1. Unit of Paediatric Haematology and Oncology, Department of Clinical and Experimental Medicine, Hospital Policlinico, University of Catania, Catania, Italy
2. Anatomic Pathology Section, Department of Medical, Surgical Sciences and Advanced Technologies “G.F. Ingrassia,” Hospital Policlinico, University of Catania, Catania, Italy
3. Unit of Radiology, Hospital Policlinico, University of Catania, Catania, Italy
4. Unit of Paediatric Surgery, Hospital Policlinico, University of Catania, Catania, Italy