Mandy Sellars is your typical, single 34-year-old woman. She loves to go the movies, hang out with her friends, go out for lunch and have a good chat. But there is just one thing that sets Sellars apart: She suffers from a rare condition that has caused her legs to grow at an alarming rate.

“When I was born, they knew straight away that there was something completely different about me,” Sellars, who lives outside of Manchester, England,told FOXNews.com.

“They actually didn’t let my parents see me. They took me away from my mom and I think they kept me away from my parents, particularly my mom, for about 10 days or 14 days.”

PHOTOS: Mandy Through the Years

Doctors were concerned because Sellars was born with abnormally large legs and feet. At the time, they didn’t have a diagnosis, and it wasn’t until she was about 2 years old that her parents were told she had lymphedema, which causes extreme swelling in your arms and legs. The problem was – it was the wrong diagnosis.

“Well, I’ve never had lymphedema – it isn’t that condition at all,” Sellars said.

Still, more than 30 years later, doctors have still not officially diagnosed Sellars with a specific condition, although some believe she has a rare disorder called Proteus Syndrome – a condition also thought to have affected Joseph Merrick, the “Elephant Man.”

Proteus Syndrome is “characterized by the progressive abnormal growth of body tissues,” the National Institutes of Health says on its Web site. Its cause of is unknown.

Click here for more information on Proteus Syndrome.

“So at the moment it’s still really a guessing game as to exactly what this is – but Proteus Syndrome is a label I can put on it,” she said.

Although Sellars faced great challenges as a child, she didn't let her disorder slow her down.

“I wasn’t really held back in anything,” she said. “I could run around and play soccer and play outside with my friends at home – even climb trees and things like that. So to me, it was just like an average childhood, really.”

Sellars excelled in school and went to college to study graphic design – eventually taking courses in sociology, psychology and criminology. Her dream job is to become a forensic scientist, but so far her condition has prevented her from fulfilling that dream. Over the years, the disorder has resulted in her legs consistently growing larger and larger, which has greatly affected her mobility. When Sellars was in her late 20s, she suffered a major setback and wound up in the hospital paralyzed from the waist down for about 10 weeks.

“It could’ve been DVT (Deep Vein Thrombosis), or it could’ve been some virus that caused this,” she said. “That was the first time that anything particularly major had happened to my health. I haven’t been 100 percent since then.”

As a result, she now uses crutches to walk around.

“Luckily I have very strong muscles, which help me walk around and get dressed and do the daily things that need to be done,” Sellars said. “But I mean, just walking is exercise for me… you know, because I’m getting a workout just doing that.”

The Future

Sellars weighs 280 pounds, and she says her legs tip the scales at more than 100 pounds each. Still, She drives a specially equipped car and lives on her own.

As for the future – Sellars faces some tough decisions. Because her legs continue to grow ever larger, the only option she has been offered is amputation.

“I have been to see a doctor in London about the amputation, but it’s still up in the air at the moment as to what exactly would happen,” she said. “The doctors suggested a hip disarticulation, where they cut your leg off at the hip joint, but to me that’s just unreasonable.”

Sellars said she is waiting to see a doctor in Liverpool to look at some other options. But in the meantime, she’s focused on just one simple mission.

“My goal is to keep on walking as long as I can,” she said. “That’s the goal from today, tomorrow, the next day, next week and next month. Obviously, having my legs amputated is quite scary... but I look at it in a way that once I have my legs amputated, it will be a new kind if life – it won’t be any better or any worse from the life I have now – it will just be a different life and a start of a new chapter.”