Langerhans cell density in epithelial skin tumors correlates with epithelial differentiation but not with the peritumoral infiltrate.

We investigated the intraepithelial density of Langerhans cells in 17 epithelial skin tumors by immunohistologic and morphometric methods. There was a significant difference between seborrheic keratosis (Langerhans cell density 431 +/- 31/mm2; normal epidermis: 378 +/- 20/mm2), basal cell carcinoma (28 +/- 6/mm2), and squamous cell carcinoma (100 +/- 21/mm2). No correlation was found between the Langerhans cell density and the number of intraepithelial T lymphocytes or the extent of the peritumoral inflammatory infiltrate. A significant inverse correlation was demonstrated between mean nuclear area of the epithelial tissue and the Langerhans cell density (r = -0.7; p less than 0.05). These data indicate that the number of Langerhans cells does not influence the extent of the antitumoral immune response. The correlation with the level of epithelial differentiation may be due to different homing conditions.