CT scan 3 months after local and systemic corticosteroid therapy. (a) Coronal section : subnormal left frontal (*) and maxillary sinuses (x). Right middle meatus obstruction (arrow); (b) Axial section : right ethmoidal cells (+) and sphenoid (#) are free; (c) Axial section : opacity of the right maxillary sinus; (d) Sagittal section : Stage 1 polyp in the left maxillary sinus (p). Insufficient improvement with disabling hyposmia: indication for bilateral polypectomy, middle meatotomy and anterior ethmoidectomy.