Langerhans Cell Histiocytosis in an Adult - a rare, life-threatening and not to be missed.

Langerhans Cell Histiocytosis (LCH) is an uncommon neoplastic disorder characterized by accumulation of histiocytes in various tissues. The clinical manifestation is highly variable, ranging from an isolated skin rash or a single bony lesion, to fatal multi-organ failure. Due to its rarity and systemic involvement, the epidemiology of LCH is still not fully understood and most studies focus on the paediatric population. The extent of clinical involvement has important prognostic implications. Treatment options may be local or systemic depending on disease extent. Here we describe a rare case of adult onset LCH who presented with recurrent pneumothoraces, diabetes insipidus and papules and plaques over the scalp and forehead.