Former NBA player Jason Collins has been diagnosed with stage IV brain cancer. "A few months ago, my family released a short statement saying I had a brain tumor. It was simple, but intentionally vague," Collins, 47, wrote in an essay for ESPN published on Thursday, December 11. "They did that to protect my privacy while I was mentally unable to speak for myself, and my loved ones were trying to understand what we were dealing with. But now it's time for people to hear directly from me." The former Washington Wizards center continued, "I have Stage 4 glioblastoma, one of the deadliest forms of brain cancer. It came on incredibly fast." NBA's Nikola Topic Begins Chemotherapy After Testicular Cancer Diagnosis Collins, who was the first openly gay player in NBA history, explained that his symptoms began a few months after he married husband Brunson Green in May. He and Green, 58, were supposed to attend the U.S. Open in August, but they missed their flight because Collins was unable to focus on packing. "I had been having weird symptoms like this for a week or two, but unless something is really wrong, I'm going to push through. I'm an athlete," he noted. When Collins had a CT scan at UCLA, the tech quickly told him he needed to see a specialist. "According to my family, in hours, my mental clarity, short-term memory and comprehension disappeared - turning into an NBA player's version of 'Dory' from 'Finding Nemo.' Over the next few weeks we would find out just how bad it was," he wrote. "What makes glioblastoma so dangerous is that it grows within a very finite, contained space - the skull - and it's very aggressive and can expand. What makes it so difficult to treat in my case is that it's surrounded by the brain and is encroaching upon the frontal lobe - which is what makes you, 'you.'" Kevin Winter/Getty Images for Sports Spectacular Collins compared his cancer to a "monster with tentacles spreading across the underside of my brain the width of a baseball." Without aggressive treatment, he said he would "probably be dead within six weeks to three months." Collins also detailed his experience with taking an anti-cancer drug and going through radiation, which helped him emerge from his "fog" and regain the ability to walk. He expressed his determination to beat his glioblastoma, no matter what it takes. "We aren't going to sit back and let this cancer kill me without giving it a hell of a fight," Collins wrote. "We're going to try to hit it first, in ways it's never been hit: with radiation and chemotherapy and immunotherapy that's still being studied but offers the most promising frontier of cancer treatment for this type of cancer." He continued, "The average prognosis is only 11 to 14 months. If that's all the time I have left, I'd rather spend it trying a course of treatment that might one day be a new standard of care for everyone." SportsCenter's Jay Harris Announces Cancer Diagnosis, Undergoing Surgery Collins' family announced his treatment for a brain tumor in September. "NBA Ambassador and 13-year NBA veteran Jason Collins is currently undergoing treatment for a brain tumor," they said in a statement at the time. "Jason and his family welcome your support and prayers and kindly ask for privacy as they dedicate their attention to Jason's health and well-being." The Houston Rockets drafted Collins with the 18th overall pick in the 2001 NBA Draft before he was traded to the then-New Jersey Nets. He played for the Nets until 2008 before moving on to the Memphis Grizzlies. Collins also played for the Minnesota Timberwolves, Atlanta Hawks, Boston Celtics and Washington Wizards. He closed out his basketball career with the Brooklyn Nets in 2014.