July 29, 2012 -- World Wrestling Entertainment star Dalip Singh, better known by his ring name The Great Khali, underwent surgery Wednesday to remove a tumor that caused his huge size.

At 7-foot-1 and weighing 347 pounds, Singh, a former police officer in India's Punjab province, made his WWE debut in 2006, and won the World Heavyweight Championship belt just a year later. But while his dimensions have earned him celebrity status, they are the result of a tumor that likely triggered long-term complications for his health.

The benign tumor developed on Singh's pituitary gland, a tiny gland at the base of the brain that produces growth hormone. The tumor caused excessive secretion of the hormone, leading to a condition known as acromegaly, which causes gigantism if the tumor is active before puberty and can be fatal if left untreated, said Dr. Joshua Cohen, an endocrinologist at George Washington University.

Despite the surgery on Wednesday, Singh, 39, is at greater risk of facing health problems such as diabetes, hypertension, heart disease and even poor vision if the tumor came into contact with the nearby optic nerves, Cohen said. In 1993, star wrestler Andre the Giant, who stood at 7 feet and 5 inches, and weighed 500 pounds, died at age 46 of congestive heart failure caused by acromegaly.

Susan Manko, a spokeswoman for University of Pittsburgh Medical Center, where Singh was operated on, said Singh was "recovering well in the hospital" and is expected to be released by Monday. Singh has declined to speak to reporters until then, Manko said.

The signs of Singh's acromegaly are instantly obvious, said Dr. Glenn Braunstein, an endocrionologist and chair of the medicine department at Cedars-Sinai Medical Center in Los Angeles — raising the questions, he added, of whether and for how long WWE knew about it, and whether treatment was put off because Singh's surging growth hormone levels were helping him become one of the most formidable wrestlers in the nation.

"The prominent eyebrows, the bulbous nose, the chin protruding, the massive ears — this is quite typical of patients with acromegaly," said Braunstein, who said he could make a clear diagnosis based on the few seconds it took him to conduct a Google image search.

WWE identified Singh's acromegaly at some time prior to his surgery through its Wellness Program, a WWE official said on condition of anonymity because he was not authorized to speak to the press about Singh.

Singh and Andre the Giant — whose real name was Andre Roussimoff and who may be best remembered for his acting role as the giant Fezzik in "The Princess Bride" — are far from the only high-profile wrestlers to have reaped benefits from acromegaly.

Italian boxing and wrestling champion Primo Carrera died in 1967 at age 59 of diabetes, determined years later to be a complication of acromegaly.

Antonio Silva, a Brazilian mixed martial artist and Ultimate Fighting Championship fighter, was suspended from fighting for a year because he tested positive for steroids that his coach said were needed to boost his testosterone levels, abnormally low as a result of his acromegaly.

Six-time world champion wrestler Paul Wight, who goes by the ring name Big Show in WWE, stopped the progress of his acromegaly with a successful surgery on his pituitary gland in the early 1990s.

In a statement, WWE spokesman Adam Hopkins said that "[a]s part of WWE's ongoing wellness evaluation, we are happy that The Great Khali (Dalip Singh) had successful pituitary surgery, and we look forward to him returning to the ring in the near future."

Cohen said Singh could be healthy enough to return to the ring within months, but if he does, it might be at the risk of internal bleeding at the surgical site caused by physical contact.

Dr. Joseph Maroon, who serves as WWE's medical director and led the UPMC surgical team that operated on Singh Wednesday, deferred comment to Hopkins. Dr. David Black, the Wellness Program's administrator, and Dr. Vijay Bahl, a UPMC endocrionologist who serves on the program's group of physicians, could not be reached for comment.

WWE's knowledge of Singh and other wrestlers' acromegaly could put it in a precarious legal position, said Gabriel Feldman, who directs the sports law program at Tulane Law School.

Whether WWE could be held liable for failing to address such conditions depends on the terms of its talent contracts, Feldman said, adding that WWE attorneys are known for the scrupulousness with which they guard the publicly traded but privately controlled company from liability. WWE contracts tend to tilt most of the leverage toward the company, he said.

"This may be more of a moral problem than a legal problem," Feldman said.

Still, he said, the litigation currently facing the National Football League — over players' accusations that the league deliberately withheld information about the long-term effects of concussions — may offer arguments in favor of holding WWE liable for the health problems of acromegalic wrestlers. If the NFL litigation succeeds, he said, it will likely "open the floodgate" to similar lawsuits by athletes in other sports.

WWE established its Wellness Program in 2006, after star wrestler Eddie Guerrero suddenly died of acute heart failure, a result of arteriosclerotic cardiovascular disease. Under the program, Aegis Sciences Corporation annually tests performers for drug use, including steroids, and cardiac problems. In August 2007, Montel Porter, whose real name is Hassan Assad, was diagnosed with a potentially fatal heart disorder in a routine checkup.

Dr. Bryan Donohue, a UPMC cardoiologist and WWE's cardiovascular consultant since 2008, said in his experience, WWE has never put commercial interests above the health of its performers, adding that many WWE executives are former wrestlers.

"The narrative is obvious, that the interests of WWE are antithetical to those of the talent, but I've found that they've been very responsive to things I've asked them to do," Donohue said. "I've never experienced any pushback on any issue."

While Donohue said he could not comment on Singh's case, he said the decision to operate on a pituitary tumor does not follow reflexively from a diagnosis of acromegaly. The timing, especially for adults, can be influenced by a range of factors.

Braunstein, the Cedars-Sinai endocrinologist, said he has seen several acromegalic patients who have refused surgery and even a growth hormone-reducing medication in hopes of preserving their gigantism. When he tells them that acromegaly shortens life expectancy, they often "shop around for other doctors," he said.