Sen. John McCain is said to be recovering at home following surgery Friday to remove a blood clot from above his left eye, but there are concerns about the cause of the 80-year-old Arizona senator's clot.
"Senator McCain received excellent treatment at Mayo Clinic Hospital in Phoenix, and appreciates the tremendous professionalism and care by its doctors and staff. He is in good spirits and recovering comfortably at home with his family," McCain's office said. "On the advice of his doctors, Senator McCain will be recovering in Arizona next week."
During the minimally-invasive surgical procedure, called a craniotomy, doctors made a small incision over the eyebrow to access a part of the left frontal lobe of the brain.
Doctors reportedly removed a five-centimeter blood clot above his left eye.
It has not been disclosed whether McCain had symptoms that led doctors to look for the clot. Symptoms can include speech problems, muscle weakness or even seizures.
Age can be a contributing factor to this type of clot in the brain, known as a subdural hematoma.
In June, his somewhat confused questioning of James B. Comey, the former F.B.I. director, led to concerns about his mental status, which he later jokingly dismissed by saying he had stayed up too late watching baseball the night before.
Although unfamiliar with the specifics of McCain's situation, an expert from University Hospitals in Cleveland says the senator's history of invasive melanoma, a clot in the brain could signal a recurrence.
"So melanoma is a type of cancer that very commonly goes to the brain and those types of tumors also have a high likelihood of bleeding," said Dr. Michael DeGeorgia, director of neuro critical care center at University Hospitals. "So it is possible, and we don't know this of course, but it is possible that this little bit of bleeding represented bleeding into a metastatic melanoma and that through that key-hole craniotomy, they took out some of the blood and sent tissue to the lab, to the pathologist."
The Mayo Clinic Hospital said pathology reports for McCain should come back within several days.
"The Senator is resting comfortably at home and is in good condition. His Mayo Clinic doctors report that the surgery went 'very well' and he is in good spirits," the Mayo Clinic said. "Once the pathology information is available, further care will be discussed between doctors and the family."
Senate Majority Leader Mitch McConnell says he has spoken to ailing McCain on Monday morning and wished him a speedy recovery. He called the Arizona Republican a "tough guy."
McConnell says he hopes McCain will be back in the Senate soon. Over the weekend the Republican leader delayed a vote on the GOP health care bill. McCain's absence has left Republicans short of the votes necessary to move ahead on the legislation to erase much of Barack Obama's health care law.