WASHINGTON, D.C. — John McCain (R-Arizona) has been diagnosed with brain cancer following a procedure to remove a blood clot above his left eye, his office announced on Wednesday.

A primary brain tumor — known as a glioblastoma — was discovered during tissue pathology after he had the procedure.

His office noted that McCain’s doctors said he is recovering “amazingly well,” and that his “underlying health is excellent.”

McCain may undergo chemotherapy and radiation treatments.

“The Senator and his family are reviewing further treatment options with his Mayo Clinic care team,” said the statement.

McCain, 80, was the Republican nominee for president in 2008. He was first elected to the Senate in 1986.

His daughter, Meghan McCain, said in a Twitter post that “the news of my father’s illness has affected every one of us in the McCain family. My grandmother, mother, brothers, sister and I have all endured the shock of the news, and now we live with the anxiety about what comes next.”

She added, “It won’t surprise you to learn that in all this, the one of us who is most confident and calm is my father. He is the toughest person I know.”

Many of McCain’s colleagues in the Senate tweeted out prayers and words of support and praise. A former colleague, Hillary Clinton, said that McCain was “as tough as they come.”

President Trump said in a statement, “Senator John McCain has always been a fighter.  Melania and I send our thoughts and prayers to Senator McCain, Cindy, and their entire family.  Get well soon.”

Former president Barack Obama called McCain “an American hero & one of the bravest fighters I’ve ever known.”