Paranasal sinus exostoses: possible correlation with cold temperature nasal irrigation after endoscopic sinus surgery.

Exostoses of the external auditory canal (EEAC) are a commonly encountered clinical exam finding; however, exostoses in other locations are vanishingly rare. The postoperative paranasal sinuses are penetrated with cold water solutions, the reputed etiological agent for EEAC, and development of exostoses in this unexpected location may be observed endoscopically. The surprising appearance of these protuberant lesions within the sinuses could be mistaken for more ominous processes, subjecting the patient to biopsy, surgery, or unnecessary medical therapy. The radiologic appearance of exostoses within the paranasal sinuses is herein reported for the first time, and care is taken to distinguish these bony lesions from the osteoneogenesis of chronic inflammation.