Tumors are an unfortunate part of the human experience for many people. They come in a variety of shape and sizes, but for one man in China, his tumor grew to an exceptionally large size. In fact, it was so big that it weighed 238 lbs was dubbed “The World’s Largest Tumor”.

Thirty-seven-year-old Yang Jianbin from Shanxi Province, China, was born with a birthmark on his leg that slowly grew over time. Yang first noticed that it was getting bigger when he was nine years old, and it continued growing for almost another 30 years.

By the time Yang was 12 years old, the tumor was the size of a fist and that was when he first had surgery to remove it.

Despite this operation, the tumor came back and continued to grow again.

According to Beijing surgeon Chen Minliang, the tumor was caused by Neurofibromatosis. This is a genetic disorder which affects the growth and development of cell tissue. While most people with the condition live normal lives, a small handful like Yang are severely affected.

The video below details how the tumor affected Yang’s life:

“We have seen neurofibromatosis patients before, but this is the biggest nerve tumor we ever saw,” Minliang said.