss in March 2015.The patient was evaluated in the emergency department in June and was discharged with the diagnosis of urinary infection. As the complaints persisted he was again evaluated presenting also dehydration and easy bruising. Analytical findings suggested AML (Hb 8.8 g/dl, leukocytes 13.03×10×9/l, neutrophils 0.87, blasts 46%) with karyotype 45,XY,inv (3) (q21q26), – 7 (20). He was admitted to Hematology Department and began chemotherapy. He also had hypernatremia, 159 mEq/l(135–145), with serum osmolality of 332 mosm/kg (282–300), urine osmolality in the lower limit of normal 187 mosm/kg (50–1200) and negative water balance, in this context endocrinology evaluation was requested. CDI was suspected and the patient started desmopressin with resolution of hyponatremia, polydipsia and polyuria. Pituitary CT revealed pituitary with normal morphology and dimensions, although a low uptake area in the median/ right paramedian region was assumed. He was discharged with oral desmopressin 0.06 mg bid. Asas the patient did not show response to induction chemotherapy,he begun salvage chemotherapy.Given the patient’s clinical context we decided not to conduct water restriction test and pituitary MRI was also delayed.

Conclusion: In this case the symptoms of diabetes insipidus led to the diagnosis of AML. There are descriptions in the literature that these cytogenetic changes are associated with the development of DCI in AML,although the causes of this association are not fully understood.