Cristina Rosanda

Detection of Neuroblastoma Cells in Bone Marrow and Peripheral Blood by Different Techniques Accuracy and Relationship with Clinical Features of Patients

Purpose: Detection of metastatic tumor cells in bone marrow (BM) and peripheral blood (PB) of children with neuroblastoma is crucial for prognosis and planning of therapy. Aims of this large descriptive repeated survey were to evaluate the diagnostic accuracy of different techniques in diagnostic samples obtained at several disease course time points and to correlate positive results with patient clinical features and outcome. Experimental Design: BM aspirates, trephine biopsies, PB, and peripheral blood stem cell (PBSC) samples from Italian children with neuroblastoma were analyzed by morphological and histologic techniques, as well as by immunocytochemistry (IC) for disialoganglioside GD2 and reverse transcription-PCRs (RT-PCRs) for tyrosine hydroxylase (TH) and pgp9.5 genes. The diagnostic odd ratio (DOR) was used to measure the accuracy of the different techniques. Results: A total of 2,247 evaluations were done on 561 BM, 265 PB, and 69 PBSC samples from 247 patients. IC showed the best accuracy. Whereas TH RT-PCR accuracy was satisfactory, that of pgp9.5 was very low. Positive results obtained by IC in BM and PB samples at diagnosis from stage 1, 2, and 3 patients correlated with unfavourable outcome. No correlation was found between positive results obtained by IC or TH RT-PCR in BM, PB, and PBSC samples from stage 4 patients and their outcome. Conclusions: Because of its elevated diagnostic accuracy, IC may represent a useful adjunct to conventional morphological techniques, especially in view of its potential prognostic role in patients with localized disease. Longitudinal multicenter studies are warranted to definitely establish the clinical usefulness of TH RT-PCR.

Cryptic translocation t(5;11)(q35;p15.5) with involvement of the NSD1 and NUP98 genes without 5q deletion in childhood acute myeloid leukemia

The cryptic translocation t(5;11)(q35;p15.5), which creates a NSD1‐NUP98 fusion gene, has been associated with a deletion of the long arm of chromosome 5, del(5q), in pediatric acute myeloid leukemia (AML) patients with differentiated phenotype. We screened five pediatric cases of AML with apparently normal karyotype by use of fluorescence in situ hybridization analysis and detected one case with early myeloid phenotype and poor clinical outcome, but with the same breakpoints and no del(5q). These findings point to the involvement of t(5;11) as an early event in leukemogenesis. Screening for this translocation in AML patients with apparently normal karyotype at onset is recommended.

Lipoblastoma: a case with t(7;8)(q31;q13).

Lipoblastoma is a rare benign adipose tumor which, in all of the cases so far described, presents an involvement of chromosome 8 in the region 8q11-13. We hereby report the results of the second case of lipoblastoma studied by fluorescence in situ hybridization (FISH), in a 13-month-old boy. An abnormal karyotype 46,XY,t(7;8)(q31;q13) was found in 90% of the metaphases examined, in agreement with the previously reported observations. We suggest the region 8q11-13 may contain a relevant locus for lipoblastoma origin.

Differential diagnosis of lipoma‐like lipoblastoma

Lipoblastomas are rare benign tumors of white fatty tissue that occur primarily in young children. Occasionally, heterogeneity of morphological appearance and histological overlap with other lipogenic tumors are described. In such cases fluorescence in situ hybridization (FISH) analysis of PLAG1, a gene specifically rearranged in lipoblastoma, is necessary to prevent misdiagnosis. We present a case of lipoblastoma arising in an atypical site with histological features characteristic of lipoma. The correct diagnosis was made possible on cytogenetic grounds through the identification of the characteristic PLAG1‐HAS2 fusion gene, thus allowing an appropriate clinical approach. Pediatr Blood Cancer 2009;52:132–134.

Uneventful outcome of unrelated hematopoietic stem cell transplantation in a patient with leukemic transformation of Kostmann syndrome and long-lasting invasive pulmonary mycosis

Abstract: Kostmann syndrome (KS) is an inherited hematological disorder characterized by an absolute neutrophil count (ANC) <0.2 × 109/L and life‐threatening bacterial infections. Granulocyte‐colony stimulating factor (G‐CSF) makes it possible to reach an ANC of 1.0 × 109/L and consequently to reduce significantly the occurrence of severe infections. Absence of response to G‐CSF, G‐CSF receptor mutation, and leukemic transformation are absolute indications to perform hematopoietic stem cell transplantation (HSCT). Pulmonary mycosis does not represent an absolute contraindication to bone marrow transplantation (BMT), although a relapse rate of 30–50% has been reported, despite adequate medical and surgical treatment. Mycotic pneumonia recurrence shows a mortality rate above 80%, especially in the presence of persisting immunosuppression. We report on a KS patient with long‐lasting fungal pneumonia who developed myelodysplasia and subsequent acute myeliod leukemia (AML) conversion resistant to antiblastic therapy. Despite surgical excision and secondary prophylaxis, recurrence of the pulmonary lesion occurred prior to the unrelated HSCT. In spite of these poor prognostic characteristics, outcome was uneventful and the patient is alive and well in continuous complete remission with no signs of fungal infection.

