U.S. Sen. John McCain has been diagnosed with a brain tumor, according to statements released Wednesday from the Mayo Clinic and his office.

"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 Mayo Clinic said. "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.

"The Senator and his family are reviewing further treatment options with his Mayo Clinic care team. Treatment options may include a combination of chemotherapy and radiation.

"The Senator's doctors say he is recovering from his surgery amazingly well and his underlying health is excellent."

In a separate release McCain's office said:

"Senator McCain appreciates the outpouring of support he has received over the last few days. 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."

Mitch McConnell, the Senate Majority Leader, also issued a statement on Wednesday:

"John McCain is a hero to our Conference and a hero to our country. He has never shied from a fight and I know that he will face this challenge with the same extraordinary courage that has characterized his life.

The entire Senate family's prayers are with John, Cindy and his family, his staff, and the people of Arizona he represents so well.

This is a developing story.