Unilateral opacification of the paranasal sinuses in CT or MRI often indicates an uncommen histological result.

Background: Clinical and radiological differentiation between subacute or c hronic sinusitis and differential pathologies such as malignoma, inverted p apilloma or mycosis can be very difficult. In some cases the CT- or MRI-sca n shows a unilateral opacification of the paranasal sinuses. Which histolog ical results can be found in patients with persisting sinusitis related pro blems and a unilateral opacification of the paranasal sinuses in the CT-or MRI-scan? There are only a few publications on this topic. Patients: in a p rospective study between June 1998 and November 1999 all patients who under went surgery in our Department for subacute or chronic sinusitis problems w ere included into our study group if they had a unilateral opacification of the paranasal sinuses. Thereafter, the same neuroradiologist verified the unilateral radiological findings on CT or MRI, unaware of the clinical and histological findings. Cases with a pre-existing histological examination, previous operation or injury to the paranasal system were excluded from thi s study. Data on clinical symptoms, radiological and histological findings were analysed. Results: 43 cases with unilateral opacified paranasal sinuse s were diagnosed by means of CT or MRI. These were comprised of 24 males an d 19 females with an average age of 43.6 years (range 6 to 88 years). The m ajor findings of our study were as follows: Firstly unilateral opacificatio n of the paranasal sinuses is often (19/43 cases or 43 %) associated with d iseases other than simple chronic sinusitis (8 inverted papilloma, 5 malign oma, 3 mycoses and one brown tumor, one osteoidosteoma and one haemangioma) . Secondly the incidence of significant pathology other than simple chronic sinusitis rises strikingly with increasing age of the patient. For instanc e pathologies other than simple chronic sinusitis were found in 14% (1/7) o f cases in the under 16 years group, 27% (6/22) of cases in the 16-60 years group and in 86% (10/12) of cases in the over 60 years group. Concerning c linical signs of our patients with unilateral sinus opacity 7 of 11 patient s (63 %) with epistaxis and 3/5 with diplopia had histological findings oth er than simple chronic sinusitis. In contrast unilateral rhinorrhea, unilat eral nasal congestion and cephalgia were not of predictive value. Conclusio n: Unilateral opacification of paranasal sinuses in the CT or MRI is - espe cially at a higher age - an indice for a neoplasm or mycotic sinusitis and therefore an early histological diagnosis or operative treatment is always suggested.