Ultrastructural and morphometric study of the Langerhans cell in the normal human exocervix.

The gross morphology, density, distribution and ultrastructure of the Langerhans cell of the normal human exocervix were investigated. Two standardized zinc-iodide-osmium (ZIO) procedures were applied to epithelial sheets as well as to tissue samples processed for both light and electron microscopy. Conventional electron microscopical techniques were also used. The epithelial sheet preparation allowed the visualization of the whole profile of the Langerhans cell. It was found that the number of cell processes and the degree of their branching varied greatly from one cell to another. The cells were tentatively grouped into five types and it is suggested that they represent different degrees of cell activity. The cells appeared unevenly distributed, but with a preferential location around the external os. In the three cases studied the cell density averaged 8.3 LC/mm2. The ultrastructural study revealed the classical fine structure of the Langerhans cell. The cell processes and their branches contained all the organelles found in the perikaryon, including Golgi complexes and Langerhans cell granules. The two ZIO procedures revealed that the complex inner organization of the granule does not differ from that in the epidermal Langerhans cell. It is concluded that the Langerhans cell is a constant component of the normal human exocervix.