Polyuria due to central diabetes insipidus presenting as an early manifestation of acute myeloid leukemia.

Diabetes insipidus is a polyuric syndrome characterized by a pathologic excretion of large amounts of urine with low osmolality. It can originate from a total or partial lack of antidiuretic hormone (ADH) production from the pituitary gland or from “resistance” of the collecting tubules of the kidney to the ADH. Acute monocytic leukemia infiltrates the central nervous system in up to 50% of cases. In contrast, the infiltration of the pituitary gland by leukemia cells1-3 is unusual. As will be described in this case, on rare occasions, polyuria as a result of central diabetes insipidus can precede the manifestation of leukemia.