Precursor B-cell lymphoblastic lymphoma in childhood and adolescence: Clinical features, treatment, and results in trials NHL-BFM 86 and 90

Background Precursor B‐cell lymphoblastic lymphoma (PBLL) is a rare subtype of childhood non‐Hodgkin lymphoma (NHL). The purpose of our study was to investigate frequency and clinicopathological features of PBLL in children and to test prospectively the efficacy of an ALL‐type therapy for treatment of these patients. Procedure From October, 1986, to March, 1995, 1,075 patients up to 18 years of age suffering from all kinds of NHL were registered in the two consecutive multicenter studies NHL‐BFM 86 and 90. Of these, 27 patients were diagnosed with PBLL. Twenty‐one PBLL patients were treated according to a BFM‐ALL‐type protocol: an eight‐drug induction over 9 weeks was followed by an 8‐week consolidation including methotrexate 5 g/m2 ×4. Patients in stages I and II continued with maintenance up to a total therapy duration of 24 months, whereas patients in stages III and IV received an additional eight‐drug intensification and cranial radiotherapy (12 Gy for prophylaxis) after consolidation. Six PBLL patients were treated according to the BFM‐protocol for B‐NHL, stratified according to stage and tumor load and consisiting of two to six 5‐day courses of chemotherapy. Results The median age of the 27 patients with PBLL (18 boys, 9 girls) was 6.2 (range 0.7–15) years. Stages (St. Jude) were: I (n = 3), II (n = 7), III (n = 9), and IV (n = 8). Twenty‐one PBLL patients had nodal disease, 6 patients had subcutaneous manifestations, and 8 patients had bone marrow disease (