ODP587 A Case of Rathke'S Cleft Cyst Presented With Central Diabetes Insipidus In A Young Female

INTRODUCTION: Rathke's cleft cysts (RCC) are cystic sellar and suprasellar lesion derived from remnant of Rathke's pouch. RCC are mainly asymptomatic, but can present with headache, visual disturbance, panhypopituitarism, hypothalamic dysfunction when it enlarges causing compression to the surrounding structure. Diabetes insipidus as a presenting feature of RCC is rare. Even it presents with diabetes insipidus, it occurs more in elderly. CLINICAL CASE: A 32-year-old married female, mother of one child, having normal menstrual cycle presented with polyuria, polydipsia of recent onset. Clinical examinations was normal. Serum creatinine, potassium, calcium, plasma glucose were within normal range. Anterior pituitary hormonal evaluation was normal. Serum sodium was in the upper range of normal. Basal urine osmolality and serum osmolality were 87.49 mosm/kg (150 -1150 mOsm/kg) and 287 mOsm/kg (275 -295 mOsm/kg) respectively. Water deprivation test followed by vasopressin challenge test was done, which revealed partial central DI. Magnetic resonance imaging revealed a sellar cystic lesion hyperintense on both T1 and T2 weighted images, suggestive of rathke's cleft cyst and posterior pituitary bright spot was not visible. Tablet desmopressin 50 mcg twice daily was given and within two days patient responded well to the treatment. Urine volume reduced to 2.5 litres/day and water intake reduced to 3. 0 litres/day. CONCLUSION: This is a rare case of Rathke's cleft cyst, presenting as diabetes insipidus as the sole manifestation in a young lady. Presentation: No date and time listed