Non Hodgkin lymphoma represent about 5% of childhood cancer. They are the third most common group of cancers in children and adolescents, after cerebral tumours and leukemias. They differ from adult lymphomas as they are all high grade tumours, always diffuse and often associated with extra-nodal diseases. Three main histological subtypes predominate: Burkitt, lymphoblastic and anaplastic large cell lymphomas. As the clinical progression is growing fast and treatment different between the 3 subtypes, the diagnosis must be rapidly done and with accuracy.