BEIJING (Reuters, Nov 15) - Chinese doctors operating on a woman with abdominal pain expected to find an inflamed appendix but discovered a football-sized 15-kg (33-lb) tumor instead, a Beijing daily reported on Thursday.

Surgeons at the capital's Chaoyang Dongba hospital spent 30 minutes removing the tumor from Xiao Wen's abdomen, the Beijing Times said. It measured 40 cm (16 in) by 30 cm (12 in) and is believed to have been benign.

"It's just unbelievable, who would have thought a stomach could have such a large tumor?" the 21-year-old's father said.

One surgeon who operated on Xiao Wen said he had not seen such a large abdominal tumor in more than 20 years of medicine.

"If it hadn't been taken out in time, it could have spontaneously burst, threatening her health," the paper quoted him as saying.

Her family had not noticed anything wrong with Xiao Wen's stomach as, at 114 kg (251 lb), she was already "comparatively fat", the paper said.

Xiao Wen, whose weight ballooned after she developed a lymphatic disorder as a child, said before the operation that she hoped it "could help her lose weight"

(Reporting by Ian Ransom; editing by Roger Crabb)