Concha bullosa. A radiological study and a new classification.

OBJECTIVE: A pneumatised middle turbinate is called concha bullosa. It has been classified according to its extension in the coronal plane. We propose the first classification according to the axial extension of pneumatisation of the middle turbinate.

MATERIAL AND METHODS: Bulbous concha bullosa was classified in six categories according to the degree of pneumatisation of the body of the middle turbinate in the axial plane.

RESULTS: 196 CT sinonasal scans were included. 28.06% of patients had concha bullosa, unilateral in 13.26% and bilateral in 14.79%. The most common concha bullosa found was type I, followed by type III, II, IV and V. There were no statistically significant differences by side, between the patients with or without chronic rhinosinusitis without polyps.

CONCLUSION: Our results support the hypothesis that concha bullosa is not related to chronic rhinosinusitis. Furthermore, type IV and V cells mean posterior aeration of the middle turbinate. Those variations are rare and posterior, so they can easily pass unnoticed during endoscopic sinus surgery. Our classification is also important as a surgical reference, and it can be easily studied on the preoperative CT scan.