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 conditions. 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 except osteoma cases were reviewed retrospectively between 1994 and 2016. We compared demographic data between the surgery and observation groups. Reason for image study, radiographic features, histopathology, and clinical course with serial image scans were analyzed. Results A total of 183 subjects were selected from a thorough review of head and neck radiologic tests (n= 606,068) in a tertiary referral hospital over 22 years. The mean age was 28.6 ± 18.1 years, and 56.3% were males. Diagnostic image workup was performed in 55.7% of patients due to facial asymmetry, headache, skull mass, or other symptoms related to BFOLs. Other patients (37.7%) found BFOLs incidentally on a CT or MRI. The most common diagnosis was fibrous dysplasia, followed by ossifying fibroma, in both radiology exams and histopathologic results. In total, 42.6% of patients underwent surgery because of subjective symptoms or esthetic concerns. The surgery group was younger (p < 0.001) and had a longer follow-up duration (p < 0.001) compared to the observation group. Patients who experienced increased lesion size (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 are 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.