West mum dies in op.
Dr Donda West, 58, who was also his manager, suffered "complications" after the unknown op.
Kanye, 30, was extremely close to his mum, the inspiration for his song Hey Mama.
She raised him alone after divorcing his dad Ray, an ex-Black Panther activist, when he was three.
The hip hop artist was in London when he was told the devastating news and jetted back to the US.
Kanye's writing partner, Rhymefest, said: "She was everyone's mum.
"A spirit never dies, a spirit lasts for ever."