Breaking: Sen. John McCain diagnosed with brain cancer

Senator John McCain (R-Ariz.) has been diagnosed with brain cancer, his office revealed Wednesday. The cancerous brain tumor was discovered while he underwent surgery to remove a brain clot.

The Mayo Clinic released a statement at the request of the McCain family.

"On Friday, July 14, Sen. John McCain underwent a procedure to remove a blood clot from above his left eye at Mayo Clinic Hospital in Phoenix," the statement read. "Subsequent tissue pathology revealed that a primary brain tumor known as a glioblastoma was associated with the blood clot."

"Scanning done since the procedure (a minimally invasive craniotomy with an eyebrow incision) shows that the tissue of concern was completely resected by imaging criteria," it continued.

"Treatment options may include a combination of chemotherapy and radiation," it added. "The Senator's doctors say he is recovering from his surgery 'amazingly well' and his underlying health is excellent."

McCain's office also released a statement thanking his doctors.

"Senator McCain appreciates the outpouring of support he has received over the last few days," it read. "He is in good spirits as he continues to recover at home with his family in Arizona. He is grateful to the doctors and staff at Mayo Clinic for their outstanding care, and is confident that any future treatment will be effective. Further consultations with Senator McCain's Mayo Clinic care team will indicate when he will return to the United States Senate."

His daughter, Meghan McCain, released a statement from her Twitter account. "The news of my father's illness has affected every one of us in the McCain family. My grandmother, mother, brothers, sisters and I have all endured the shock of the news," she wrote.

"My love for my father is boundless, and like any daughter, I cannot and do not wish to be in a world without him," she added. "I have faith that those days remain far away. Yet even in this moment, my fears for him are overwhelmed by one thing above all: gratitude for our years together, and the years still to come."

"He is a warrior at dusk," she concluded, "one of the greatest Americans of our age, and the worthy heir to his father's and grandfather's name. But to me he is something more. he is my strength, my example, my refuge, my confidante, my teacher, my rock, my hero - my dad."

McCain's surgery had postponed the vote on the Senate Republicans' Obamacare repeal and replace bill, which later failed to garner the necessary votes.