BOSTON -- Surrounded by his wife and children, Sen. Edward M. Kennedy left Massachusetts General Hospital smiling, waving and giving a thumbs up Wednesday morning as he headed south to his home on Cape Cod.

A small bandage could be seen on the back of Kennedy's head where the biopsy was performed that led to his diagnosis Tuesday of malignant brain cancer.

As a crowd of well-wishers applauded, Kennedy, 76, kissed and hugged his daughter Kara and son Patrick as well as his niece Caroline, then gave his dogs a pat before boarding a black SUV for the ride south to the Cape.

"It was a pleasant surprise and it was nice to see the human interaction. It was nice to see the crowd of people standing here who just applauded with great appreciation," Bob Sweet, of New Hampshire, said.

"We (applaud) for our baseball teams. We go to airports, we go to places for the Red Sox and the Patriots and winning teams, you know. He deserved that," Jean Rohde said.

"The Kennedys have been part of the community or the Boston landscape for such a long time that it's kind of sad that something might come to an end," hospital worker Sean Butler said.

"They're just such an important family in U.S. history and he's the last brother alive. You hate to see anything happen to him. You don't want to say it's an end of an era, but he is the last surviving Kennedy," Sue Ann Wall said.

The state's senior senator has been at Massachusetts General Hospital since Saturday after suffering a seizure. He remained there until the doctors diagnosed that he has a malignant glioma in his left parietal lobe Tuesday afternoon.

He headed home to the family's Hyannis Port compound to rest over the Memorial Day holiday weekend while his doctors determine the best treatment plan for his cancer. As soon as he got there he took a walk on the beach with his dogs.

"Sen. Kennedy has recovered remarkably quickly from his Monday procedure and therefore will be released from the hospital today ahead of schedule. He will return to his home on Cape Cod while we await further test results and determine treatment plans. He's feeling well and eager to get started," Kennedy's doctors, Dr. Lee Schwamm, a top neurologist at Massachusetts General, and Dr. Larry Ronan, Kennedy's primary care physician, said in a prepared statement Wednesday.

His wife, Vicki, released a statement earlier saying his family was as stunned by the news of his brain cancer as the rest of the nation.

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"I have to be honest; we've been pitched a real curveball," she said in a letter released to the public. "Rest assured, this is only the first inning. We're gathering experts, and getting multiple opinions and the best advice we can. Teddy is leading us all, as usual, with his calm approach to getting the best information possible."

Kennedy learned Tuesday that he has a malignant cancerous tumor in a section of the brain that governs sensation and plays a role in movement and language.

His wife said the family is grateful for all the support it has received from the public.

"We've heard from so many of you and wanted you to know how very much it means to us. We are grateful for your prayers, support and friendship as we deal with this unexpected news," she wrote.

"We hope you understand if we don't respond to all your calls and notes right now as we figure this whole thing out. But, please know that they are an enormous source of comfort."

Kennedy's son, Patrick, a Rhode Island congressman, released a statement through a spokeswoman who said, "He's comforted by the fact that his dad is such a fighter, and if anyone can get through something as challenging as this, it would be his father. ... He's hopeful that his father is going to beat this and be back at it. This is definitely a medical challenge that his dad can get through."

"The usual course of treatment includes combinations of various forms of radiation and chemotherapy. Decisions regarding the best course of treatment for Sen. Kennedy will be determined after further testing and analysis," his MGH doctors said in a statement released Tuesday afternoon.

Kennedy's wife and children gathered around the patriarch of the powerful Democratic party clan after he learned of the news.

Many of his colleagues and constituents were stunned upon learning that Kennedy has what doctors call an "aggressive" form of cancer that is often fatal.

"It's not a good cancer. It's a fast-growing cancer," ABC News medical editor Dr. Tim Johnson said.

Johnson said the most common therapy for the cancer Kennedy has is a combination of chemotherapy and radiation that lasts for about six weeks, during which many patients can function "fairly well."

In the long run, however, the prognosis for the kind of cancer Kennedy has is not good, many doctors agreed.

"Overall, for this type of cancer, the survival is typically between one and two years. Kennedy is a fighter. We know that. So, that will be a factor in the outcome," Johnson said.

Many surgeons said it was unlikely that surgery would be considered as a treatment option.

"There are two reasons not to do surgery. One, the tumor is too big. Or it's located in a critical location and this is a critical location," Johnson said.

Word of Kennedy's cancer rocked Capitol Hill, where Kennedy, first elected in 1962, has spent more than four decades in Congress. Both Republicans and Democrats were united in their concern for the senator. Virginia Sen. Robert Byrd, 90, the longest-serving Senator in the nation, wept on the Senate floor.

"Ted, Ted. My dear friend. I love you and I miss you," Byrd said, weeping.

"He's a strong guy and has great heart and we're confident he's going to be back here," Connecticut Sen. Chris Dodd said.

"Everybody needs to pull for him and his family and remember that this guy is one unbelievable fighter," Massachusetts Sen. John Kerry said.

On Beacon Hill, Gov. Deval Patrick said he had been in touch with the Kennedy family.

"I know I speak for people all over the commonwealth, indeed, all over the country, in wishing him well and sending him the very best and strongest prayers for his comfort and his recovery," Patrick said.

At the family's Cape Cod compound in Hyannisport, Mass., residents said they couldn't believe the news.

"I think if he can't go back into the Senate, he will be greatly missed because he is such an impact on the whole state," one woman said.

"My heart goes out to that family because that's just an awful thing to find out," another said.