A case of Rathke's cleft cyst presenting with diabetes insipidus.

Rathke's cleft cysts (RCCs) are considered to arise from the remnants of Rathke's pouch, an invagination of the stomodeum. They are classically described as benign epithelium lined intrasellar cysts containing mucoid material, and also found in 2-33% of routine autopsy series. The most common presenting symptoms are visual impairment, hypothalamic dysfunction, hypopituitarism and headache. Diabetes insipidus has been described in patients with RCC. Very few cases presented with only diabetes insipidus in adults. To our knowledge, our patient is the first case of RCC presenting with only diabetes insipidus in childhood. A 9-year-old girl presented with diabetes insipidus. The physical, neurological and endocrinological examinations were normal, except for diabetes insipidus. Magnetic resonance imaging scan revealed a hyperintense lesion with supra sellar extension in the posterior pituitary both on T1 and T2 weighted images. Subtotal excision of RCC was performed via transsphenoidal surgery. However, diabetes insipidus persisted after the surgery.