The goal of this observational study is to learn about anatomical and pathological variants in patients with antrochoanal polyps trying to find a key to its pathogenesis Participants will have nasal endoscopic examination and CT nose and paranasal sinuses.

we will compare patients with antrochoanal polyps and other patients with unilateral sinonasal disease regarding anatomical and pathological variants.

This study was conducted at Otolaryngology department, Minia University Hospital, Minia, Egypt. The study was approved by the Institutional Review Board at Minia University.

The study participants were recruited from patients complaining from unilateral sinonasal disease attending outpatient clinic.

we selected 40 patients with ACPs who had the following inclusion criteria: 1-radiologically diagnosed based on CT nose and PNS. 2-histopathologically diagnosed as ACP. The radiological diagnosis is based on seeing low attenuated soft tissue mass filling the maxillary antrum and extending through the middle meatus into the nasal cavity and directs towards the post nasal opening. We excluded: 1- patients with history of maxillofacial trauma. 2- patients who had previous nasal surgery.

To be more objective, a control group of 40 patients who had unilateral sinonasal disease other than ACP was formed.

We assessed multislice computed tomography (CT) nose and paranasal sinus images by Toshiba aquilion CT scanner. Axial and coronal 250mm cuts were obtained.

Both study and control groups were compared regarding anatomical and pathological variations in the nose. These variants include: deviated nasal septum, concha bullosa, paradoxical middle turbinate and uncinate process insertion (to lamina papyrecea or roof of ethmoid or middle turbinate). We also compare between them according to presence of retention cyst in CT in contralateral side In the cases with deviated nasal septum, the septal deviation was seen if it is towards the side of the lesion or towards the opposite side according to its convexity.

We also evaluate the sclerosis on thickening of the bony wall of the para nasal sinus as an indication of chronic inflammation.

SPSS 24.0 program was used for statistical analysis. Averages and standard deviations were calculated. The Mann-Whitney and Chi square tests were used for comparisons between the groups. The Pearson correlation tests was used to evaluate correlations. Statistical significance was set at ≤ 0.05.

Inclusion Criteria:

1. radiologically diagnosed based on CT nose and PNS.
2. histopathologically diagnosed as ACP.

Exclusion Criteria:

1. patients with history of maxillofacial trauma.
2. patients who had previous nasal surgery.

The study participants were recruited from patients complaining from unilateral sinonasal disease attending our outpatient clinic.