FSCN1 and juvenile xanthogranuloma: Juvenile xanthogranuloma (JXG) is a rare non-Langerhans cell (LCH) histiocytic disorder with histologic features characteristic of dermal dendrocytes (fascin+, CD1a−, CD207−) and macrophages (CD14+, CD68+, CD163+, and factor XIIIa+) [1].