Cystic Fibrosis (CF) predisposes patients to nasal and paranasal diseases such as chronic rhinosinusitis, nasal polyposis and mucocele. The involvement of the upper airway in patients with CF is well known, indeed many patients develop chronic rhinosinusitis (CRS) that negatively affects the quality of life and the lung disease progression. Patients with the classical phenotypic expression of CF show a high incidence of CRS, which is around 100 %. These patients also have a high incidence of nasal polyposis (7–48 %). Another very common complication in patients with CF is mucocele, which has a high prevalence in both adult and pediatric age. Mucocele can progressively increase in volume due to the accumulation of secretions, dislocating and destroying the surrounding bone tissue (mass effect) with local, orbital and intracranial complications [1], [2], [3].

In recent years, attention has been focused on the rhinosinus disease in CF as numerous studies have shown that sinus involvement can exacerbate lung injury. Sinuses are colonized by bacteria before the lungs, so they become a reservoir of early colonization of the airways, where bacteria diversify, develop antibiotic resistance and adapt to the airways; from the paranasal sinuses the bacteria intermittently migrate and colonize the lungs and can ultimately induce a chronic pulmonary infection. The loss of upper airway functions in filtering, humidifying, heating the inhaled air can in itself aggravate the lung damage due to the increased frequency of respiratory infections. Patients with CF may also present facial deformations such as hypertelorism, proptosis and enlargement of the root of the nose due to the progressive expansion of the polypoid formations [4], [5], [6], [7].

In addition to the clinical examination and the rhinofibroscopy, imaging techniques, especially the CT of the paranasal sinuses, are used to highlight any alterations in the nasal and paranasal cavities. Some features of CF associated sinonasal disease can be easily detected by CT, such as the hypoplasia of the frontal and sphenoid bone, the bone demineralization, the displacement of the uncinate process, the swelling of the lateral wall of the nose and the sclerosis of the bone. Often the maxillary sinus is small (medial wall usually exteriorized in the nasal cavity), the anterior ethmoid sinus grows faster than the posterior one, causing an inversion of their relationship throughout the ethmoid labyrinth. The presence of frontal agenesis and the opacification of the maxillary and ethmoid sinus by >75 % have been proposed as pathognomonic criteria for CF. In addition, CT is the gold standard for the planning of sinonasal surgery and is also essential for the re-evaluation after surgery [8], [9], [10].

Conservative medical therapy, based on nasal washes, topical steroids, antibiotics is the first step for treatment.

On the other side, patients with CF and persistent symptoms, in which medical treatment has been unsuccessful, are considered excellent candidates for surgical treatment.

The most used surgical treatment is FESS (functional endoscopic sinus surgery) which has the main advantage of being less invasive than other interventions. More recently, another technique that is employed in the extensive treatment of rhinosinus disease is CESS (centripetal endoscopic sinus surgery). The rational for the more invasive technique is based on the fact that the paranasal sinuses represent a reservoir of bacterial colonization. In particular, while the facial, maxillary and sphenoidalsinuses are unique, the ethmoid sinus consists of cells that allow the nesting of the bacterial colonies inside them [11], [12], [13].

Given the high prevalence of rhinosinus disease in CF and considering the uncertainties regarding follow-up, morbidity and management, the objectives of this retrospective study are manyfold:

To analyze the possible differences between clinical, demographic or genetic characteristics, in patients with CRS with different phenotype;

To describe the possible benefit of surgery with CESS.