Abstract
A newborn girl had papular eruptions on the trunk and extremities at birth. The cutaneous lesions changed to blisters and crusts the next day. At her initial visit, scattered pale brownish crusts and papules were present on the trunk and extremities.
Histopathological analysis revealed infiltrative proliferation of histiocyte-like mononuclear cells whose nucleus appears kidney-shaped in the upper dermal layer.
The tumor cells were positively stained with S100 protein, CD1a, and langerin. We initially suspected congenital self-healing reticulohistiocytosis because of the characteristic rash, but we diagnosed Langerhans cell histiocytosis (multi-system multi-site type) on the grounds of an enlarged thymus and lung involvement on a chest computed tomography scan. The rash and lung involvement disappeared after administration of prednisolone. We administered multidrug chemotherapy four months after birth. Her thymus tended to shrink over time but we started re-induction chemotherapy because it began to increase in size again.
