Objectives: The aim of this study is to report our cases of isolated frontal sinus aspergilloma (FSA), and identify key features and aspects suggestive of this pathology. Moreover, we have investigated the pathogenesis of this FSA, which has not been clearly elucidated yet. Materials and Methods: A retrospective study on cases of isolated FSA treated at the unit of Otolaryngology of the Hopital Lariboisière in Paris from 2009 to 2023 was performed. A chart review was done, Demographic and radiologic data, type of treatment with intraoperative findings, and follow-up were analyzed. Moreover, a literature review was carried out on Pubmed and Scopus using the search terms “frontal sinus aspergilloma”, “frontal sinus fungus ball” and “frontal sinus mycetoma”. Non-invasive FSA characteristics, especially the relation with surrounding bony structures were analyzed. Results: Six patients were included. The median age of the patients was 58 years old (range 25-69); 2/6 patients were female. The most common symptom was headache. All the patients underwent exclusive endoscopic sinus surgery. With regards to literature review, 17 papers have been identified reporting a total number of 30 cases of FSA. Overall, frontal sinus walls erosion was described in 47% of the cases showing a prevalence of erosive behavior of this pathology. Conclusions: FSA shows a higher incidence of bone erosion compared to other PSA. The destructive behavior of FSA could increase the risk of potential intracranial and intraorbital complications. Recognizing the radiological features of FSA, is crucial for accurate differential diagnosis with invasive forms of fungal infections and treatment planning.

Keypoints and Key wordsKeypoints :Many reports suggest that odontogenic sinusitis cause critical orbital abscess with high risk of ophthalmologic sequelae due to the pathogenic potential of anaerobic bacteria.This study aimed to compare the outcomes between odontogenic sinusitis and non-odontogenic sinusitis after management of orbital abscess in an adult population.The rates of revision surgery and visual sequelae were significantly higher in the odontogenic sinusitis group.Dental etiology of the sinusitis was overlooked in four patients (24%) of the odontogenic sinusitis group. Hence, dental cause of sinusitis has to be systematically sought and treated.Key words: Abscess, Blindness, Odontogenic infection, Orbital cellulitis, Sinusitis.Ethical considerationsThe protocol was approved by the local ethics committee. All participants gave informed consent.Main TextINTRODUCTIONOrbital cellulitis is a rare acute infection of the orbit and its contents that occurs mostly in children. The main cause is sinusitis (1). It is usually classified according to Chandler’s classification based on location and severity (2). Among orbital cellulitis, abscess formation occurs in 30% of the patients (3). Associated neurological acute complications, such as empyema or cerebral abscess, are rare but life-threatening. Long-term complications can be dramatic, notably blindness and cosmetic sequelae. The treatment includes hospitalization, intravenous antibiotics and surgery. The surgical procedure can combine endoscopic endonasal approach and external approach.According to the scientific literature, only 10% of sinusitis are odontogenic (4). Some authors suggest that odontogenic sinusitis (OS) cause critical orbital abscess (5) with higher risk of ophthalmologic sequelae (6), due to the pathogenic potential of anaerobic bacteria.This study aimed to compare the outcomes between OS and non-OS after management of orbital abscess in an adult population.MATERIALS AND METHODS