One-way cruise to or from Brazil

Hoping to find a cruise ship we can take either from Brazil (preferably Fortaleza, where we live but would consider other ports) to the U.S., or one-way U.S. to Brazil. Did see a Princess Cruise going from Ft. Lauderdale to Fortaleza, then on to Senegal and Italy, but Princess folks said the price would be the same for Ft. Lauderdale-Fortaleza (about 5 or 6 days) as for the entire 20-day cruise to Italy. Any ideas? Thanks!