Arizona Senator John McCain is battling brain cancer.  

The 80-year-old was diagnosed with the disease after surgery addressing a blood clot above his left eye. 

The Mayo Clinic in Phoenix released a statement saying tissue pathology revealed a malignant tumor associated with the blood clot.  

McCain and his family are reviewing treatment options, which could include chemotherapy and radiation.  

Senator McCain's office says he's in good spirits and still recovering from the surgery in Arizona. 

McCain has served as Arizona's senator since 1987.  He was the Republican presidential nominee in 2008.