Abstract
Cushing syndrome resulting from adrenocortical carcinoma in pregnancy is exceedingly rare. There are no validated guidelines to establish a diagnosis or guide management in pregnancy. We provide a case of a 31-year-old woman presenting for management of diabetes in pregnancy who appeared cushingoid. She was subsequently diagnosed with ACTH-independent Cushing syndrome and experienced preterm labor at 33 weeks' gestation, delivering a healthy infant. Four weeks postpartum, the patient underwent a left adrenalectomy and was subsequently diagnosed with adrenocortical carcinoma.