title: Lower proliferation rate in metastatic effusion mesothelial cells than in benign effusions.
abstract: OBJECTIVE
  To determine the proliferation rates of mesothelial cells in metastatic and benign effusions.
  
  
  METHODS
  Immunohistochemistry was performed on formalin-fixed pellets from 16 malignant and 9 benign clinical effusions. Dual staining with antibodies against Ki-67 (MIB-1) and desmin was applied to all effusions to differentiate between benign mesothelial cells and malignant cells, and the proportions of desmin+/Ki-67+ and desmin+/Ki-67- cells were calculated.
  
  
  RESULTS
  In 7 malignant effusions no proliferating mesothelial cells were found, whereas some rate of proliferation could always be demonstrated in mesothelial cells in the benign effusions. Further, the median proportions of proliferating cells, malignant 2% vs. benign 11%, differed significantly.
  
  
  CONCLUSIONS
  To our knowledge this finding has not been previously described, and it may have implications for both cytologic diagnosis and the understanding of tumor biology and the interaction between tumor cells and mesothelial cells.
authors: Department of Laboratory Medicine, Section of Pathology, Malmö University Hospital, Lund University, Malmö, Sweden.
authors: Johanna
authors: J
authors: Rehnberg
authors: Nooreldin
authors: N
authors: Zendehrokh
authors: Annika
authors: A
authors: Dejmek
mesh_terms: D001202:Ascitic Fluid / Q000378:metabolism / Q000473:pathology*; D014408:Biomarkers, Tumor / Q000378:metabolism; D049109:Cell Proliferation; D003893:Desmin / Q000378:metabolism; D004848:Epithelium / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D019394:Ki-67 Antigen / Q000378:metabolism; D016066:Pleural Effusion, Malignant / Q000378:metabolism / Q000473:pathology*; D010997:Pleural Neoplasms / Q000378:metabolism / Q000556:secondary*
chemical_list: D014408:Biomarkers, Tumor; D003893:Desmin; D019394:Ki-67 Antigen