Correction: Earlier versions of this article misstated when Gov. Larry Hogan discovered the lump in his neck that led to his cancer diagnosis. He found the lump while on a trade mission to Asia, a day before leaving to return to the United States. The article has been corrected.

An emotional Maryland Gov. Larry Hogan disclosed Monday that he has been diagnosed with late stage 3 non-Hodgkin’s lymphoma, which he called “a very advanced and very aggressive” form of cancer.

At a hastily called news conference that felt more like an intimate family meeting, the 59-year-old Republican described the disease as a hurdle that he plans to surmount.

“I’m going to face this challenge with the same energy and determination that I’ve relied on to climb every hill and to overcome every obstacle that I’ve faced in my life,” said Hogan, who was sworn into office in January after winning an upset victory over then-Lt. Gov. Anthony G. Brown (D).

He said that he will soon begin an 18-week chemotherapy regimen that will begin with four days in the hospital, in the intensive care unit. The governor said he will rely on Lt. Gov. Boyd K. Rutherford to fill in for him on state business and to make decisions for him when necessary — an arrangement that was put in place at least once, when Hogan was under anesthesia for an hour and Rutherford was standing by in case of emergency.

Maryland Gov. Larry Hogan (R) has "advanced" non-Hodgkin’s lymphoma and will soon begin aggressive chemotherapy treatments. (WUSA9)

“Luckily there was no major decision during that one hour I was asleep, so [the] lieutenant governor, he didn’t make any crazy decisions,” Hogan said. “But he has my utmost confidence.”

Hogan said he has no plans to leave office. He vowed to continue trying to advance his agenda, which includes strengthening Maryland’s economy and business climate, cutting taxes, overseeing efforts in Baltimore to recover from recent rioting and deciding whether to push forward with long-planned light-rail projects.

“Most likely, I’m going to lose my hair — you won’t have these beautiful gray locks. I may trim down a little bit. But I won’t stop working to change Maryland for the better,” he said, a slight tremor in his voice. “I’ll be working hard and making the decisions that the people of this state elected me to make.”

The average-guy persona that helped Hogan win over voters in November, when he was a relatively little-known businessman competing against a two-term lieutenant governor, was on full display Monday afternoon.

He gripped the lectern and spoke openly, saying that he had noticed a lump in his neck while shaving, and that it turned out to be one of more than 30 tumors. He struggled while listing the medical terms: “An aggressive B-cell, non-Hodgkin’s lymphoma, to be specific.” To his left, his wife, Yumi Hogan, clenched her hands into fists.

Kevin Cullen, director of the University of Maryland Marlene and Stewart Greenebaum Cancer Center, said that about 70 percent of patients with non-Hodgkin’s lymphoma are still alive after five years.

Maryland Gov. Larry Hogan (R) announced he has "very advanced and very aggressive" non-Hodgkin's lymphoma. Here's what you need to know about this type of cancer, its survival rate and treatment options. (McKenna Ewen and Gillian Brockell/The Washington Post)

Cullen said most cases of the disease are discovered at stage 3, when the tumors are more pronounced, just as Hogan’s was. Patients rarely require surgery or radiation in addition to chemotherapy, he said, adding that he thinks Hogan is taking the right approach with his plans to work while being treated.

“We encourage people to maintain as normal a routine as possible when they’re being treated,” Cullen said. “I think it’s important for people to maintain a positive psychological outlook. People who derive pleasure and mental stimulation from working, we encourage them to do it.”

The Maryland Constitution allows for the lieutenant governor to serve as acting governor “when notified in writing by the Governor that the Governor will be temporarily unable to perform the duties of his office.” It also states that “when a vacancy occurs in the office of Governor, the Lieutenant Governor shall succeed to that office for the remainder of the term.”

In classic Hogan style, the governor tried to lighten the mood on Monday, even as members of the Cabinet and his relatives sometimes fought tears.

He joked that he has a better chance of beating cancer than he did of triumphing over Brown — and that he’s such a workaholic that even if he is at his desk only part-time in the coming months, he will still be working harder than most governors.

Hogan said tests have shown that the cancer has spread through his abdominal core and is “pressing up against my spinal column.” Even so, he said, he feels healthy and energetic most of the time. “There’s a very strong chance of success,” Hogan said of his treatment. “Not only a strong chance of survival, but a strong chance of beating it altogether.”

The governor said he discovered the lump while on a trade mission to Asia, a day before he was scheduled to head home to the United States. Since his return on June 6, he missed numerous meetings to undergo medical tests and receive his diagnosis. He said he now realizes that a cough and some back pain he felt during the trip was related to his tumors.

Since taking office five months ago, Hogan has faced down Democratic legislative leaders in a bitter budget battle that focused on education and pension spending; fought, with mixed success, to push his maiden legislative package through the Democratic-controlled General Assembly; declared a state of emergency in Baltimore after unrest related to the fatal injury of Freddie Gray in police custody; and moved his base of operations to the city from Annapolis while the emergency was in effect.

Although this is his first time in elected office, Hogan has been immersed in politics his entire life. His father, Lawrence J. Hogan Sr., represented Maryland in the U.S. House from 1969 to 1975 and was then the last Republican to serve as Prince George’s County executive.

Soon after graduating from Florida State University, the younger Hogan worked for his father’s administration and then went into real estate. He served as appointments secretary in the administration of Gov. Robert L. Ehrlich Jr. (R).

For most of his life, Hogan was a work-obsessed bachelor. But in his 40s, he went to an art show and met Yumi, an artist from South Korea who was divorced and had three daughters.

The two married in 2004, and the girls came to consider Hogan a father figure. He refers to them as his daughters. Two of the three were at the news conference on Monday, along with their husbands and the Hogans’ 2-year-old granddaughter, her hair in pigtails.

Hogan has said that his wife taught him that there’s more to life than work. While he was campaigning, she was frequently at his side, supporting him but also reminding him to take an occasional break.

In 2011, Hogan began Change Maryland, a grass-roots organization that criticized then-Gov. Martin O’Malley (D) for raising taxes and not doing enough to stimulate economic growth.

Hogan’s gubernatorial bid was considered a long shot: Registered Democrats outnumber Republicans by more than 2 to 1 in Maryland, and Brown had spent eight years in statewide office and had millions more dollars to spend.

But while Brown kept a low profile on the campaign trail, Hogan crisscrossed the state in a black coach bus he dubbed the “Change Maryland Express.” He wore jeans and polo shirts, posed with farm animals at county fairs, jogged along parade routes, and talked to voters about their family finances and frustrations.

His eventual win was called one of the biggest upsets of 2014. His 86-year-old father was with him at his swearing-in.

After Hogan received his diagnosis late last week, he called several members of his senior staff to his office on Saturday to matter-of-factly share the news. They knew something was wrong because of the canceled meetings. But they weren’t expecting something like this.

Throughout the weekend, Hogan slowly told relatives, close friends and a few more aides. He spent Father’s Day with his father, wife, daughters, sons-in-law and granddaughter.

He told his staff that he wanted to hold a news conference on Monday, even though his doctors were asking him to wait. He did not want news of his illness to leak out. Just before the news conference, he called his Cabinet members together and shared the news with them.

Hogan insisted on taking questions from reporters after he spoke, and joked with his staff beforehand that someone probably would ask about the controversial Baltimore Red Line and suburban Washington Purple Line projects.

Nobody did.