Transspenoidal hypophysectomy of a patient with Cushing's disease and an empty sella after treatment with etomidate

History and admission findings: A seventy-year-old woman was admitted to our hospital under suspicion of an adrenal Cushings's syndrome. Initial laboratory values showed elevated cortisol (834 nmol/l; normal: 180-640) which could not be suppressed after administration of 2 mg dexamethasone (632 nmol/l). Computed tomography of the abdomen showed a 19 x 34 mm mass in the region of the left adrenal gland. Investigations: ACTH levels were normal (42 ng/ml; 17-52). Serum cortisol remained high at 1021 nmol/l after administration of 8 mg dexamethasone. Four more doses of 2 mg dexamethasone were applied on 3 consecutive days, leading to a mild suppression of serum cortisol to 705 nmol/l, with urine cortisol levels dropping from 1915 to 101 nmol/l/24h. The CRH-test produced a rise of serum cortisol from 895 to 1475 nmol, with ACTH rising from 42 to 68 pg/ml, a laboratory constellation consistent with the diagnosis of centrally located Cushing's syndrome (Cushing's disease). MRI failed to show an adenoma of the pituitary gland so that sinus petrosus sampling was done to confirm the diagnosis (ACTH central/peripheral 7:1; normal range < 2:1). Treatement and course: Serum cortisol rose to 1070 nmol/l and the patient developed pneumonia and contracted tinea. Prior to surgery we lowered the excessive cortisol levels with etomidate and successfully treated the pneumonia with antibiotics. Postoperatively clinical symptoms of Cushing's syndrome disappeared. The patient now presented with total insufficiency of the anterior pituitary. Conclusion: Exact hormone testing that may involve sinus petrosus sampling is necessary in diagosing Cushing's syndrome. Even if radiological procedures cannot show an adenoma of the pituitray, transsphenoidal resection should be considered. Etomidate can lower excessive cortisol levels in seriously ill patients.