The work, called Icon, won a medal of excellence and it so impressed the City Guilds examination board that they included it in a promotional video. Then they lost it.
Caroline Park, design and embroidery tutor at Malvern Hills College, was told that the exhibits of Hilary and those of other students had been accidentally cleared out and dumped on a landfill site.
"I was so shocked," she said. "Her piece was beautiful. She had even made the frame.
"They said a lot of work had been lost. Quilts and other large pieces of work had gone missing, pieces which obviously weren't rubbish. It was absolutely incredible" Ms Rochford-Dyer took the embroidery and design course after winning her battle against breast cancer, diagnosed eight years ago. The triptych took her 18 months to complete.
"It just seems beyond belief that anybody could take these beautiful articles and toss them in a skip," she said. "By the time the discovery was made it was on its way to a landfill site outside London and had already been buried. We aren't allowed on site to look for these things."
She said City Guilds had sent her flowers and a card apologising for the loss. She rejected an initial offer of compensation, which she described as "derisory", but has since accepted a higher offer.
"It's absolutely appalling really. I had lots of local exhibitions last year and at no time was my work threatened.
"But you leave it with people who know all about art and the creative process and it goes missing. In my view they have been negligent."
In a statement, City Guilds said: "Unfortunately a number of creative studies artefacts were destroyed by contractors in March 1998.
"All those involved were immediately contacted by phone and in writing and told what had happened.
"An independent assessment of value was undertaken. Compensation was offered on an individual basis and was accepted by all those involved in full and final settlement of any claim they might have resulting from the loss."
City Guilds spokesman Michael Osbaldeston declined to say how many students lost their work.
He said: "Everybody to our knowledge was happy to receive the compensation that was offered, and as far as we're concerned the matter is closed."