Ectopic ACTH syndrome due to clear cell sarcoma of the kidney

The 7-year-old girl presenting with cushingoid appearance and gross hematuria was found to have a right renal tumor. Preoperative hormonal assay revealed an extremely high plasma ACTH level and elevated plasma cortisol levels. Right radical nephrectomy was performed, and pathology proved the tumor to be a clear cell sarcoma, a sarcomatous variant of Wilms' tumor, of the kidney. Postoperative plasma ACTH level declined dramatically and cortisol levels returned to normal, too. She received chemotherapy and radiotherapy then and gradually lost her cushingoid appearance. This is the first reported case of clear cell sarcoma of the kidney with ectopic ACTH syndrome.