Sarah Ferguson, Duchess of York, diagnosed with breast cancer ...

Sarah Ferguson, the Duchess of York, underwent surgery after a breast cancer diagnosis, her spokesperson confirmed Sunday. 

The cancer was detected during a routine mammogram, the spokesperson said. Her surgery for the cancer was successful.

"The Duchess is receiving the best medical care and her doctors have told her that the prognosis is good. She is now recuperating with her family," the spokesperson said. "The Duchess wants to express her immense gratitude to all the medical staff who have supported her in recent days."

Ferguson, widely known as Fergie, had been symptom-free. She emphasized the importance of regular breast cancer screening based on her experience, her spokesperson said. 

Her spokesperson did not specify when the Duchess of York was diagnosed or when she underwent surgery.

Ferguson, who used to be married to Prince Andrew, is mother to Princesses Beatrice and Eugenie of York.

She and her daughters have previously worked with the Teenage Cancer Trust.