Juvenile xanthogranuloma versus Langerhans cell histiocytosis (Histiocytosis X)

THE HISTOLOGICAL DIFFERENTIAL diagnosis of juvenile xanthogranuloma (JXG) includes Langerhans cell histiocytosis (LCH; Histiocytosis X). Making the distinction between these conditions is often important clinically and can usually be reliably accomplished histologically. This article will focus on how the distinction between these conditions can be made. To do this, first we will describe the "classic" features of both conditions (in which case distinction is usually straightforward) and then we will describe less classic features, which can lead to more difficulty in establishing a diagnosis. We will close with a brief discussion of other conditions that need to be considered in the differential diagnosis.