Detection of micrometastases in mediastinal lymph nodes by haematological analyser and flow cytometry-pilot study.

Abstract

The presence of metastases in mediastinal lymph nodes (LNs) is crucial in planning treatment of lung cancer. This is also a place of activation of anticancer immune response. The aim of the study was to assess LNs for the presence of neoplastic cells and to determine the expression of selected lung cancer antigens. LNs aspirates were obtained during EBUS/TBNA procedure. The cells were analysed by haematological analyser and flow cytometry. It was possible to indicate the presence of cells characterized by high fluorescence connected with high metabolic activity using a haematological analyser (Figure 1A. Dot plots with cancer cells- green) and to determine their non-haematopoietic origin using flow cytometry (Figure 1B). Using these methods we detected very quickly high proportion of cancer cells (80%) in LNs. We noticed that it was possible to determine expression of selected antigens on cancer cells: cytokeratin, EpCAM, CD184, CD31, CD71 and Ki67 (Figure 1C) . We report for the first-time that detection of tumor cells in LNs with expression of specific antigens is easy to evaluate by haematological analyser and flow cytometry in EBUS-TBNA samples. Such a precise characteristics of non-hematopoietic cells in LNs may be of great diagnostic importance in the detection of micrometastases.