De Laurentiis told Radio Monte: "Cavani is a warrior who embodies all that's best of the Napoli spirit and our supporters. It is because of this I turned down an offer of €55m."
"Cavani has become the symbol of our resurgence. If I have kept him here it is not because of money, but a love for the club," added the team chief of the 25-year-old striker, who has scored 13 league goals this season.
Cavani arrived at Napoli having spent three seasons with Palermo.
Napoli are fifth in Serie A, ten points behind leaders Juventus.