[Langerhans cell histiocytosis of jaws: a clinical pathological and immunohistochemical study].

OBJECTIVE: To investigate the pathological and immunohistochemical characteristics of chronic localized Langerhans cell histiocytosis (LCH). METHODS: HE staining and histopathological observation, mitotic counting and immunohistochemical staining. RESULTS: 22 cases of LCH were included in this study. The most prominent histologic feature was nuclear polymorphism of Langerhans cells (LC). Nuclear sulcus was often noted. Intercellular spaces were also obvious. Mitotic figures were commonly seen (the mean mitotic index was 7.1 under 10 high magnification fields). The mean PCNA index of LC was 14.5%. Other histiocytes and multinuclear cells were CD68 and cathepsin D positive. CONCLUSION: The nuclear polymorphism of LC is of diagnostic value for LCH, LC in the lesions is hyperplastic and neoplastic in nature rather than simple accumulation and the S-100 positive LC are immature precursors of Langerhans cell.