British actor and comedian Stephen Fry says he's undergone treatment for an aggressive prostate cancer.

In a video posted on his website—named "mischievous" after his doctor's description of his initial test results—Fry said he was diagnosed with a late-stage prostate cancer around Christmas time and underwent surgery to remove his prostate last month.

Fry described his cancer as "a rather aggressive little bugger" but said his surgery appears to have been successful pending further medical tests, and said that he's currently "fit and well and happy."

Fry—who starred in Blackadder, Wilde and Bones—said he went to his doctor for routine medical tests in December but that the doctor called him the next day saying his PSA levels—'prostate specific antigens' which, he explained, signpost if a prostate is under attack—were high.

Following further tests and a surgical biopsy on his prostate, doctors confirmed Fry had cancer.

Fry said: "They took these two bits out of me just to be sure... I got the results the next day and, yes indeed, there is a cancer there. These things are graded, there's a grading system for prostate cancers called the Gleeson Score and my score was 8 [out of 10] which is high enough to warrant some sort of treatment."

Fry said he was given the option of radiotherapy or surgery to remove the prostate and he chose the latter, and underwent the invasive procedure last month which he said "all seemed to go pretty well."

"They took the prostate out, they took out eleven lymph nodes, and the various bits that were taken out were examined and it turned out I had a Gleeson Score of 9, not 8, and considering 10 is the maximum this was clearly a rather aggressive little bugger," he said.

The TV and social media star said that he won't be entirely certain if the cancer has gone until his PSA levels are checked again and, if there's any cancer remaining, he may have to begin other forms of treatment such as radiotherapy and "the whole damn thing will start again."

However, he added: "For the moment I'm fit and well and happy and I just wanted to let you know because rumours had started to swirl. Goodness knows I'm not the most important person in the world but if you are ever on television and do things in the public eye people naturally seem to exhibit great interest and a newspaper had called up. I thought before the gossip gets silly and ill-informed I might as well come clean."

Fry has been recovering in private with the support of his family and doctors and said he hadn't said anything publicly up until now as he didn't feel well enough to read and respond to messages of sympathy and support.

"Cancer in the end is just a word that rings in your head," said Fry. "Cancer, I've got cancer, good heavens Stephen you're not supposed to get cancer. I know it's an old cliche but you don't think it's going to happen to you—cancer is something that happens to other people.

"You're probably now looking into my eyes and saying 'oh yes I can see he's a kind of cancery person, I can see that now.' That's how one looks at people who've got cancer—you always wonder if there's a particular aura they give off. Cancer, what a horrible word it is."

Fry paid tribute to the medical staff who helped him and finished his video: "Here's hoping I've another few years left on this planet because I enjoy life at the moment and that's a marvellous thing to be able to say and I'd really rather it didn't go away."