A Niigata Prefecture hospital recently found a piece of gauze left inside a patient's abdomen from surgery it performed on him 27 years ago, officials said Tuesday.

The gauze, with one side about 2 cm wide, was found in a tumor removed in January from a man in his 60s who lives in the city of Joetsu, officials of the Chuo Hospital said.

In December, the patient complained of abdominal discomfort and went to a different hospital, where he was diagnosed as having a tumor, according to Atsushi Abe, chief of Chuo Hospital. The following month, he underwent surgery at Chuo Hospital to have the tumor removed.

The gauze was found when the hospital tried to extract a tumor biopsy. After checking the patient's medical records, the hospital found that the gauze was left inside the man when he underwent an operation at the same institution in 1977 to have an organ removed, according to Abe.

It is possible the patient developed the tumor because of the gauze, he added.