My friend has a history of thyroidectomy for cancer several years ago. She also had a complete hysterectomy for endometriosis two years ago. Her thyroid surgeon recently checked her thyroid lab levels and also checked her estrogen levels. The thyroid levels were fine but her estrogen levels were surprisingly elevated. He has sent her back to her Gyn surgeon for a check up. What could be causing elevated estrogen levels if she has no ovaries?