Dave Coulier announced exclusively on the TODAY show that he’s been diagnosed with Stage 3 non-Hodgkin lymphoma, a type of blood cancer that starts in the lymphatic system.

The “Fuller House” star, who famously played Uncle Joey, noticed his first symptoms a little over a month ago, when he came down with a cold. In the past, he’d noticed the lymph nodes in his neck or armpits would swell when he was sick. This time, though, he felt surprised to discover a golf-ball sized lump in his groin within a week of falling ill.

“It swelled up immediately,” Coulier, 65, tells TODAY.com in a phone interview. “I thought, ‘Wow, I’m either really sick, or my body’s really reacting to something.’”

Worried, he visited his doctors who ran a variety of tests, including bloodwork, EKG, and PET and CT scans. While everything appeared to be normal, the doctors biopsied the lymph node just to be safe. Coulier soon learned why his lymph node became so enlarged.

“(My doctors) said, ‘Hey, we wish we had better news, but you have non-Hodgkin lymphoma, B-cell lymphoma,’” Coulier recalls. “It was a shock.”

Despite his cancer diagnosis, Coulier is still finding joy in life.

“My joke is that in four short weeks I’ve gone from a Virgo to a Cancer,” he says. “I’ve tried to retain a sense of reality but also a sense of humor about it.”

Dave Coulier diagnosed with Stage 3 non-Hodgkin lymphoma

When Coulier felt under the weather a little over a month ago and noticed a swollen lymph node in his groin, he felt puzzled.

“The onset of this growing lymphoma in my groin area was very quick. So I said, ‘Something’s not right,'” he recalled to Hoda during his Nov. 13 appearance on TODAY.

Coulier visited his doctor, who ordered a battery of tests.

“They said, ‘Yeah, we need to take a serious look at this.’ And so, we did blood tests,” he says. “Blood tests came back great. My EKG, everything great. Heart, everything perfect.”

But his doctors felt worried by how quickly the lump grew and ordered more advanced imaging before eventually wanting a sample of it for testing.

“‘We’d like to either remove this or biopsy it,’” Coulier recalls his doctors telling him. “I said, ‘Well, why don’t we just remove it and biopsy it at the same time?’”

Three days later, Coulier received the news from his doctor that he had B-cell lymphoma, a type of cancer that develops in B-lymphocytes, according to the American Cancer Society. B-cell lymphomas account for the vast majority of non-Hodgkin lymphomas. Every year, more than 80,000 Americans are diagnosed with non-Hodgkin lymphoma.

“The first thing I said to them was, ‘Wait a minute — cancer?’” he Coulier. “(I was) feeling like I got punched in the stomach because it never happens to you. You always hear about it happening to someone else.”

Hearing the news was even harder because his wife, Melissa Coulier, wasn’t at home.

“I was just contemplating, ‘How do I tell her?’” he says. “When I told her, of course, she thought I was joking.”

After he reassured her that he was not joking, Melissa “organized (his) entire life, from nutrition to the doctor’s appointments to the pills.”

“She’s got stuff color-coded,” he says. “It’s pretty great.”

To understand what stage of cancer he had, Coulier’s doctors took a bone marrow sample.

“They wanted to see if (the cancer had) moved on to any major organs or my blood or bones or anything,” he says. “That was pins and needles for a few days because I didn’t know what stage it was or if it had progressed.”

Yet at some point, Coulier started feeling a sort of acceptance.

“I told Melissa I don’t know why, but I (am) OK with whatever the news (is) going to be no matter how devastating. … I can’t explain where that came from,” he says. “I’ve had an incredible life. I’ve had the most amazing people in my life. This has been an extraordinary journey, and I’m OK if this is the end of the journey.”

A few days later, he learned he had Stage 3 non-Hodgkin lymphoma.

Stage 3 non-Hodgkin lymphoma survival rate

Stage 3 non-Hodgkin lymphoma means the cancer has not spread outside the lymphatic system, according to the American Cancer Society. The five-year survival rate for B-cell non-Hodgkin lymphoma that has not spread widely is about 74%, per ACS.

“(Stage 3) doesn’t sound great,” Coulier says, but because it hasn’t spread to his bone marrow, doctors told him his curability rate is upwards of 90%.

“It’s very treatable,” he said on TODAY.

Starting chemotherapy

Doctors wanted Coulier to start chemotherapy promptly, and he underwent another surgery to have his chemotherapy port, which delivers the medication, placed.

Leading up to his first treatment, Coulier faced his fear of the unknowns of cancer.

“You hear chemo, and it scares the daylights out of you,” he says. “The first round was pretty intense because you don’t know what to expect. You don’t know how you’re going to feel. Is this going to hit me immediately? Is it going to be devastating? Am I going to walk out of here?”

He felt better than expected after his first round of chemotherapy. In total, he’ll have six rounds every 21 days and should be finished with treatment by February 2025. Following treatment, he expects a “total remission.”

“It’s been a bit of a roller coaster. There (are) days where I feel unbelievable,” he says. “Then there’s other days where … I’m just going to lay down and let this be what it’s going to be.”