Langerhans cells week 26

Langerhans cells increase in numbers

The density of Langerhans cells in the embryonic epidermis is 10-20% of the density in adult epidermis, or about 65 cells/mm2. Nevertheless these cells are an expanding population as their numbers must keep pace with the rapidly expanding surface area of the fetus in order to maintain the same density. By about the 20th week of gestation, the density of Langerhans cells is about the same as in embryonic epidermis, but then the density increases by 2-fold over the next four weeks and continues to increase for the remainder of gestation and into the neonatal period.