A 38-year-old man from Delhi presents with a 3-year history of progressive nasal obstruction, rhinorrhea, and recurrent sinusitis. On nasal endoscopy, multiple bilateral smooth, pale, gelatinous masses are seen arising from the lateral nasal wall and maxillary sinus ostium. CT paranasal sinuses shows opacification of bilateral maxillary and ethmoid sinuses with multiple polypoid masses. He reports no history of asthma or aspirin sensitivity. Which is the most likely diagnosis?