Immunophenotyping analysis of lymph node biopsies by flow cytometry.

T he conventional laboratory diagnosis of lymphoma using tissue biopsies is based on histology diagnosis and immunohistochemistry. However, this method is tedious and involves multiple steps and procedures. In developed countries, immunophenotyping by flow cytometry is readily performed on tissue biopsies such as lymph nodes for diagnostics purposes. However, the scenario is different in Malaysia where flow cytometric analyses of body tissues are not readily available. Fine-needle aspiration of lymph node tissues combined with flow cytometric immunophenotyping (FCI) has been reported to be successful in evaluating sites for lymphomatous involvement in 75-90% of cases. Dunphy 3 described the contribution of FCI in a series of 373 tissue specimens (278 lymph nodes and 95 extra-nodal tissue) from patients with suspected lymphoma. The results showed that the FCI data was consistent with the final tissue histological diagnosis in the majority (94%) of the tissue samples. Ravoet et al 4 evaluated the contribution of flow cytometry to the diagnosis of malignant and non malignant conditions in lymph node biopsies in 116 samples. The results showed that flow cytometric analyses of the lymph node biopsies were in agreement with tissue histology in 102 cases (87.9%). In view of the facts mentioned above, we embarked on this study to assess the role of FCI on lymph node biopsies in providing a diagnosis of hematological malignancies, especially the non Hodgkin lymphoma (NHL), in University Kebangsaan Malaysia Medical Centre (UKMMC) setting. This was a descriptive cross-sectional study of lymph node specimens from patients who were subjected to diagnostic lymph node biopsies. All lymph node specimens were processed in the Hematology and Informed consent was taken from each patient involved in this study. Patients with lymphadenopathies or with suspected hemato-lymphoid malignancies who were subjected to excisional lymph node biopsies for diagnostic purposes in UKMMC were enrolled in this study. The lymph node tissues, which were excised from patient, were cut into halves. One portion was collected into a container containing RPM1 1640 (media culture) (Logan, UT, USA) for FCI, while another portion was collected into a container containing formalin for histopathology examination (HPE). In the flow cytometry laboratory, the lymph node tissues were processed and cell suspensions were prepared. The cell suspensions were then analyzed using FACSCalibur The findings of flow cytometry analysis were compared with tissue histological diagnosis. Within the 12 months of study, only 11 lymph node biopsies were available for analysis. There were 9 males …