Langerhans cells in odontogenic cysts. A retrospective study based on 142 cases.

Dendritic cells with the ultrastructural and immunocytochemical characteristics of Langerhans cells are commonly identified in lymphoid organs and in keratinized and non-keratinized epithelia, such as oral mucosa. These types of cells were previously described in the epithelial wall of periapical odontogenic cysts. S-100 protein positive cells were demonstrated immunocytochemically in all of our 142 cases of odontogenic cysts (32 developmental cysts; 110 inflammatory cysts). Their tropism for squamous epithelia may explain their presence in the epithelial wall of odontogenic cysts. Their number is not always correlated with an inflammatory condition.