RESUMEN

INTRODUCTION AND IMPORTANCE: Langerhans cell histiocytosis (LCH) is a proliferation of dendritic mononuclear cells with infiltration into organs locally or diffusely. Its aetiology is still unknown, and its clinical spectrum is quite wide. CASE PRESENTATION: A 2-year-old-male child presented to us with a solitary swelling in left mandibular region which was painless and increasing in size with time. It was diagnosed to be unifocal LCH of mandible on the basis of X-ray, ultrasonography of the involved mandible and fine needle aspiration cytology of the swelling and managed conservatively with oral steroids. DISCUSSION: LCH is often classified as single system, when the disease affects only one part of the body; or multisystem, when it affects more than one part of the body (Jezierska et al., 2018 [1]). In children, histiocytosis usually involves the bones and may consist of single or multiple sites. The skull is frequently affected. Children over five years of age usually have the single system disease, with just bone involvement but our patient was 2-year-old and had unifocal disease involving mandible. Young children, especially infants, are more likely to have the multisystem disease (Jezierska et al., 2018 [1]). CONCLUSION: Mandibular involvement associated with LCH is quite uncommon in paediatric population. Early diagnosis and prompt initiation of treatment are key to a good eventual outcome.