Thrombocytosis in children

We aimed to investigate the frequency and causes of thrombocytosis in patients admitted to the Department of Pediatric Hematology and Oncology of Elazig Fethi Sekin City Hospital, Elazig, Turkey.Between 2019 and 2021, the laboratory parameters of 2,500 patients admitted to the Hematology Department were studied. During this examination, 319 (12.76%) patients were found to have thrombocytosis. Demographic characteristics (age and gender), hematologic parameters (hemoglobin, white blood cells, and platelets), and ultimate diagnoses ot the cases were recorded from their files.Of these 319 patients with thrombocytosis, 197 (1.8%) were male and 122 (38.2%) were female, and the mean age was 72.0±69.0 (1-216) months. The median platelet count of the patients was 590.43±280.12/μL (450,000-750,000). The most common cause of secondary thrombocytosis was infection, accounting for 37.9% of all patients. Other common causes were sickle cell anemia (21%), iron deficiency anemia (15.4%), colloid tissue disease (6.6%), hemolytic anemia (5.0%), splenectomy (4.5%), and other causes (9.7%).In our study, infections were the most common cause of thrombocytosis. In addition to infections, sickle cell anemia and iron deficiency anemia should also be considered in the differential diagnosis of thrombocytosis.