Langerhans Cell Histiocytosis of the Orbit Presenting as Periorbital Cellulitis.

Langerhans cell histiocytosis (LCH) is a rare disease of the reticuloendothelial system. It is characterized by misguided differentiation of myeloid dendritic cell precursors. LCH most commonly presents in childhood and the clinical presentation is dependent on the site and extent of organ involvement. We report a case of orbital Langerhans cell histiocytosis in a 12-year-old boy who presented with left periorbital cellulitis with subsequent proptosis. He later underwent a successful left orbital-frontal-temporal craniotomy and is currently undergoing postoperative chemotherapy.