Pseudoeosinophilia on automated analyser (Sysmex XN-1000) a guide to malaria detection - An incidental finding

Rationale: Malaria is a protozoan disease which has a worldwide distribution in tropical and subtropical regions. The peripheral blood smear examination is a gold standard and an immunochromatographic rapid diagnostic test is an adjuvant diagnostic tool for the detection of malaria. For the past two decades, the utility of automated blood cell counters for the detection of malarial infection is growing in the presumptive diagnosis of malaria in developing countries. Patient Concerns: Here, we report a case in which a young male came for surgical evaluation for inguinal hernia surgery. On routine haemogram evaluation, malaria was suspected with the help of flow cytometry based haematology analyser (Sysmex XN 1000) generated histogram showing erroneously high eosinophil count (pseudoeosinophilia) and atypical white blood cell scattergram. Diagnosis: Peripheral smear and malarial antigen examinations confirmed Plasmodium vivax species. Outcomes: Patient was treated with antimalarial medications and elective surgery to repair inguinal hernia was planned after 10 days. Lessons: Here, we hope to increase the awareness of laboratory physicians to explore the possibilities of diagnosing malaria through hints provided by automated haematology analyser generated histograms.