Abstract
<title>Abstract</title> <p>Background: Central nervous system (CNS) involvement is a serious complication in pediatric leukemia and lymphoma, requiring accurate cerebrospinal fluid (CSF) analysis for timely diagnosis. Neubauer chamber counting is widely used but may lack sensitivity, while cytocentrifugation could improve blast detection through cell concentration. Methods: This retrospective cross-sectional study included 2,109 CSF samples from children with acute lymphoblastic leukemia (ALL), acute myeloid leukemia (AML), and non-Hodgkin lymphoma (NHL) at Bahrami Children’s Hospital, Tehran (2017–2021). Each sample was examined using both Neubauer chamber counting and cytocentrifugation. Results were categorized as positive, suspicious, or negative, and agreement was assessed with Cohen’s kappa coefficient (κ). Results: Of the total samples, 81.8% were from ALL, 8.2% from AML, and 9.8% from NHL patients. Cytocentrifugation detected 30 positive (1.4%) and 30 suspicious (1.4%) cases, while Neubauer identified only 6 positive cases (0.3%). Agreement between methods was poor (κ = 0.163, p < 0.001). Nearly 80% of positive cases by cytocentrifugation were missed by Neubauer counting. Conclusion: Cytocentrifugation is significantly more sensitive than Neubauer chamber counting for CSF blast detection in pediatric leukemia and lymphoma. Its adoption could improve early diagnosis of CNS involvement, though careful interpretation and standardized criteria are necessary to minimize false positives.</p>