Langerhans cells in odontogenic tumours and cysts as detected by S-100 protein immunohistochemistry.

Immunohistochemical demonstration of S-100 protein in Langerhans cells (LCs) was made in odontogenic epithelial tumours (71 cases), radicular cysts (40 cases), follicular cysts (28 cases), odontogenic keratocysts (11 cases), primordial cysts (7 cases) and fissual cysts (6 cases). With the use of polyclonal antiserum against S-100 protein, positive LCs, dendrical or irregular in shape were found in tumour or cystic epithelia, and sometimes in stromal connective tissue. Incidence of positive S-100 staining LCs was 11 cases out of 61 ameloblastomas, 22 cases out of 40 radicular cysts, 3 cases of 28 follicular cysts, and other lesions in both odontogenic tumours and cystic diseases lacked LCs. The cases with S-100 protein positive LCs were usually accompanied with a high degree of inflammatory infiltration in their lesions; on the contrary, the negative cases also generally lacked inflammatory responses.