Balcerska A, Godziński J, Bień E, et al. Rare tumours – are they really rare in the Polish children population? Przegl Lek. 2004;61 Suppl 2:57-61 Benesch M, Wardelmann E, Ferrari A, et al. Gastrointestinal stromal tumors (GIST) in children and adolescents: a...