RESPONSE BY FLOW CYTOMETRY IN PATIENTS WITH BURKITT'S LYMPHOMA AND SECONDARY INVOLVEMENT IN THE CSF

Introduction: Central nervous system (CNS) involvement is a poor prognostic factor of non-Hodgkin's lymphoma (NHL) in children. Therefore, early diagnosis and treatment of CNS disease is important to improve long-term disease-free survival rates in children. With the continuous progress of science and technology, the methods and technologies used for the diagnosis of CNS disease are constantly improving, from imaging and cerebrospinal fluid (CSF) morphology studies to cerebrospinal fluid CSF flow pattern and genetics studies, and so on. With the continuous progress of diagnosis technology, the clinical staging of patients, which has a vital role in follow-up treatments, has also become more accurate. Most patients with early CNS invasion have no obvious clinical manifestations. Therefore, to improve the diagnostic rate of CNS invasion, flow cytometry (FC) and conventional cytomorphology (CC) of CSF were performed in newly diagnosed NHL patients for the first time of intrathecal chemotherapy. We report the examination findings and flow cytometry (FC) and conventional cytomorphology (CC) of two patients diagnosed with a Burkitt lymphoma and treatment response. Case Report: : Case 1: Adolescent, male, 16 years old, with stage IV Burkitt lymphoma. In first evaluation cerebrospinal fluid, absence of atypical cells in cytological examination, immunophenotyping, presence of 38 cells/mL with immunophenotype: CD10+, CD19+, CD20+, CD38+, CD45+, Kappa+, CD34-, Lambda-. In the second CSF, absence of atypical cells and in the immunophenotyping, absence of monoclonal B lymphoid cells. Currently, the patient is 7 months out of treatment in remission. Case 2: Adolescent, male, 17 years old, with stage IV Burkitt lymphoma; in the first evaluation of the CSF with absence of atypical cells on cytology, on immunophenotyping, presence of 40% of anomalous B cells with immunophenotype: CD10+, CD19+, strong CD20, CD34 weak, CD38 strong. In a second CSF evaluation, the patient presented absence of atypical cells on cytological examination and absence of monoclonal B lymphoid cells. Currently, the patient is undergoing treatment with no evidence of CSF involvement. Conclusion: Central invasion is more common to be found in pediatric NHL patients with bulky disease and/or BM involvement and/or involvement of more than 4 organs. It was also common in the EBV with Burkitt Lymphoma. CSF detection by FC has important clinical significance in the diagnosis of CNS invasion in children with NHL, as it can significantly improve the detection rate of CNS involvement and evaluation during the treatment.