Inverted papilloma: a study of 13 cases in the Oto-Rhino-Laryngoiogy at the National University Hospital of Fann

Introduction: Inverted Papilloma (IP) is a rare benign tumour of the nose and paranasal sinuses histologically characterized by invagination of the outer layer of the epithelium in the underlying chorion. Its most distinctive feature is a strong local aggressiveness, a tendency to recur and an unpredictable risk of association with epidermoid carcinoma. The purpose of this study was to report the epidemiological, clinical, paraclinical data as well as to assess the outcomes of endoscopic endonasal surgery. Methods: we conducted a retrospective study on a series of 13 patients whose data were collected in the Oto-Rhino-Laryngology at the National University Hospital Center of Fann, from 1st January 2012 to 31st December 2017. All patients followed up for inverted papilloma confirmed by anathomopathological examination were included in the study. Results: the average age of patients was 44 years, the sex-ratio was 2.25. All patients had nasal obstruction; 53% of them had rhinorrhea followed by epistaxis in 30% of cases. Right-sided symptoms were reported by 69% of patients, left-sided symptoms by 23% and bilateral symptoms by 7% of patients. Anterior rhinoscopy showed endonasal mass in all patients. All patients underwent CT scan; the MRI was performed in a single patient. Endoscopic resection of IP was performed in 10 patients (76.9%) while external approach was used in 23% of cases. Surgery helped to clarify where the tumor had originated: in 46% of cases in the maxillary sinus, in 15% in the lower nasal turbinate, in 15% in the mid-turbinate, in 7% in the ethmoid butte and in 7% in the lateral wall of the nasal fosse. One patient had recurrence after an average period of 26 months. Malignant transformation to squamous cell carcinoma occurred in one patient. Conclusion: inverted papilloma is a very aggressive tumor. CT scan is essential to highlight its spread, especially to bone. The advent of endoscopic surgery has revolutionised treatment, providing excellent results. But, there is nevertheless a risk of recurrence after surgery which motivates an indication for long term monitoring.