Updated in 3/30/2010 4:12:30 AM      Viewed: 97 times      (Journal Article)
APMIS : acta pathologica, microbiologica, et immunologica Scandinavica 111 (2): 300-8 (2003)

Langerhans cell histiocytosis: an evaluation of histopathological parameters, demonstration of proliferation by Ki-67 and mitotic bodies

MI Bank , P Rengtved , H Carstensen , BL Petersen
ABSTRACT
PURPOSE: Langerhans cell histiocytosis (LCH) is a disease with a variable clinical manifestation, being localised (SS) or disseminated (MS). The etiology and pathogenesis of LCH is unknown. It is a proliferative disorder of monoclonal origin, but not necessarily neoplastic. In our study we evaluated histopathological parameters and proliferative activity in LCH. MATERIALS AND METHODS: Infiltrates from 43 patients with LCH were investigated (nSS=32, nMS=11). We evaluated different histopathological parameters semiquantitatively, demonstrating proliferation using immunohistochemistry for Ki-67. RESULTS: Overall, the histopathological picture of LCH was heterogeneous. The degree of eosinophilia and presence of necroses was significantly higher in SS-infiltrates compared to MS-infiltrates. Mitotic figures were detected in more than half the infiltrates. The Langerhans origin was verified by CD1a. Ki-67 was highly expressed in all but one infiltrate. CONCLUSIONS: The presence of necrosis and the degree of eosinophilia are related to SS-disease in our study. Ki-67 expression and the presence of mitotic figures indicate that local proliferation contributes to the accumulation of Langerhans cells. Supported by the histopathological appearance of the lesions and a level of Ki-67 expression lower than that of neoplastic tissue, we suggest that LCH is a reactive condition, possibly induced by immunostimulation caused by unknown agents.
ISSN: 0903-4641