1. Department of Pathomorphology, Medical University of Gdansk, Gdansk, Poland
2. Department of Pediatrics, Hematology and Oncology,
Medical University of Gdansk, Gdansk, Poland
3. The English Division Pediatric Oncology Scientific Circle, Medical University of Gdansk, Gdansk, Poland
4. Coronary Care Unit, Cardiology Department, West Cumberland Hospital, Whitehaven, United Kingdom
5. Department of Pediatrics, Oncology and Hematology, Medical University of Warsaw, Warsaw, Poland
6. Department of Pediatrics, Paediatric Oncology, and Hematology, Medical University of Bialystok, Bialystok, Poland