Three distinct clinical entities exist that can be classified as fibro-osseous lesions of the paranasal sinuses: osteomas, fibrous dysplasia, and ossifying fibroma. Although their appearance and presentation may be somewhat similar, their clinical implications vary tremendously.

Osteomas are the most common tumor of the paranasal sinuses. These benign, bony tumors are most commonly located in the frontal sinus (80%), with the remainder occurring in the ethmoid (20%), maxillary (5%), and sphenoid (rare). Symptoms from paranasal sinus osteomas commonly result from their ‘mass effect’ on surrounding structures. Common symptoms include frontal pain and headache, as well as sinusitis and/or mucocele formation from resultant obstruction of adjacent sinus ostia. As mentioned previously, osteomas may also present as incidental findings on various radiologic studies performed for non-rhinologic purposes.

The primary dilemma in the management of osteomas, is determining whether or not surgical resection is necessary. Many surgeons advocate observation with periodic CT imaging at 6 month intervals in asymptomatic patients. This, in turn, allows for surgical intervention and decision making prior to the development of complications, should a lesion increase in size on serial imaging. While small, asymptomatic lesions may be observed, larger, symptomatic tumors should undergo surgical resection.  Rapid growth, infection, compression of vital structures, severe pain, facial deformity, vision changes, mucocele formation, and intraorbital and/or intracranial complications are all indications for tumor resection. Those tumors that warrant surgical resection can usually be managed with minimally invasive procedures and approaches involving endoscopic or combined endoscopic/open techniques.