A 26-year-old man is taking legal proceedings against St Vincent's University Hospital in Dublin after a mix-up which has left him with no stomach.
Lawyers for Alan O'Gorman claim his tissue samples were mixed up with those of a 70-year-old man with stomach cancer.
Mr O'Gorman, from Ratoath, Co Meath, is suing the hospital and senior doctors who treated him.
He went to hospital in February 2002 with severe stomach cramps. After an operation, he was told he had a perforated ulcer.
But his lawyers say tissue samples taken during the operation were mixed up with those of a much older man who had stomach cancer.
Surgeons believed Mr O'Gorman had stomach cancer and removed his stomach just over a month later.
Before the operation, Mr O'Gorman asked surgeon Justin Geoghegan if there was any chance there could have been a mistake in his diagnosis.
Mr O'Gorman's lawyers claim the surgeon replied: 'We don't make mistakes like that here.'
The court was told Mr O'Gorman can now only eat small amounts of food very slowly. He gets tired very easily and may only be able to work part-time in the future.
The defendants deny all the claims.
The case is expected to last two weeks.
