Backscatter electron imaging of cells from effusions.
Cells from body cavity effusions from 35 patients were examined by scanning electron microscopy using both secondary electron imaging and backscatter electron imaging (BEI). This technique allows simultaneous viewing of the same cell for histological identification and for surface configuration. Mesothelial cells, macrophages, lymphocytes, neutrophils and malignant cells could be identified by their nuclear details and their surface features. Mesothelial cells had either smooth surfaces or blebs with few microvilli. Lymphocytes and neutrophils had similar surface features but could be easily identified by BEI. Macrophages had lamellar cytoplasm. Malignant cells were usually large and occurred singly or more frequently in groups. Their irregular chromatin pattern was easily recognized by BEI and was clearly different from mesothelial cells. This technique uses micropore filters to collect the cells. It is a rapid and simple procedure which offers advantages over previously described techniques using glass coverslips.