Mark Wright has had a 12cm tumour removed from his armpit.
The former The Only Way Is Essex star, 34, shared a lengthy post on Instagram explaining how he had an operation on Wednesday following a series of consultations.
The reality TV star, who was an original cast member on the ITV show, said he had wanted to speak openly about the issue to encourage others to get checked.
He also shared a series of photos showing himself in the operating theatre and the tumour itself after being removed.
Wright wrote: “Ok, it’s been a tough call whether or not to speak about this.
“One part of me wants to keep something like this private and the other part is thinking, if I can help/potentially save 1 person, well…. this is the right thing to do.
“So here goes. I discovered a lump in my breast/armpit area. Not very big, but enough to cause concern and to be cautious enough to get it checked.
“After some time the lump grew and began to bother me. I am someone that when it comes to life in general, I leave no stone unturned. When it involves health, this idiom quadruples.”
Wright said he saw another specialist, a breast consultant, for a second opinion and had an MRI scan before seeing a sarcoma specialist.
“This specialist saw the scans around 10 days ago and today I was in theatre having this little git removed,” he said.
“His fast and incredible turn around was due to the fact he did not want to leave it any longer and wanted it out to prevent the rare risk of a LIPOMA turning into a sarcoma overtime.
“He also could not 100% confirm by the MRI that this was definitely a benign tumour and not something more sinister.”
Wright, who is married to actress Michelle Keegan, said the tumour would be sent off for further testing.
He added: “MORAL OF THE STORY: If you notice anything that doesn’t look or feel quite right. Don’t leave it.
“Nothing in life is more important than your health and well-being. Get checked, check yourself and make sure you take good care of yourself.”