By JOHN McCLAIN HOUSTON CHRONICLE Texans outside linebacker Brian Cushing denied that he took hCG and insisted he had no idea how enough of the substance got into his body to cause him to test positive for violating the NFL's policy against performance-enhancing drugs. 'I want to make it known that I did not inject or ingest any illegal substances that would enhance my performance,' Cushing said Thursday at a news conference at Reliant Stadium. 'The question of how it got into my body is still unclear. 'It's something I'm very concerned about, just the fact of how it's there and what's going to deter it from happening again. And that's something that we're going to have to medically investigate.' Cushing, who has been dogged by steroid accusations since high school, was suspended for the first four games of the 2010 season for testing positive for hCG (human chorionic gonadotropin). The substance is most commonly found in the urine of pregnant women but also can be produced in the pituitary gland in men and women. The most controversial use of hCG as a drug is as a masking agent for steroids. It enhances production of testosterone in the body during or after a cycle of steroid use. The substance often is injected but is also available in a nasal spray and in a topical cream. 'There's going to be certain tests that are going to be performed and certain things that we need to do,' Cushing said. The Texans, who said they would have no comment on Cushing after the news conference, made him available to the media on a one-time basis to discuss his positive test and suspension. He is able to participate in all team activities, including the start of organized team activities Monday, until he begins to serve his suspension before the regular-season opener against Indianapolis. Cushing was randomly tested by the NFL in September. He was informed of the positive test in October and appealed. His suspension was announced May 7. 'When everything first came out, I was completely unfamiliar with hCG,' he said. 'I was told that the only way it can get into your body, and, obviously, everyone having their different opinions, was that it was either through injection or through a tumor. 'I know that I didn't ingest or inject anything. I played the whole season thinking I had tumors, (that) this could not only be my last season but my last year.' After getting the letter in October from the independent doctor in Ohio that he had tested positive, Cushing had five days to file his appeal. Cushing, his family and agent Tom Condon were the only ones who knew he had tested positive and had appealed. Condon said Thursday that Cushing underwent his first 'battery of tests' in November. Condon said Cushing has subsequently undergone more tests in Houston, San Diego and Denver. 'He was tested for a variety of things that were recommended by his (personal) doctor,' Condon said. 'My understanding is they're going to do it again. They're going to take him from head to toe and repeat everything.' A person close to Cushing said he underwent tests that turned up negative for testicular cancer. 'Right now, I'm concerned about my health,' Cushing said. 'I have to take care of my situation and find out why this is happening from a health standpoint and also from a prevention standpoint.' Dr. Christopher Wood, a professor of urology at the University of Texas M.D. Anderson Cancer Center, confirmed that two types of tumors associated with testicular cancer -- one very common, one less common -- secrete levels of hCG that would show up in drug testing. Asked if that meant Cushing's claim was plausible, Wood said 'yes and no.' 'It would be surprising for someone who tested positive in October not to have felt some sort of abnormal mass in his testicles,' said Wood. Wood also noted that the more common type of testicular tumor that secretes hCG can be very aggressive. He said when it is advanced, it can secrete very high levels of hCG. Cushing thought he would win his appeal. 'I was stunned basically because of the scientific and medical data that we had backing it up,' he said. 'I felt that knowing that I did not ingest or inject anything at all, the fact that how this got into my body, why this was taking place -- that's why I was confused.' Cushing knows there's nothing he can do about his reputation as a steroid abuser. 'Any time something like this (happens), people will say, 'I told you so,' or, 'There it is,' and it's unfortunate,' he said. 'But you look at the college track record -- there's nothing there. You look at the rest of the season -- there's nothing there. 'And it's just the fact that there's one kind of certain thing in there that it's such a low level that it wouldn't even be performance-enhancing.' The Chronicle's Todd Ackermann contributed to this report. john.mcclain@chron.com XXX - End of Story3D 