Comparison of flowcytometry and conventional cytology for diagnosis of CNS involvement in hematologic malignancies

Introduction: Neoplastic cell infiltration into the central nervous system (CNS) is a serious complication of hematologic neoplasms. Successful management of CNS involvement requires early detection and treatment, as well as reliable criteria to evaluate the patient's treatment response. This study aimed to evaluate the agreement between flow cytometry (FCM) and conventional cytology (CC) findings for the detection of CNS involvement in hematologic malignancies. Methods: A total of 120 patients were examined in this study, including 111 patients with a previous diagnosis of hematologic malignancies and nine patients with abnormal CNS manifestations. Demographic information, including age and sex, and data on diagnosis and previous bone marrow immunophenotyping were collected for analysis. The cerebrospinal fluid (CSF) was divided into two halves; one was sent to the cytology laboratory, and the other was sent for the FCM analysis. Results: Out of 120 CSF samples evaluated in this study, the results of FCM and CC were concordant in 111 cases (79.4% agreement), including 96 FCM-/CC- and 15 FCM+/CC + cases (P