The former pop star has revealed she was terrified when she was rushed to hospital two months ago to have the growth removed and was worried that the "worst case scenario" would happen - leaving her adopted children Magdalena, six and Zac, five, without a mother.
She said: "I went for my annual check-up and there was the tumour. It was the size of a large fist.
"[I feared] the worst case scenario - I only adopted my babies a few years ago and they`re still so young. I really believe in God so I started praying like crazy."
Luckily the 42-year-old personality - who once dated Simon Cowell and has appeared on `The X Factor` as his assistant - was given the all-clear.
Explaining her relief, she said: "I can only describe it as being born again. I must have been really panicking inside because the relief was so tremendous. All I could think about was my babies and my mum."
Now she`s back to fighting fit, Sinitta has her hopes pinned on a role in the American version of `The X Factor`.
She told New! magazine: "I told Simon the night before I went into hospital. He was quite stunned but positive.
"I`d love my usual role or a judge`s role."
The brunette also hopes she won`t be snubbed in favour of judge Cheryl Cole, who is rumoured for a role stateside.
She admitted: "I`d be miserable. The only thing he could do to make it up to me would be to make me a judge on the UK version."