Swerdlow and others said the case suggests that the man's attraction to children may have always been present — the tumor simply took away the man's ability to control it.
Strong impulse control may help explain why some pedophiles never break the law.
Most clinicians have given up on changing the sexual orientation of pedophiles in favor of teaching the how to resist their unacceptable desires.
Experts believe that pedophiles who also have a significant attraction to adults stand the best chance of staying out of trouble, because of their capacity for some sexual fulfillment that is legal. For others, injections of hormones to reduce sex drive are often recommended.
Most pedophiles, however, don't receive any attention until they've been arrested.
In an attempt to change that, sex researchers in Germany launched an unusual media campaign in 2005.
"You are not guilty because of your sexual desire, but you are responsible for your sexual behavior," said billboards urging them to contact the Institute of Sexology and Sexual Medicine in Berlin. "There is help! Don't become an offender!"
More than 1,700 men have responded to the print, television and online ads for Project Dunkelfeld — literally "dark field." As of August, 80 had completed a one-year program aimed at teaching them to control their impulses. Some received hormone shots. Compared to men still on the waiting list, those who received treatment were deemed less likely to molest children, according to an analysis of risk factors.
The German researchers promise patients confidentiality. About half of those assessed admitted to having already molested a child.
Though extolled by many researchers, the same program could not be conducted in the United States or many other countries, where clinicians and others are required by law to notify authorities if they suspect a child has been or could be harmed.
There have been some grass-roots efforts to bring pedophilia out of the shadows. Anton Schweighofer, a psychologist in British Columbia, said he recently referred one of his patients to Virtuous Pedophiles, an online support group for men who have never acted on their desires and want to keep it that way.
"I just don't want to get myself in trouble," said the man, a factory worker who spoke on the condition that he not be identified. "I really don't want to harm anybody."
For many pedophiles, a fundamental part of life will always be a shameful secret.
In his late teens, Christiano taught gymnastics and supervised hundreds of young girls. He fasted at work to distract himself from his erotic feelings.
"My hand never slipped," he said. "There were students I loved and adored. In a perfect world, I could sweep them off their feet and live happily ever after."
In this world, however, he has tried to commit suicide three times, he said.
In 1999, he stepped into a federal sting operation when he ordered pornography. He avoided prison but was permanently added to the Illinois sex offender registry.
Once lauded in the Chicago press for his promise as a dance choreographer, Christiano now lives off unemployment, help from his parents and low-paying jobs. He has lost apartments and jobs because of his felony.
"PEDO PIECE OF GARBAGE," read one of many emails he received after an activist group posted a notice about his case online.
His mother, Jennifer Christiano, said that as far back as she could remember, he had always been different from other boys — an odd and creative soul who loved to perform and seemed to worship his female classmates.
"I can't tell you how hard it is," she said. "He's my only child. He'll never truly be happy. He'll never have someone he can truly love and who can love him back."