Recurrent ACTH-independent Cushing's syndrome in multiple pregnancies and its treatment with metyrapone

A 17-year-old primigravid woman presented with Cushing's syndrome. Typical clinical symptoms and signs developed at the beginning of pregnancy. By week 17 of gestation, plasma cortisol diurnal rhythm was absent and there was a paradoxical increase in plasma cortisol after a 1-mg dexamethasone overnight suppression test. Basal urinary free cortisol was 10 times above the upper limit (in pregnancy) and ACTH levels were suppressed. The diagnosis of ACTH - independent Cushing's syndrome was established. MRI scans revealed normal adrenal and pituitary glands. To control hypercortisolism, the patient was treated with metyrapone. At 34 weeks of gestation, the patient developed preeclampsia and underwent caesarean section. A female infant weighing 1070 g was delivered. No apparent metyrapone-induced teratogenic effects were observed. Cushing's syndrome in the patient resolved within three weeks of delivery. No corticosteroid replacement therapy either for child or mother was needed. Eight months after delivery the patient became pregnant again and rapidly developed Cushing's syndrome with typical clinical symptoms and signs and laboratory results (urinary free cortisol 6464 nmol/24 h). This second pregnancy was unwanted and terminated by artificial abortion that was followed by rapid resolution of hypercortisolism. A third pregnancy, 12 months after delivery was also accompanied by the rapid development of hypercortisolism which recovered after artificial termination. The mechanisms by which pregnancy-induced Cushing's syndrome occurred in this patient are unclear. Aberrant responsiveness or hyperresponsiveness of adrenocortical cells to a non-ACTH and non-CRH substance produced in excess in pregnancy should be considered. Metyrapone suppression of hypercortisolism currently represents the best treatment for these rare cases.