Glioblastoma multiforme -- the type of tumor that U.S. Sen. John McCain, R–Ariz., has been diagnosed with -- is an aggressive form of brain cancer that is rare and typically occurs in adults. According to the American Brain Tumor Association, there are about 12,390 new cases a year in the U.S.McCain had undergone surgery last week to remove a blood clot from above his left eye. Doctors at the Mayo Clinic in Phoenix said the clot was an indicator that the tumor started to grow. McCain’s doctors managed to remove all of the tumor that was visible on the brain scans, but surgery is hardly ever enough. McCain is a long-term survivor of melanoma but doctors classified this new cancer as a "primary tumor," meaning it's not related to his former malignancies.

Source: Fox News July 20, 2017 04:26 UTC