Hodgkin and Non-Hodgkin Lymphoma: Flowcytometric Immunophenotyping on Fine Needle Aspirate of Lymph Node

Introduction: Hodgkin and Non-Hodgkin lymphoma (NHL) differ substantially in response to therapy and course. So accurate differentiation is important for therapeutic decision. Objective: The aim of this study was to evaluate the application of flow cytometry in diagnosis of Hodgkin and Non--Hodgkin lymphoma on fine needle aspirate (FNA) of lymph node by following immunophenotypic diagnostic criteria based on expression of CD markers. Method: Fine needle aspiration cytology (FNAC) was done on 40 clinically suspected lymphoma cases. If atypical lymphocytes were present FCI was performed with a complete panel of monoclonal antibodies (CD3,CD4,CD8,CD5,CD7,CD10,CD19,CD20,CD22,CD23,CD25,CD30,CD45,CD79a,CD79b,CD95,FMC7,CD40,CD15,CD56, Kappa, Lambda and Bcl-2) by dual flow color cytometry. FCI data were interpreted to diagnose lymphoma according to WHO classification. Wherever possible the diagnosis was compared with available histopathology and immunohistochemistry (IHC) reports. Result: Out of 40 cases, 32 (80%) cases were diagnosed and characterized as lymphoma. Among 32 cases, 31 (96.9%) cases were Non-Hodgkin lymphoma (NHL) and 1 (3.1%) case was Hodgkin lymphoma (HL). Among 29 histopathology reports available, comparison between FCI and histopathology showed concordance (both complete and partial) in 13 (44.8%) cases and discordance in 16 (55.2%) cases. Among 17 immunohistochemistry (IHC) reports available, comparison between FCI and IHC showed concordance (both complete and partial) in 12 (70.6%) cases and discordance in 5 (29.4%) cases. Conclusion: FCI from FNA sample can enhance the diagnostic potential and avoid the need for invasive surgical biopsies. Moreover, it can diagnose more Non-Hodgkin lymphoma than Hodgkin lymphoma.