Clinical spectrum of cutaneous Langerhans' cell histiocytosis mimicking various diseases.

Langerhans' cell histiocytosis summarizes a spectrum of diseases on the basis of histogenetic criteria. These are characterized by an accumulation of cells with Langerhans' cell phenotype in one or multiple organs. Up to 50% of patients with either single or multi-organ manifestation of Langerhans' cell histiocytosis initially present with cutaneous symptoms. Nevertheless, cutaneous Langerhans' cell histiocytosis is rare and heterogeneous in its clinical features and therefore prone to misdiagnosis. We report on five patients, two infants and three adults, suffering from cutaneous Langerhans' cell histiocytosis, either singly or as part of multi-organ disease. The different skin features morphologically mimicking other entities are shown and the differential diagnoses are discussed. The correct diagnosis in all presented cases is based on immunohistological examination, showing a histiocytic infiltrate positively staining with anti-S100 antibodies, CD1a and--apart from one case--with CD207 (langerin).