langerhans cell histiocytosis in childhood: review, symptoms in the oral cavity, differential diagnosis and report of one case

background langerhans cell histiocytosis (lch) is a rare disease in which monoclonal migration and proliferation of specific dendritic cells is seen. the disease primarily affects the bones and skin, but there is a possibility that involves other organs or appears as a multi-systemic disease. case report in oral examination of a nine-month girl, two deep wounds with a yellow membrane with approximate size of 1 × 1 cm on both sides of mandibular alveolar ridge were seen. the edges of the wounds were swollen and proliferated and redder than the surrounding mucosa. at the touch the edges of the wound were not indurated. the wound were created from the third-month and the size of wounds had become slightly larger within 6 months. according to the chronic wound and being non-responsive to various systemic and local treatments, incisional biopsy was taken from the wounds. langerhans cell histiocytosis was confirmedhistologically and immune histochemically. conclusion mouth ulcers may be the only symptoms of langerhans cell histiocytosis. therefore, the role of dentist could be important in diagnosis of this disease.