Patients with Cushing's disease usually present typical clinical and biological features easily leading to the diagnosis. However very atypical presentations of the disease do exist especially in the intermittent forms and several investigations are often necessary to detect pituitary microadenoma wich sometimes is inconspicuous. The course of the disease can be serious and might responsible of definitive sequellas wich can threaten patient's life. Therefore rapid treatment is recommended. Pituitary surgery should be considered as the major therapeutic approach; however, in severe cases or when pituitary-directed treatments or OP'DDD have failed, total bilateral adrenalectomy should be proposed.