The Placenta in Congenital Langerhans Cell Histiocytosis: A Case Report of Unusual Involvement of Chorionic Plate and Umbilical Vein.

The congenital presentation of Langerhans cell histiocytosis (LCH) is a rare presentation of an uncommon neoplastic process. Concurrent placental parenchymal involvement is even more rare, with just 2 cases of congenital multisystem LCH with placental involvement reported in English medical literature thus far. Here, we present a case of a liveborn male born at 37-weeks, 6-day gestation with congenital LCH focally involving the placenta. Langerhans cells were identified in an area of the placenta showing an unusual mononuclear cell infiltrate in the wall of the umbilical vein. Langerhans cells were also focally identified in areas of chronic villitis, as well as normal-appearing chorionic plate. The examination of the placenta in cases of clinical suspicion of LCH can be of paramount importance since it may provide the early diagnostic evidence of LCH. In this context, placental involvement by LCH should be considered even in the absence of abnormal histology.