Long-Term Clinical Course of Benign Fibro-Osseous Lesions in the Paranasal Sinuses

Objectives. Fibro-osseous lesions of the paranasal sinuses can present various clinical manifestations. This study aimed to report the long-term clinical course of benign fibro-osseous lesions (BFOLs) in the paranasal sinuses, including clinical and radiologic features. Methods. Radiologically confirmed BFOLs between 1994 and 2016, with the exclusion of osteoma cases, were retrospectively reviewed.We compared demographic characteristics between the surgery and observation groups. The reasons for the imaging study, radiographic features, histopathology, and clinical course based on serial image scans were analyzed. Results. In total, 183 subjects were selected from a thorough review of head and neck radiologic tests (n=606,068) at a tertiary referral hospital over 22 years. Patients’ mean age was 28.6±18.1 years, and 56.3% were males. A diagnostic imaging workup was performed in 55.7% of patients due to facial asymmetry, headache, skull mass, or other symptoms related to BFOLs. In other patients (37.7%), BFOLs were found incidentally on computed tomography or magnetic resonance imaging. The most common diagnosis was fibrous dysplasia, followed by ossifying fibroma, based on both radiologic exams and histopathologic results. In total, 42.6% of the patients underwent surgery because of subjective symptoms or esthetic concerns. The patients who underwent surgery were younger (P<0.001) and had a longer follow-up duration (P<0.001) than those who underwent observation. Patients who experienced lesion growth (11.5%) were younger (P<0.001) and had more lesion sites (P=0.018) than those who did not, regardless of surgical treatment. Five patients underwent optic nerve decompression, and one patient experienced malignant transformation. Conclusion. BFOL in the paranasal sinuses is a rare disease, and most cases were observed without specific treatment. Surgical treatment should be considered in symptomatic patients with aggressive clinical features. Regular observation and management are needed, particularly in younger patients in their teens.