Prevalenceand diagnostic utility of cytochemical staining versus immunophenotyping in pediatric acute leukemia: a retrospective study at Siriraj Hospital

Objective: This study evaluated the prevalence of acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) among pediatric patients at Siriraj Hospital and compared the diagnostic effectiveness of cytochemical staining and immunophenotyping. Materials and Methods: A retrospective review was conducted on 302 pediatric patients (0–18 years) diagnosed with acute leukemia from 2008 to 2021. The prevalence of ALL and AML was determined, and hematologic parameters were analyzed. The sensitivity, specificity and predictive values of cytochemical stains were compared with those of immunophenotyping. Results: Among 302 cases (176 males, 126 females), ALL was the predominant diagnosis (76.5%), with 69.2% classified as B-cell ALL (B-ALL) and 7.3% as T-cell ALL (T-ALL). AML accounted for 23.5%. Patients with T-ALL were significantly older (p <0.01) and had higher hemoglobin (p = 0.044) and white blood cell counts (p = 0.012) compared with patients with AML and B-ALL. Cytochemical stains demonstrated variable utility across leukemia subtypes. Myeloperoxidase (MPO) and Sudan Black B (SBB) showed high diagnostic accuracy for AML, with sensitivities of 74.51% and 85.92% and specificities of 100%. PAS staining had a high PPV (89.94%) for B-ALL but was less sensitive for T-ALL (50%). Conclusion: Cytochemical staining serves as a valuable complementary diagnostic tool for acute leukemia. Integrating PAS and MPO staining can enhance preliminary leukemia subtyping, especially in resource-limited settings. This approach facilitates timely and accurate diagnosis, supporting early treatment initiation and improving outcomes for pediatric patients.