[An unusual toothache!]. / Une douleur dentaire inhabituelle!

INTRODUCTION: Dental pain is a frequent reason for consulting. It may have non-odontogenic causes such as lesions of vascular, neurologic, muscular, or bone structures. The diagnosis and management of this acute or chronic pain syndrome may be difficult. We report a case of atypical dental pain leading to the diagnosis of a plasmocytic mandibular tumor revealing a multiple myeloma. CASE REPORT: A 50-year-old female patient consulted for dental pain during the 3 previous months. Bilateral mandibular swelling was noted during the clinical examination. Radiological examinations revealed a tumoral process associated with osteolytic lesions. The pathological examinations of biopsy samples revealed plasmocytic proliferation. A myelogram and immunoglobulin electrophoresis supported a diagnosis of multiple myeloma with kappa light chains. DISCUSSION: Discovering a mandibular tumor with lytic lesions is an indication for an etiological assessment and screening for a blood disease. A mandibular plasmacytoma may be isolated or present as a multiple myeloma, justifying a complete initial assessment. The bone localization of a plasmacytoma is a bad prognostic factor for survival for patients presenting with multiple myeloma.