RESUMEN
A patients with a fronto-ethmoidal mucocele secondary to fibromatosis of the nose and paranasal air sinuses is presented. The case was operated upon for first time in 1980 to remove a right fronto-ethmoidal mucocele, when a fibrous firm tissue mass was excised from the right side of his nasal cavity at the frontonasal opening. This mass was incorrectly diagnosed as fibrosarcoma. Fortunately radiotherapy was not given for fear of affecting vision. Frequent recurrences of the mucocoele with infection was treated medically and surgically. The closure of the frontonasal duct and the right upper part of nasal cavity with new bone and fibrous tissue, and the long standing condition of the patient aroused suspicion regarding the pathological diagnosis. Review of previous histopathology and fresh specimen proved that this is a case of fibromatosis of the paranasal sinuses