A pathologic mandibular fracture revealing a bifocal location of Langerhans cell histiocytosis

Introduction: Langerhans cell histiocytosis is a rare disease. When it occurs in the cranium/facial bones, the mandibular location is the most frequent. Presentation of case: A 31 years-old man was referred to our department for a mandibular chronic discomfort during an acute exacerbation, spontaneous teeth mobility and an alteration of the dental occlusion revealing a pathologic mandibular fracture. The diagnosis was confirmed by a subsequent CT scan. The surgical procedure was performed under general anesthesia by a maxillo-facial senior surgeon. The therapeutic plan combined teeth extractions, enucleation of both the left maxillary and right mandibular cystic lesions and osteosynthesis of the pathologic mandibular fracture with a miniplate. Histological and immunohistochemistry analysis of the maxillary and mandibular cystic lesions pointed the diagnosis of a bifocal Langerhans cell histiocytosis of the oral cavity. Several investigations were done in order to find another location, showing no abnormalities. Discussion: This is a case of rare single system LCH at two distinct locations: one at the mandibular bone and the other at the upper left maxilla. Both were uncovered by an acute exacerbation of a chronic discomfort secondary to a mandibular pathologic fracture. This should draw attention to the issues of the diagnosis. Conclusion: An early LCH diagnosis and a multidisciplinary treatment plan allow the improvement of the patient ‘s prognosis and quality of life.