To describe a patient with corticotropin-independent Cushing syndrome previously diagnosed and treated as congenital adrenal hyperplasia (CAH).We describe the initial manifestations, clinical investigations, and postoperative follow-up of the patient and review similar cases in the literature.A 5 and 9/12-year-old girl who was initially diagnosed and treated as having CAH and was noncompliant with glucocorticoid therapy presented with weight gain, hypertension, and a mass in the lower abdomen. On physical examination, she was a cushingoid-appearing girl with proximal muscle weakness and notable facial acne. Laboratory findings included elevated serum testosterone, 17-hydroxyprogesterone, dehydroepiandrosterone sulfate, androstenedione, estradiol, and cortisol, as well as elevated urinary cortisol and cortisone. Serum corticotropin was undetectable. She had normal serum electrolytes and plasma renin activity. Computed tomography scan of the abdomen and pelvis showed a cystic mass with a focal enhancing solid component arising from the right ovary, which was subsequently determined to be a steroid cell tumor not otherwise specified.Although ovarian steroid cell tumors typically secrete gonadal steroids, the rare steroid cell tumors not otherwise specified can secrete both glucocorticoids and gonadal steroids and are an unusual cause of Cushing syndrome.