Richard Mitchell / Retna Digital 1 / 4
Richard Mitchell / Retna Digital 1 / 4

Adam Yauch's mother has spoken out about her son's "courageous" battle with cancer, insisting the Beastie Boys star remained "hopeful" right up until the end.

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The rapper, known as MCA, passed away on Friday at the age of 47 following a three-year struggle with the disease after doctors discovered a tumour in his salivary gland in 2009.

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Yauch's mother Frances has now revealed the star was admitted to hospital on April 14, but his condition deteriorated rapidly over the last two weeks and he died in his hometown of New York City with his wife, Dechen Wangdu, and 13-year-old daughter, Tenzin, at his bedside.

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She tells the New York Times, "He was a very courageous person. He fought a long battle with cancer. He was hopeful to the very end... It all just seemed to happen overnight... He was a terrific guy and had a brief but really wonderful life. We are really proud of him."