Sarah the Duchess of York has been diagnosed with malignant melanoma skin cancer during treatment for previously diagnosed breast cancer, making her the third member of the royal family to have a medical announcement.

"She is undergoing further investigations to ensure that this has been caught in the early stages," her spokesperson said. “Clearly, another diagnosis so soon after treatment for breast cancer has been distressing but the Duchess remains in good spirits," the spokesperson said.

The melanoma was found as several moles were removed during a breast reconstruction procedure following her mastecomy. Melanoma is a very treatable cancer that is rarely fatal if it is caught early, but can be dangerous if it isn't.

Her representative said following the new diagnosis, “The Duchess wants to thank the entire medical team which has supported her, particularly her dermatologist whose vigilance ensured the illness was detected when it was. She believes her experience underlines the importance of checking the size, shape, color and texture and emergence of new moles that can be a sign of melanoma.”

"Very resilient"

The Duchess announced on New Year's Eve that she had beaten breast cancer and was presumably cancer free.

Sarah, formerly known as Sarah Ferguson or "Fergie," is the ex-wife of Prince Andrew and mother of Princess Beatrice and Princess Eugenie.

She and her daughters have worked with the Teenage Cancer Trust in the past, and Princess Beatrice is patron of the British Skin Foundation and has worked with skin cancer patients.

A friend told People she was “very resilient and in good spirits” after the diagnosis, although it was difficult so soon after the battle with breast cancer.

She spent time at MAYRLIFE clinic, a medical health resort in Altaussee, Austria, immediately following the diagnosis. “Her time in Austria helped her gather her strength,” the friend said. “And her family is supporting her.”

She is also receiving treatment in London.

Other royals in treatment

Just days earlier, Princess of Wales Kate Middleton had an unspecified abdominal surgery and will not be fulfilling her royal duties for several weeks as she recovers.

King Charles III also announced that he will be having prostate treatment this week.