PHILADELPHIA -- A madam-turned-faux cosmetic surgeon kept up the ruse of being a medical expert even as a 20-year-old dancer who received illegal buttocks injections began to die, prosecutors told jurors Friday as her murder trial went to a jury.

The strippers, transgender women and "regular girls" who sought injections from defendant Padge-Victoria Windslowe at "pumping parties" and airport hotels were young and vulnerable, a prosecutor said.

The dancer, Claudia Aderotimi of London, died after Windslowe struck a vein and sent silicone to her lungs, doctors said.

"They're literally dying to be beautiful," Assistant District Attorney Bridget Kirn said in closing arguments.

Some clients had a half-gallon (two litres) of industrial-grade silicone injected into their buttocks at one time and often came back for more. But it sometimes paid off -- one exotic dancer said she could earn $1,000 an hour working in a gentlemen's club. The injections typically cost $1,000 to $2,500 per session.

The three-week trial has lifted a veil on the underground demand for silicone buttocks enhancement. At least four women have died around the country, including a Las Vegas mother of three whose body was left on a street after she died from injections done inside a tile store. A Columbian couple pleaded guilty to manslaughter in that case.

Windslowe told jurors that she learned the lucrative business from doctors in Thailand and Ecuador who performed her sex-change surgeries.

She said she has since performed thousands of the procedures on devoted clients, earning the name "the Michelangelo of buttocks injections."

Defence lawyer David Rudenstein urged jurors not to judge his client's "lifestyle," which included her turns as "the Black Madam" at the escort service, as a dominatrix in slickly produced music videos and as "Lillian" in her buttocks-injection business.

However, Kirn said she changed her name and address every time someone was injured. The $1,000-an-hour dancer spent two days in the hospital after silicone particles went to her lungs. She said she has severe heart problems now that limit her ability to play with her young son.

Windslowe, 45, conceded that she bought cheap silicone, mixed it with saline in her home blender, and put it in red plastic cups and water bottles when she went to work.

Aderotimi had come to Philadelphia for the weekend with friends to celebrate her birthday with a $1,800 follow-up visit to Windslowe.

"My client's not a murderer," Rudenstein argued. "It's clear she gave butt injections. ... The people who saw my client came from a certain walk (of life). They weren't going to a medical office. They were going to a hotel room. They were all kind of in it (together)."

The charges include third-degree murder, manslaughter, aggravated assault and practicing medicine without a license.