ABSTRACT
Cyclic Cushing's syndrome is a special manifestation of Cushing's syndrome, of which the serum cortisol is only periodically increased. The causes include Cushing' s disease, ectopic adrenocorticotropic hormone ( ACTH)-producing syndrome, and primary adrenal disease. It is difficult to diagnose because the cycle length varies from hours to years and the clinical signs may show spontaneous remissions and recurrent attacks. The detection methods include either measurement of serum cortisol, 24 h urinary free cortisol, early-morning urinary cortisol/creatinine, salivary cortisol or hair cortisol. No matter which method to be used, repeated and continuous measurement is essential. Here, we present a female patient who was diagnosed as cyclic Cushing's syndrome due to a pituitary ACTH adenoma. The clinical features, detection methods, diagnosis, and treatment strategies of cyclic Cushing' s syndrome are also reviewed in this article.