JOAN RIVERS is set to go under the knife yet again – the comedienne has filmed a cameo appearance for the last ever episode of plastic surgery drama NIP/TUCK.

The show was recently cancelled by TV bosses six years after it premiered, prompting producers to line up a star-studded final show.

The surgically-enhanced 76 year old is refusing to reveal what happens in her episode, telling AOL Television, “I’m in the finale. We already taped it. I’m sworn to secrecy about what I did, though. On that show, they only send you your pages for what you’re filming.

“And she admits she’s devastated the series is coming to an end: “But how sad is it that that show is ending? It’s such a great show. I think they just kind of ran out of (stories). They ran out of plastic surgery procedures… Do you know how sad that made me?”