Sen. John McCain has been diagnosed with cancer. The Mayo Clinic in Phoenix confirms McCain has a brain tumor.

The tumor was discovered after McCain underwent a procedure to remove a blood clot from above his left eye last week at the Mayo Clinic Hospital in Phoenix. The tumor, known as a glioblastoma, was associated with the clot.

Mayo Clinic says the senator and his family are reviewing their treatment options, which may include a combination of chemotherapy and radiation. 

McCain’s office says the senator is in good spirits and is consulting with doctors about when he can return to the Senate.

On Twitter, his daughter Meghan McCain wrote that cancer may affect her dad in many ways, but, "it will not make him surrender. Nothing ever has."