Langerhan cell histiocytosis: a child presenting with nine months history of fever.

We report a case of Langerhan Cell Histiocytosis in a three and a half years old child. The child presented with history of low grade fever, off and on for 9 months. There was 2 months history of progressive pallor and 5 days history of epistaxis. Blood complete picture revealed pancytopenia and the patient was referred to a paediatric oncologist. Initial diagnosis of acute lymphoblastic leukaemia (ALL), Lymphoma and disseminated Tuberculosis (TB) was made on basis of initial investigations. Coetaneous involvement occurred 7 months later along with Diabetes Insipidis, bone changes and pulmonary involvement.