“Relapse in Tito illness. Barca coach hit with return of the cancer he had in 2011,” said the Catalan daily Mundo Deportivo, with the same claim carried on the Internet site of the Sport publication.
The Liga leaders said only in a statement that a scheduled news conference for Wednesday lunchtime with Barca president Sandro Rossell had been cancelled, as had a planned Christmas meal with the media.
Vilanova, 44, has been Barca manager since the departure of Pep Guardiola earlier this year. He underwent an operation to remove a tumour on his parotid gland — the largest of the salivary glands — on November 22, 2011.
Reports of Vilanova’s relapse emerged on the same day that a Catalan radio station and Mundo Deportivo said doctors had given the all-clear for Barcelona defender Eric Abidal to play again after undergoing a liver transplant on April 10.
The operation was conducted more than a year after a tumour was removed from his liver.
Vilanova has led Barcelona to the most successful start to a season in La Liga’s history, with 15 wins and one draw in 16 matches so far.
They rule supreme over Spain’s clubs, nine points ahead of runners-up Atletico Madrid and 13 ahead of arch-rivals Real Madrid.
Vilanova played only briefly as a professional in Spain’s top flight, notably with Celta Vigo, before turning to coaching at the end of his career and finding his way back to the club of his youth.
He came through Barcelona’s youth ranks but after failing to break into the first team he continued his playing career with a number of lower league clubs before retiring in 2002.
He rejoined the Catalans as a youth coach in 2007, helping Barcelona’s B side to promotion.
Vilanova was promoted to first team duties, working alongside Guardiola, for the 2008-2009 season, by the end of which the team had won six major trophies including the Champions League.