The lamellar cell: a radiological study and a new classification proposal.

Purpose: A pneumatized middle turbinate is called concha bullosa. Bolger classified it in bulbous, lamellar, and extensive. Lamellar cells could have a variable extension. We propose the first radiologic classification of lamellar cells.
Methods: 195 CT sinonasal scans were included in the study. Lamellar cells were classified into four categories according to their degree of aeration.
Results: Lamellar cells were found in 47.7% of patients: unilateral in 14.9% of cases and bilateral in the remaining 32.8%. The most common lamellar cell is type 1, followed by types 3, 2, and 4; there were no statistically significant differences regarding side. A subgroup analysis was performed in 106 patients with no inflammatory diseases of the nasal cavity; there were no significant differences.
Conclusion: Cell types 3 and 4 are a complete pneumatization of the insertion of the middle turbinate; these cells are rare and could be associated with middle turbinate instability.