[Secondary pan-hypophysitis caused by rupture of Rathke's cleft cyst: case report].

We report a case of secondary hypophysitis caused by rupture of Rathke's cleft cyst. A 30-year-old woman was admitted to our hospital with complaints of polyuria and left visual acuity impairment. These symptoms were preceded by aseptic meningitis one month prior to admission. An MRI on admission showed a suprasellar cystic mass and a swelling pituitary stalk. The mass was partially resected via the transsphenoidal approach. Pathological diagnosis was adeno- and neuro-hypophysitis and ruptured Rathke's cleft cyst. These findings strongly suggested that the hypophysitis was caused by rupture of Rathke's cleft cyst. After the operation, the patient's visual acuity improved with steroid administration. An MRI performed 5 months after the operation showed marked reduction of the mass. To our knowledge, there have been only 5 reports of secondary hypophysitis caused by ruptured Rathke's cleft cyst.