Role of Gray Scattergram in Detecting Blasts Compared with Microscopic Peripheral Smear in Acute Leukemia Patients

Early and accurate diagnosis of acute leukemia is essential for timely treatment and improved patient outcomes. Gray scattergram patterns generated by hematology analyzers may indicate the presence of blasts and serve as an early screening tool. This study evaluated the correlation and agreement between gray scattergram findings and microscopic detection of blasts on peripheral blood smears in newly diagnosed acute leukemia patients.

This retrospective cross-sectional study used secondary data from inpatients with acute leukemia treated at Dr. Hasan Sadikin General Hospital between April 2024 and March 2025. Diagnoses were identified using ICD-10 codes for acute lymphoblastic leukemia and acute myeloid leukemia. Eligible patients had complete hematological data at diagnosis, including complete blood count and peripheral blood smear results. Collected variables included demographic characteristics, hematological parameters, peripheral blood blast percentage, analyzer-generated flags, and scattergram findings. Leukocyte differential counts and blast percentages were validated by manual microscopic examination. Scattergram findings were classified as gray or non-gray, with gray defined by the presence of ≥35.5% blasts. Agreement between gray scattergram findings and microscopic blast detection was analyzed using Cohen's kappa statistic. However, the moderate level of agreement indicates that gray scattergram findings should be interpreted cautiously and require confirmation by microscopic examination.

A total of 106 patients were included. Gray scattergram findings were observed in 66 patients, of whom 52 (83.9%) had ≥35.5% blasts on microscopic examination. Among non-gray scattergram cases, 10 patients (16.1%) also showed blast counts ≥35.5%. Agreement between gray scattergram findings and microscopic blast identification was moderate (κ=0.527, p<0.001).

Gray scattergrams may provide early indications of blast presence and serve as a supportive screening tool in suspected acute leukemia. However, confirmation by peripheral blood smear or bone marrow examination remains necessary in clinical settings.