Transcript for Cameron Mathison reveals he has serious tumor on his kidney
We have to move on to our cover story. An exclusive with a dear friend of our, Cameron Mathison, the actor, TV host, former "Gma" contributor revealing he has a tumor on his kidney and is set to undergo surgery tomorrow. Kayna Whitworth had a good chance to sit down with cam. Good morning, kayna. Reporter: Hey, robin, good morning. So Cameron spent years insisting that something was wrong and finally demanding they do an mri and that's when doctors found the tumor in his kidney that's consistent with renal cell carcinoma. He's been a soap opera star. I love you. Reporter: A fan favorite on "Dancing with the stars." And a "Gma" contributor too. And this morning, the actor and TV host Cameron Mathison is in the battle of his life. I just felt like something was wrong. It just wasn't quite right. Reporter: The 50-year-old opening up on the set of his show "Home and family" sharing his recent health scare. The radiology report said that there is a 4.2-centimeter mass on the right kidney that is consistent with renal cell carcinoma and I'm just standing there and thinking to myself, I know this is just one of those dreams. I know I'm about to wake up. Like I really was genuinely trying to make myself wake up from that moment thinking that this is just so surreal. What was the first thing you thought about? My kids. Yeah. I called my wife. That was tough because at that time also I didn't know anything. I didn't know if this was a death sentence. I didn't know if it had spread. I knew from the radiology report it hadn't gone to my lymph nodes but I didn't now much more than What did she say to you. First thing out of her mouth which is amazing to me is we got this. We're going to beat it like right away. First thing out of her mouth and she just went into, you know, supportive mode and strong mode and being there for me. He says he spent years with specialists trying to figure out why he was having such pain and cramping in his abdomen. I was convinced that people thought I was a hypo-condrey yak and nuts. I've been at this for so long. Reporter: His consistent discomfort motivating him to demand an mri and that's when doctors found the tumor. It was about four hours later. I got a call, I saw my doctor's number come up on my phone and I'm line, this isn't good. Reporter: The doctors also telling Mathison they believe the tumor has gun growing inside his kidney for the last ten years and crediting his healthy lifestyle for keeping the tumor so small. This has been in me minimum, minimum ten years. Minimum of ten years. Likely longer. I don't drink. I eatncredibly healthy. I eat a low sugar low carbohydrate diet. The things that likely in our best guess have helped it from spreading and growing even quicker. Reporter: Always maintaining a positive attitude Mathison is scheduled for surgery tomorrow. Are you going to have to be in the hospital -- Two or three days they say. Might be losing an organ. That requires -- I was like, really. Do I have to stay a couple they're like we might be taking the kidney out of your body. Reporter: Now he's telling everyone to take control of their own health. I think keeping positive through this even when I didn't know what was going on and I wonder if that helps. It feels like to M it does. His positive attitude is absolutely infectious. Cameron says it's important for all of us to advocate for our own health. Nobody knows your body like you do. Had he not been so insistent that tumor would have kept growing and he says likely would have gone undetected until it spread to other organs, bone or muscle. Robin. Oh, goodness. Kayna, thank you very much and Dr. Jennifer Ashton joins us now. We're glad he found it. Absolutely. And how he advocate the for what are the symptoms? Renal cell carcinoma is a tumor that starts in the cell's lining, the tubes of the kidney. We continental make that diagnosis until the pathologist has looked at the tissue so it's actually made after the surgery but likely that's what it is and it can be difficult to diagnose. It's one of those cancers that can make diagnosis difficult. The typical signs of it, however, if you see blood in the urine, if you see low back pain especially on one side. We call it flank pain or feel a lump or mass in the lower back and nonspecific findings of fatigue, loss of appetite, weight loss, of course, people can have these symptoms and not have cancer. That's what makes it difficult because, listen, from the doctor's standpoint people don't walk in with a sign always that says, I have cancer, it can be difficult to make a diagnosis. Who's most at risk? You know, we don't totally understand what puts people at risk for renal cell carcinoma. Age is a big one. It is more common in men versus women. People who smoke, who are obese, certain workplace chemical exposures like asbestos or benzene and certain medications, sometimes people treated for one condition, that medication or treatment can actually predispose you to this. The fact that Cameron, he knew. So from a medical standpoint how can we advocate for ourselves? Echoing their statements, trust your body. No one knows your body better than you. It's important when people hear this to understand we have a systemic check list when we are trying to evaluate or work up or make a diagnosis. Even if we wanted to, doctors can't say, right to mri. Insurance companies will not let us. They will block that order and we have to get on and justify it and they will decline it. So, unfortunately, it's not always possible to go right to the most aggressive step. There's cost involved. Risk, benefits, but, again, the key point is making that diagnosis as promptly as possible because as we know when we talk about cancer, early treatment generally gives the best outcome. Got to be persistent. We wish him well. He is one of the nicest guys. We loved it when he was here. Michael. Thank you so much.
This transcript has been automatically generated and may not be 100% accurate.