Arginine vasopressin deficiency (central diabetes insipidus) with partial empty sella: a case report.

Background: Arginine vasopressin deficiency (central diabetes insipidus) is defined as a reduction in the release of arginine vasopressin (AVP) resulting in a variable degree of polyuria. Partial empty sella refers to an enlarged sella turcica that is not completely filled by pituitary gland. It can be either primary or secondary and its manifestation ranges from asymptomatic cases to isolated posterior pituitary, isolated anterior pituitary or both anterior and posterior pituitary dysfunctions. Diabetes insipidus caused by a partially empty sella is rare.

Case presentation: The patient, an 18-year-old Ethiopian woman who presented with long standing headache, increased urination, increased thirst, absence of menses and weight loss. Urine and serum osmolality was done and suggested diabetes insipidus. On further workup, brain magnetic resonant imaging was done and partially empty sella was diagnosed.

Conclusion: Diabetes insipidus secondary to partially empty sella is uncommon. In patients presenting with headache and anterior or posterior pituitary dysfunction, empty sella should be considered, whether partial or complete.