Floor-reaching middle turbinate variants: Dual pathophysiology and descriptive terminology

The Bolger classification defines three concha bullosa types but does not account for extreme middle turbinate variants extending to the nasal floor. Only one prior report provided quantitative measurements (45mm). We present four patients (32-52mm vertical height) and distinguish primary pneumatization from secondary disease-filled expansion as the underlying mechanisms.

We retrospectively reviewed patients undergoing endoscopic surgery from January 2021 to December 2024 at a tertiary rhinology center. Four patients with middle turbinate extension to within ≤3mm of the nasal floor underwent systematic evaluation including high-resolution CT with standardized measurements (vertical height, width, floor distance), endoscopic examination, histopathological analysis, and surgical management with one-year follow-up.

Four patients demonstrated massive middle turbinate extension with floor contact (32-52mm vertical height); three patients (48-52mm) exceeded the only previously quantified measurement (45mm) by 3-7mm (6.7-15.6%), while Patient 4 (32mm) qualified by floor distance criterion (≤3mm). Patients 1 and 4 represented extreme pneumatization (air-filled concha bullosa, 48mm and 32mm) without sinusitis. Patients 2 and 3 demonstrated secondary pathological expansion (allergic fungal rhinosinusitis 50mm, mucocele 52mm) with sinus involvement. Both mechanisms converged on a similar anatomical endpoint. All patients underwent endoscopic decompression using a systematic anterior-to-posterior technique, with disease-specific adjuncts (sinus clearance, mucocele drainage, frontal sinusotomy) added for Patients 2 and 3, achieving excellent outcomes in all four.

Floor-Reaching Middle Turbinate Variants represent a clinically significant pattern requiring recognition in radiological reporting and surgical planning. Because both mechanisms carry similar surgical implications, descriptive rather than classificatory terminology is warranted. Multicenter validation with standardized measurements is needed before formal classification.