The paper presents diagnostic and therapeutic difficulties in two adolescents with widespread rhabdomyosarcoma (RMS) presenting with severe haemorrhages resulting from disseminated intravascular coagulation (DIC) and with laboratory features of acute tumour lysis syndrome (ATLS). Other published cases of childhood RMS with DIC at admission have been listed and reviewed. It has been concluded that the clinical picture of a widespread RMS in children may resemble acute hematologic malignancy and pose a big diagnostic problem. That is why the presence of small blue round cells morphologically similar to lymphoblasts and/or myeloblasts in bone marrow (BM), lacking hematopoietic makers, should prompt the pathologist to consider possible diagnosis of RMS. Inclusion of desmin, MyoD1 and myogenin Myf4 to the immunohistochemical panel is obligatory in such cases. When the representative histopathological tumour specimens are difficult to obtain, the flow cytometric immunophenotyping of BM metastases could help the standard morphological/immunohistological diagnostic procedures and advance the diagnosis. Recently, the flow cytometric CD45− CD56+ immunophenotype together with Myf4 transcript has been assigned to RMS cells infiltrating BM. In children with disseminated RMS complicated with DIC rapid polychemotherapy aimed at diminishing the malignancy-triggered procoagulant activity should be initiated. However, in cases with concomitant ATLS the initial doses of chemotherapy should be reduced and the metabolic disorders and renal function monitored. The prognosis in children with RMS metastatic to BM with signs of DIC or ATLS at admission depends on the response to chemotherapy, however generally it is highly disappointing.

Nijmegen breakage syndrome (NBS) is a human autosomal recessive disease characterized by genomic instability and enhanced cancer predisposition, in particular to lymphoma and leukemia. Recently, significantly higher frequencies of heterozygous carriers of the Slavic founder NBS1 mutation, 657del5, were found in Russian children with sporadic lymphoid malignancies, and in Polish adults with non-Hodgkin lymphoma (NHL). In addition, the substitution 643C>T (R215W) has also been found in excess among children with acute lymphoblastic leukemia (ALL). In an attempt to asses the contribution of both mutations to the development of sporadic lymphoid malignancies, we analyzed DNA samples from a large group of Polish pediatric patients. The NBS1 mutation 657del5 on one allele was found in 3 of 270 patients with ALL and 2 of 212 children and adolescents with NHL; no carrier was found among 63 patients with Hodgkin lymphoma (HL). No carriers of the variant R215W were detected in any studied group. The relative frequency of the 657del5 mutation was calculated from a total of 6,984 controls matched by place of patient residence, of whom 42 were found to be carriers (frequency 5 0.006). In the analyzed population with malignancies, an increased odds ratio for the occurrence of mutation 657del5 was found in comparison with the control Polish population (OR range 1.48-1.85, 95% confidence interval 1.18-2.65). This finding indicates that the frequency of the mutation carriers was indeed increased in patients with ALL and NHL (p < 0.05). Nonetheless, NBS1 gene heterozygosity is not a major risk factor for lymphoid malignancies in childhood and adolescence. ' 2005 Wiley-Liss, Inc.Key words: lymphoid tissue malignancies; childhood and adolescence; NBS1 gene; 657del5 mutation; Nijmegen breakage syndrome Nijmegen breakage syndrome (NBS) (OMIM *251260) is a human autosomal recessive disease characterized by microcephaly, immunodeficiency, hypersensitivity to ionizing radiation and a very high incidence of cancer, particularly of lymphoid origin.1,2 The disease seems to be more prevalent among Central and Eastern European populations, with Polish patients constituting approximately half of all registered NBS patients worldwide. The great majority of NBS patients (>90%) share a pathogenic truncating mutation, 657del5, within exon 6 of the NBS1 gene. 3The NBS1 gene encodes a protein called nibrin or p95NBS1, which forms a multimeric complex with hMRE11 and hRAD50 (N/M/R complex) involved in recombination repair of DNA double-strand breaks (DNA DSBs) in yeast and mammals.3,4 DNA DSBs occur as intermediates in physiological events, such as V(D)J recombination during early B and T cell development and immunoglobulin (Ig) class switch in mature B cells, but most frequently are generated by mutagenic agents such as ionizing radiation and radio-mimetic chemicals. DNA DSBs represent the most serious DNA damage, which, if not repaired accurately, can result in genomic instability, including chromosome rearrangements or gene mutations, and finally...

BackgroundSince 1983 four consecutive unified regimens: acute myeloid leukemia-Polish pediatric leukemia/lymphoma study group (AML-PPLLSG) 83, AML-PPLLSG 94, AML-PPLLSG 98 and AML-BFM 2004 Interim, for AML have been conducted by the Polish Pediatric Leukemia/Lymphoma Study Group (PPLLSG). In this paper, we review four successive studies on the basis of acute myeloid leukemia-Berlin–Frankfurt–Munster (AML-BFM) protocol, in which a stepwise improvement of treatment outcome was observed. Treatment results of the last protocol AML-BFM 2004 Interim are presented in detail.MethodsThree hundred and three patients with de novo AML were treated according to the AML-BFM 2004 Interim at 15 Polish centers from January 1, 2005 to June 30, 2011. A confrontation with previous treatment periods was based upon historical, already published data.ResultsIn four consecutive periods, 723 children were eligible for evaluation (208, 83, 195, and 237, respectively). Complete remission rates in consecutive periods were: 71, 68, 81 and 87 %, respectively. The 5-year overall survival rates, event-free survival rates, and relapse-free survival rates were 33, 32, and 45%, respectively for AML-PPLLSG 83 regimen; 38, 36, and 53 % respectively for AML-PPLLSG 94 regimen; 53, 46, and 65 % respectively for AML-PPLLSG 98 regimen, and 63, 52, and 64 % for AML–BFM Interim 2004, respectively. Incidence of early deaths and that due to complications (mainly infections) in the first remission decreased over time from 22 to 4.6 % and from 10 to 5.9 %, respectively.ConclusionsDespite continuous improvement in the treatment outcome, the number of failures still remains too high. Further progress seemed to be possible due to continued cooperation of oncology centers within large international study groups.

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Aim of the studyRecent studies showed relatively better outcome for children with refractory (refAML) and relapsed acute myeloid leukemia (relAML). Treatment of these patients has not been unified within Polish Pediatric Leukemia/Lymphoma Study Group (PPLLSG) so far. The goal of this study is to analyze the results of this therapy performed between 2005–2011.Material and methodsThe outcome data of 16 patients with refAML and 62 with relAML were analyzed retrospectively. Reinduction was usually based on idarubicine, fludarabine and cytarabine with allogenic hematopoietic stem cell transplant (alloHSCT) in 5 refAML and 30 relAML children.ResultsSeventy seven percent relAML patients entered second complete remission (CR2). Five-year OS and disease-free survival (DFS) were estimated at 16% and 30%. The outcome for patients after alloHSCT in CR2 (63%) was better than that of those not transplanted (36%) with 5-year OS of 34% vs. 2-year of 7% and 5-year DFS of 40% vs. 12.5%. Second complete remission achievement and alloHSCT were the most significant predictors of better prognosis (p = 0.000 and p = 0.024). The outcome of refAML children was significantly worse than relAML with first remission (CR1) rate of 33%, OS and DFS of 25% at 3 years and 53% at 2 years, respectively. All survivors of refAML were treated with alloHSCT after CR1.ConclusionsThe uniform reinduction regimen of the documented efficacy and subsequent alloHSCT in remission is needed to improve the outcome for ref/relAML children treated within PPLLSG. The focus should be on the future risk-directed both front and second line AML therapy.