<p class="abstract"><strong>Background:</strong> Osteomas, ossifying fibromas, and fibrous dysplasia comprise a set of benign neoplasms known as fibro-osseous lesions (FO), which can arise in the paranasal sinuses. The vast majority of benign FO lesions (BFOL) are incidental findings on radiographs. They tend to be slow-growing tumors, and are infrequently symptomatic. The management strategy can vary significantly for theses lesions. This can range from serial, observations to aggressive surgical resection, based on symptomatology, size, and location of the lesion.</p><p class="abstract"><strong>Methods:</strong> Retrospective analysis of all the data of different symptomatic FO of the paranasal sinuses and the skull base was performed at King Fahad specialist hospital, Dammam, KSA (2006 to 2017).  </p><p class="abstract"><strong>Results:</strong> A total of 21 patients were identified; 10 (46.7%) patients were diagnosed with osteoma, 8 (38.1%) with fibrous dysplasia, 2 (9.5%) with ossifying fibroma and one (4.8%) with juvenile active ossifying (JAOF), 17 were adults and 4 were children, the range of f/u (3-60) months. 19 patients were managed by the endonasal endoscopic approach. They continue to be followed with no evidence of recurrence. Two cases required the revision combined endoscopic open approach to ensure adequate removal of the disease (residual and recurrence).</p><p><strong>Conclusions:</strong> Diagnostic dilemma of BFOL can be overcome with a combination of clinical, radiological and pathological criteria. Correct diagnosis of fibro-osseous tumors is crucial for adequate therapy as their treatment, prognosis, clinical aggressiveness and long term complications of individual entities vary significantly. Endoscopic computer-assisted surgery is the treatment of choice. Endoscopic resection remains a technical challenge. </p>

Introduction: Isolated sphenoid inflammatory disease is a rare clinical condition among patients with paranasal sinus disease, reported incidence between 1%-3%. 1 The most common symptoms of isolated sphenoid inflammatory lesions are headache, ophtalmological and nasal symptoms. Delayed diagnosis may occur due to its nonspecific symptoms. 2 The disease requires appropriate and good imaging technique for diagnosis. The aim of the study to discuss different pathologies of isolated sphenoid inflammatory lesions. Patients and methods: From 2008 to 2017, we performed surgery on 27 patients with isolated sphenoid inflammatory disease. The presenting signs and symptoms, radiological studies, operative findings, and clinical outcomes were retrospectively reviewed and analyzed. Results: 27 cases were identified at tertiary hospital of King Fahad Specialist Hospital Dammam. 12 bacterial sphenoid sinusitis, 4 allergic fungal sinusitis, 4 fungal balls, 2 invasive fungal sinusitis, 3 pediatric (2 sphenoid sinusitis and 1 allergic fungal sinusitis), 1 mucocele, 1 mucopyocele. Conclusion: Isolated sphenoid inflammatory disease is rare, with comprehensive history taking, complete physical examination, appropriate endoscopic examination and advanced imaging studies will give appropriate clinical diagnosis. Histopathology and microbiology are important for definite diagnosis.