Full cytogenetic characterization of a new neuroblastoma cell line with a complex 17q translocation

Recent studies have shown that structural abnormalities of chromosome 17 resulting in gain of material are the most frequent genetic changes in neuroblastoma. We have established a new neuroblastoma cell line from a patient whose disease had evolved from stage 4s to 4, without evidence of deletion of the short arm of chromosome 1 and MYCN amplification, which are considered the most typical genetic indicators of aggressive disease. The cytogenetic study allowed a full characterization of the chromosome changes, and revealed a complex translocation of chromosome 17 leading to a derivative marker which may be described as follows: der(11)t(11;17)(p15;q12)t(11;17) (q22;q12). This resulted in a gain of part of the long arms of chromosome 17, which was recently associated with poor prognosis.

Is t(10;11)(p11.2;q23) involving MLL and ABI-1 genes associated with congenital acute monocytic leukemia?

Congenital, or perinatal, leukemias are rarely observed, but retrospective molecular studies seem to suggest a more frequent onset in prenatal life. Myelocytic types are common, and chromosome band 11q23 rearrangements at the MLL locus are characteristic genetic markers. The fusion of the MLL gene with one of its partners, ABI-1, has recently been described in two infant leukemia patients with monocytic involvement and good clinical outcome. We report a case of congenital monocytic leukemia with the same gene involvement and good response to chemotherapy. The blast metaphases were probed by fluorescence in situ hybridization, and t(10;11)(p11.2;q23) involving MLL and ABI-1 genes was demonstrated with the same breakpoint in ABI-1. The congenital presentation of this case suggests a possible relationship of this genetic event with in utero leukemogenesis.

Granulocytic sarcoma presenting as an isolated mediastinal mass. A difficult diagnostic problem

ABSTRACT. An unusual case of granulocytic sarcoma presenting in an 8‐year‐old boy as an isolated mediastinal mass, preceding by 7 months the development of acute myeloid leukemia, is reported. The patient was initially treated for lymphoblastic lymphoma, with poor response. We recommend that in such cases, full histocytochemical and immunological characterization of the tumor should be performed.

Meiotic origin of trisomy in neoplasms : evidence in a case of erythroleukaemia

Trisomic cells in neoplasms may represent abnormal clones originated from a tissue-confined mosaicism, and arise therefore by a meiotic error. We report on a 16-month-old child with erythroleukaemia (AML-M6), whose marrow karyotype at onset was 48,XX,del(13)(q12q14),del(14)(q22q32),+21,+21. The parental origin of the supernumerary chromosomes 21 was investigated by comparing 10 polymorphic loci scattered along the whole chromosome on the patients marrow and her parents’ leukocytes. Three loci were informative for the presence of three alleles, two of which were of maternal origin; two further loci showed a maternal allele of higher intensity. Lymphocytes and skin fibroblasts showed a normal karyotype, and molecular analysis on leukocytes at remission, buccal smear and urinary sediment cells consistently showed only one maternal allele, whereas neonatal blood from Guthrie spot showed two maternal alleles as in the marrow. An accurate clinical re-evaluation confirmed a normal phenotype. Our results indicate that tetrasomy 21 arose from a marrow clone with trisomy 21 of meiotic origin. To the best of our knowledge, this is the first evidence that supernumerary chromosomes in neoplastic clones may in fact be present due to a meiotic error. This demonstrates that a tissue-confined constitutional mosaicism for a trisomy may indeed represent the first event in multistep carcinogenesis.

17q21-qter trisomy is an indicator of poor prognosis in acute myelogenous leukemia

A reciprocal translocation (9;11) is often found in acute myeloid leukemia (AML), mostly of the M5a type. We report a case of a child with AML, in whom t(9;11) was observed at diagnosis as the sole structural abnormality, together with trisomies 19 and 21. The diagnosis was AML evolving from a myelodysplastic syndrome (MDS), and the blast morphology was undifferentiated. Chemotherapy failed to induce morphological remission and the patients condition soon worsened. A subclone appeared and expanded during the course of the disease, with an additional unbalanced translocation (1;17) leading to trisomy of the long arm of chromosome 17 (17q). The data available from the literature on acquired anomalies involving 17q and our observation led us to postulate a specific link between the gain of 17q and complete chemoresistance.