Abstract:

Desmoplastic fibroma （DF） is an extremely rare benign tumor of the jaw bone. Due to its lack of distinct specific features， it is often difficult to distinguish clinically from other diseases， which can lead to suboptimal therapeutic outcomes and increased treatment complexity. This article reportsed the clinical features of an elderly patient with DF to provide the reference for its diagnosis and treatment. The patient， a 66-year-old female， was admitted to the hospital due to recurrent swelling and discomfort in the left posterior mandibular region for over 20 years. The physical examination results showed a hard， tender bony expansion in the left posterior mandible. The panoramic radiography and cone-beam computed tomography （CBCT） results showed an ill-defined radiolucent shadow， about 1.5 cm×1.8 cm， and bone destruction. To confirm the diagnosis， a preoperative pathological biopsy was performed， which showed a spindle cell lesion with a background of abundant fibrous connective tissue. Based on the above findings， the definitive diagnosis of mandibular DF was made. Given the aggressive nature of DF， the lesion was resected via partial mandibulectomy. The defect was repaired using a reconstruction plate for internal fixation and a submandibular gland flap. The postoperative pathology examination results showed dense fibrous connective tissue， with some cellular components exhibiting atypia and the presence of some mast cells， consistent with the pathological characteristics of DF. No postoperative complications or recurrence were observed during the 1-year follow-up period. DF often lacks specific features， which results in the difficulties in diagnosis and treatment. Comprehensive diagnosis requires the integration of imaging and pathological examinations， and treatment involves surgical resection with wide margins. Although DF is typically benign， it exhibits local aggressiveness， necessitating postoperative observation and follow-up for the patients.

Key words: Mandible, Desmoplastic fibroma, Partial mandibulectomy, Benign tumor of mandible, Flap repair, Case report