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 ou r hospital under suspicion of an adrenal Cushings's syndrome. Initial labor atory values showed elevated cortisol (834 nmol/l; normal: 180-640) which c ould 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 reg ion of the left adrenal gland. Investigations: ACTH levels were normal (42 ng/ml; 17-52). Serum cortisol r emained high at 1021 nmol/l after administration of 8 mg dexamethasone. Fou r more doses of 2 mg dexamethasone were applied on 3 consecutive days, lead ing to a mild suppression of serum cortisol to 705 nmol/l, with urine corti sol levels dropping from 1915 to 101 nmol/l/24h. The CRH-test produced a ri se 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 centrall y located Cushing's syndrome (Cushing's disease). MRI failed to show an ade noma of the pituitary gland so that sinus petrosus sampling was done to con firm the diagnosis (ACTH central/peripheral 7:1; normal range < 2:1). Treatement and course: Serum cortisol rose to 1070 nmol/l and the patient d eveloped pneumonia and contracted tinea. Prior to surgery we lowered the ex cessive cortisol levels with etomidate and successfully treated the pneumon ia with antibiotics. Postoperatively clinical symptoms of Cushing's syndrom e disappeared. The patient now presented with total insufficiency of the an terior pituitary. Conclusion: Exact hormone testing that may involve sinus petrosus sampling is necessary in diagosing Cushing's syndrome. Even if radiological procedur es cannot show an adenoma of the pituitray, transsphenoidal resection shoul d be considered. Etomidate can lower excessive cortisol levels in seriously ill patients.