Langerhans cell histiocytosis with presentation as orbital disease.

Langerhans cell histiocytosis (LCH) is an uncommon multisystem disease with an abnormal polyclonal proliferation of Langerhans cells that invade various organs. In rare instances, the affection of the orbit is the only and the first symptom. We report an unusual case of an 18-month-old male who presented with orbital disease as the first symptom, in the form of chronic presentation of periorbital swelling (2 months duration) with acute inflammation (1-week duration) giving a suspicion of orbital cellulitis. Histopathology after radical excision confirmed the diagnosis of LCH and was advised initial therapy as per Histiocyte Society Evaluation and Treatment Guidelines (2009) but was lost to follow-up only reappearing with progression (multisystem LCH with risk organ involvement) and developed progressive active disease on treatment after 5 weeks. He was treated with salvage therapy for risk patients achieving complete remission.