Acute adrenal insufficiency due to symptomatic Rathke's cleft cyst

A 65-year-old Japanese man who suffered from secondary hypopituitarism due to Rathke's cleft cyst is reported. Although computed tomography failed to detect any pituitary abnormality, magnetic resonance imaging demonstrated the presence of a cystic intrasellar mass, initially suggesting craniopharyngioma or abscess. Operative findings revealed Rathke's cleft cysts within the pituitary fossa which resulted in secondary hypopituitarism. Among cases of secondary hypopituitarism with abnormal findings in the pituitary, symptomatic Rathke's cleft cysts should be included in the differential diagnosis of adrenal insufficiency.