A rare association between Rathke's cyst and hypophysitis in a patient with delayed sex development and growth failure.

We report an 18-year-old Japanese male with a lack of secondary sex characterization and growth failure caused by a rare association between Rathke's cyst and hypophysitis. He was referred to us because of delayed secondary sex characterization. Endocrinological examination showed panhypopituitarism, and the replacement of hydrocortisone, levothyroxine, and desmopressin acetate (DDAVP) was initiated. Brain magnetic resonance imaging (MRI) showed a suprasellar region and a swollen pituitary stalk. The mass was partially resected using the transsphenoidal approach. The pathological diagnosis was hypophysitis and Rathke's cyst. Follow-up MRI performed 1 year after surgery showed that the size of sellar region had not changed. After surgery, in addition to pre-operative hormonal replacement, growth hormone and testosterone were initiated. Two years later, the size of sellar region remains unchanged. In conclusion, while an association between Rathke's cyst and hypophysitis is rare, we suggest that this condition should be included in differential diagnosis of the sellar region, even in adolescents.