Endocrine Abstracts

Behcet’s disease (BD) is a chronic disease characterised by systemic involvement of blood vessels of all sizes on both arterial and venous circulation resulting in recurrent ulcers. The posterior infundibulo-hypophysitis, causing DI, has been commonly reported in association with systemic inflammatory/autoimmune disorders, however there are a handful of cases presenting with DI and Behcet’s disease.

A 26-year-old African-American woman diagnosed with BD in 2006 after receiving a flu vaccine resulting in oral and genital ulcerations. She presented to ED with malaise, dizziness, severe polyuria, polydipsia with requests for iced water. On physical examination there was evidence of multiple oral apthous ulcers and genital ulcers. The serum level of sodium was 150 mEq/l, urine specific gravity was 1.003, and urine osmolality was 126 mOsm/kg. Estimated urine output volume was 5600 ml collected over 12 h. Complete evaluation of anterior pituitary hormone function tests including serum TSH, FT₄, FSH, LH, oestradiol, prolactin, IGF1, and ACTH stimulation test were unremarkable. MRI of the brain was suggestive of possible thickening of the pituitary stalk, but otherwise normal. Patient was started on oral DDAVP 0.1 mg twice daily with complete resolution of symptoms associated with DI. Formal water deprivation test was scheduled but not done due to a sudden resolution of DI over the course of 6 weeks.

Involvement of the CNS in Bechet’s can be severe, leading to a devastating neurological deficit. Central DI in patients with BD has been rarely reported with possible correlation to autoimmune mediated vasculitis involving the blood vessels supplying the hypothalamus. In contrast with all prior cases reported, our patient’s central DI had self-limiting course with complete resolution of symptoms (Molloy). Lymphocytic or autoimmune hypophysitis is commonly described as a transient but possibly relapsing condition.