"Hacksaw" Jim Duggan was back in the operating room on Friday ... the WWE legend had yet another surgery -- this time after he revealed he's been diagnosed with prostate cancer.
The former wrestler and his family spelled everything out on his social media page this week ... announcing in a video on Thursday that doctors had recently found cancer in his body.
"It's been going on for a couple months now," Duggan said, "and [my wife] Debra and I have been living with it and getting ready, but reality is here.