[Atypical cystic fibrosis. First diagnosed by chronic rhinosinusitis].

We present the case of a 44-year-old wrestler suffering from persistent bronchitis and chronic rhinosinusitis which had been refractory to therapy. The patient underwent extensive diagnostic examinations throughout the disease. Recently, at the age of 42 years otorhinological controls led to presentation at a cystic fibrosis (CF) centre where CF with the genotype Fdel508/3849+10 kb C-->T was diagnosed despite borderline sweat tests. Atypical CF should be considered in chronic persistent rhinosinusitis even in patients with borderline sweat tests.