The story first emerged in Catalan publication El Mundo Deportivo. The club have cancelled all media activities scheduled for Wednesday and have said that they will be making a statement later in the day.
Vilanova, 44, had a tumor removed from his parotid gland in November 2011 when he was assistant coach at the Camp Nou. After Pep Guardiola resigned at the end of last season, Vilanova stepped into his position and has led Barcelona to the best ever start to a La Liga season.
Following a 4-1 victory over second-placed Atletico Madrid on Sunday, Barcelona sit nine points clear at the top of the table and are 13 points in front of last season’s champions and bitter rivals Real Madrid.
The news of Vilanova’s condition comes just a day after Lionel Messi, Xavi and Carlos Puyol agreed to new long-term contracts and also follows news that Eric Abidal was ready to return to the club after a liver transplant.
It is a much more somber atmosphere that engulfs the Blaugrana on Wednesday.
"Barcelona announce that it is has suspended the press conference from president Sandro Rosell planned for midday,” read a club statement. “As well as that, the media Christmas lunch has been cancelled.
"Later today the club will issue a further release. Until that time we will not make any announcement about this matter. We regret any inconvenience this decision may cause."
While wishes of support poured in for Vilanova from across the soccer world on Twitter, thoughts have also turned to who might step into the breach should the Barcelona boss have to step down either temporarily or permanently.
The first name on everyone’s lips has been Guardiola. The man who led the Catalan giants to unparalleled success during his four years in charge is currently enjoying a sabbatical in New York and has previously said that he would not join another club until at least next summer.
Although, given his emotional connection to Barcelona and close friendship with Vilanova, if there is a situation that could tempt him to make a hasty return then this may be it. However, El Mundo Deportivo claim that the club has denied making contact with Guardiola.
The report also suggests the same scenario regarding contact with former Barcelona player and one-time B team coach Luis Enrique. The former Spain international left the Camp Nou to take up the manager’s position at Italian side Roma in 2011, however he left after just a season in charge.
With Vilanova said to undergo surgery on Thursday, perhaps the most likely scenario is for current assistant coach Jordi Roura to be handed the reins.
The 45-year-old was appointed from the position of opposition scout to become Vilanova’s right-hand man this summer.