LONDON (Reuters) – Sarah Ferguson, the Duchess of York, has been diagnosed with a form of skin cancer, British media reported on Sunday, in another health problem for a member of Britain’s royal family. Ferguson, 64, who was married to Prince Andrew, was treated for breast cancer last year and has now been diagnosed with malignant melanoma after several moles were removed. “She is undergoing further investigations to ensure that this has been caught in the early stages,” Sky News quoted her spokesman as saying. “Clearly, another diagnosis so soon after treatment for breast cancer has been dist…