The Primera Division club's medical department revealed in a statement that the 44-year-old would have surgery on his parotid gland on Thursday, before undergoing approximately six weeks of chemotherapy.
The news comes just over a year after Vilanova first had a tumour removed from his throat. "Tito is strong, very strong. He's shown us that and we're convinced he'll be back with us very soon," club president Sandro Rosell told a press conference.
Rosell also expressed his "unconditional support" for Vilanova at a press conference, in which he was flanked by on-field leaders Carles Puyol, Xavi, Andres Iniesta and Victor Valdes.
Rosell revealed assistant coach Jordi Roura would take charge of the first team while Vilanova, who took over from Pep Guardiola at the Nou Camp this summer, underwent his treatment.
The club has, however, left the door open for Vilanova to return to the touchline during his recovery, saying in a statement that his "treatment may be compatible with his work life". That decision is set to be made after Thursday's surgery but for now Rosell offered the club's full support for Vilanova and his young family.
Rosell added: "We want to express our unconditional support to Tito and his family. We thank everyone for their support. We have complete confidence in the team. The club is very strong and united, we're capable of overcoming adversity."