[Mandibular desmoplastic fibroma: diagnosis and therapeutics difficulties].

INTRODUCTION: The desmoplastic fibroma is a rare bone tumor, characterized by aggressive local infiltration, with frequent recurrence. The most common site is the mandible. Radioclinical signs are not specific and the histological diagnosis may be difficult. CASE: A 16 year-old male patient consulted for a painless and hard left mandibular swelling, without inferior alveolar nerve disorders. The tumor extended from tooth 31 to tooth 35, the mucosa was healthy. The panoramic view showed a multilocular osteolytic lesion with dental root resorption. CT scan showed expansion of bony cortex with rupture of the outer cortical. The biopsy indicated a desmoplastic fibroma or a fibrosarcoma. A second histological analysis combined with an immuno-histochemical study proved the diagnosis of desmoplastic fibroma. DISCUSSION: The desmoplastic fibroma has a polymorphous symptomatology. Radiological signs are unspecific. Anatomopathology combined with immuno-histochemistry can prove the diagnosis and guide the treatment.