People (medical professionals included) perceive environmental details in different ways, which sometimes results in different interpretation of disease symptoms and results of accessory investigations. This leads to establishing diverse diagnoses in the same patient, which may also occur in children with chronic sinusitis. The disease is due to persistent upper airway obstruction, obstruction of the natural ostia of the paranasal sinuses, and it is also present in acquired or congenital immune deficits (1, 2).

Computed tomography (CT) has become an unusually valuable tool in the diagnosis and treatment of children with chronic sinusitis. The examination helps offer an effective treatment to children who, so far, have only been condemned to complaints associated with chronic sinusitis. The treatment, however, depends on the perceptive assessment of scans obtained on CT examination. With remarkable frequency, CT reports focus mainly on opacities in particular sinuses. However, only 30% of children with chronic sinusitis treated surgically at the Department of Paediatric Otorhino-laryngology, were found to have intraoperative abnormalities compatible with those reported by radiologists. In the remaining 70%, intraoperative eva-luation showed normal sinuses or sometimes mildly hyperaemic sinus mucosa.

Relatively often, doctors describing false-positive or false-negative CT scans in their reports, estimate the patency of the ostiomeatal complex. In the case of preserved patency of the ostiomeatal complex, its obstruction or the ostiomeatal complex itself, is sometimes recognized as normal when, in fact, it is narrowed by, e.g., Haller´s cells. The concha bullosa is a structure affecting the nasal patency, however, it is very frequently missed. In hypoplasia of the maxillary sinus, the sinuses are described as opacified, and densitometry of the tissue filling the sinus is not performed. Densitometry may help distinguish the osseous tissue filling the underdeveloped sinus from soft tissues; therefore it is vital to estimate size disproportions of both sinuses in such cases (Fig. 1).

An unusually disturbing CT finding may show the evidence of osseous destruction, and therefore we would like to present the case of a 13-year old boy admitted to the Department of Paediatric Otorhinolaryngology, with the diagnosis of adenoid hypertrophy. Laryngo-logical examination revealed a polyp in the right nasal cavity. Sinus CT showed a mass destroying the lateral nasal wall and parts of the nasal septum (Fig. 2).

In the perioperative period, auscultation revealed abnormal pulmonary signs for which the child was admitted to the pneumonological ward, where primary ciliary dyskinesia was recognized. Subsequently, functional endoscopic sinus surgery was performed at our Department. No destruction of the lateral nasal wall and nasal septum was found at operation. Histo-pathological examination of the removed tissue showed evidence of nasal polyps.

1. The presence of oedematous lesions without other findings on single computed tomography scan of the sinus is not an indication to surgical treatment.

2. Destruction of the osseous structures visualized in CT scans requires urgent histopathological evaluation.

3. In doubtful cases, radiological and laryngological consultations are of high significance.

4. Prior to surgical operation, surgeons should do the assessment of the sinus CT scans by themselves.