Martin Castrogiovanni will sit out the rest of the Rugby World Cup after scans found a tumour in his back.
Italy's team doctor Luigi Troiani confirmed the news with the hugely experienced prop flying to Milan for treatment.
"Martin has pain on a sciatic nerve and after a check doctors found a tumour pressing on his fifth vertebrae that is causing inflammation and pain," Troiani said. "We are sure it is benign and tomorrow he will fly to Milan to see a specialist and the likelihood is he will require surgery."
The veteran tight-head later took to his Facebook page to send the Italy fans a message: "I always give my all for Italy. I have never held back but this time is different; I have to stop because I have to think about my health. For the first time I have to put myself in front of the team, in front of my comrades.
"After months of intense preparation and spending the whole summer training for this important goal I'm so sorry to have to abandon the World Cup. Be assured that we'll meet again soon!"
Castrogiovanni is one of three Azzurri players who will miss their final pool stage game against Romania on Sunday, a match Italy need to win if they are to avoid having to qualify for the 2019 World Cup.
Michele Rizzo and Gonzalo Garcia will also sit out the match due to knee injuries. But in more positive news for the Azzurri, they could have vice-captain Leonardo Ghiraldini fit for Romania with Troiani saying the hooker is "confident" of being fit for Sunday.