Genetic analysis of childhood endodermal sinus tumors by comparative genomic hybridization

Childhood endodermal sinus tumors (CEST) are a distinct category of germ cell tumors that involve the testis and extragonadal sites of young children. Recurrent deletions of 1p and 6q have been reported by classic cytogenetic analysis of a small number of cases. Comparative genomic hybridization, a technique that screens the entire genome for genetic abnormalities, is applied to additionally define the genetic changes present in CESTs. Sixteen frozen CESTs (10 testicular, 6 extragonadal) obtained from Pediatric Oncology Group-affiliated institutions or from the Cooperative Human Tissue Network were analyzed. The most common changes were gain of 20q (10 tumors), 1q (6 tumors), 11q and 22 (4 tumors each), and loss of 6q (8 tumors with common deleted region of 6q24-qter), 16q (4 tumors), and 1p (4 tumors). Localized regions of gain were identified at 8q24 (2 tumors both showing c-myc amplification by fluorescence in situ hybridization). Gain of 12p, characteristic of adolescent germ cell tumor, was present in one testicular tumor. Comparative genomic hybridization was useful in defining genetic differences between adult and childhood tumors, in determining the common regions deleted on chromosome 6, and in identifying other involved loci to be correlated with clinical parameters in future studies.     

Cytogenetic Studies in 45 Pediatric Brain Tumors

Brain tumors are the most frequent childhood tumors. There have been few cytogenetic studies published on these tumors in children compared to the numerous studies on adult brain tumors. We examined chromosomes from 45 primary pediatric brain neoplasms including 14 medulloblastomas, 12 astrocytomas, 4 glioblastomas, 7 ependymomas, 5 craniopharyngiomas, 2 meningiomas, and 1 ganglioglioma. Chromosomal abnormalities were found in 10 medulloblastomas out of the 14 analyzed. The most frequently observed abnormalities were the total or partial loss of one chromosome 17: monosomy 17, i(17q), and a monosomy 22 in 4 cases of desmoplastic medulloblastoma. In glioblastoma, we observed the gain of chromosome 7, chromosome 3, a monosomy 10, and hyperdiploidy. The loss of chromosome X was observed in 2 cases of ependymoma as was a monosomy 22. Our observations show that from the cytogenetic point of view childhood brain tumors differ from adult brain tumors.     

Cmogenetic Analysis In The Examination Of Solid Tumors In Children

Although pediatric solid tumors are cytogenetically less well characterized than childhood leukemias, an understanding of the role of chromosomal changes in the development of these neoplasms is emerging. The major clinical importance of chromosome analysis today is diagnostic. Especially in small cell round cell tumors of childhood, the unique karyotypic patterns that characterize some of the differential diagnostic entities make it possible to determine with a high degree of certainty which type of cancer the child has. Molecular studies have revealed that almost all retinoblastomas show homozygous loss of function of the RBI gene in 13q14. At the cytogenetic level, however, aberrations of 13q are seen in less than 25% of retinoblastomas; instead, the presumably progression-related i(6p) and aberrations leading to gain of 1q predominate, each being present in one-third of the tumors. Twenb percent of cytogenetically aberrant Wilms' tumors show structural rearrangements, often deletions, of 11p13 and 11 p15, where the WT1 and WT2 genes map. Other frequent changes are trisomy 12 and duplication of 1q. The most common (80%) cytogenetic abnormality in neuroblastoma is loss of distal 1p, a chromosome segment thought to harbor at least two tumor-suppressor genes of importance in tumorigenesis. Double minute chromosomes or homogeneously staining regions are present in one-third of all neuroblastomas and are associated with MYCN amplification. Loss of 1p material or MYCN amplification predicts a poor outcome. The most common (30%) chromosomal aberration in primitive neuroectodermal tumors of the central nervous system is i(17q). The formation of this isochromosome may help inactivate a tumor-suppressor gene located distal to the TP53 locus on 17p. No specific chromosome abnormality has been detected in gliomas, but monosomy 22 and rearrangements leading to loss of 1p and gain of 1q are recurrent. Few hepatoblastomas with chromosomal changes have been reported, but several potential primary aberrations have been described, including + 2, + 20, and duplication 8q. In Ewing's sarcoma, t(l1;22)(q24;q12) is the primary aberration, with trisomy 8 and gain of 1q being frequent secondary changes. Fibrosarcomas in children often carry only numeric aberrations, especially trisomy for chromosomes 11, 20, 17, and 8. Most osteosarcomas are cytogenetically complex, and no specific abnormality has been detected; the single most common change is loss of chromosome 13, which is observed in half the tumors. In contrast, the low-malignancy parosteal osteosarcomas often display supernumerary ring chromosomes as the sole karyotypic deviation. The cytogenetic profiles of rhabdomyosarcomas differ among the various morphologic subtypes. The alveolar type is characterized by t(2;13)(q35-37;q14), whereas the embryonal form typically has only numeric changes, in. particular +2, + 8, + 11, and +20.     

Renal Metanephric Adenoma With Previously Unreported Cytogenetic Abnormalities: Case Report and Review of the Literature

We report a case of a renal metanephric adenoma in a 10-year-old boy, in which cytogenetic analysis showed a balanced translocation, t(9;15)(p24;q24) and a balanced paracentric inversion of chromosome 12, inv(12)(q13q15). Immunohistochemically, the tumor showed diffuse reactivity for cytokeratin AE1/AE3, CAM5.2, CD57, and WT1; patchy reactivity for CD56; and focal reactivity for cytokeratin 7, epithelial membrane antigen, and CD10. Tumor cells were entirely nonreactive for α-methyl acyl coenzyme A racemase. Published cytogenetic data for metanephric adenomas are limited, and this is the first report of these cytogenetic abnormalities. The involvement of the chromosome region 9p24 is particularly interesting because of the recent identification of a tumor suppressor gene, KANK (kidney ankyrin repeat-containing protein), at this locus.     

Cytogenetic findings in Wilms' tumor

We report the cytogenetic analysis of 20 Wilms'tumors. In 10 cases chromosomal abnormalities were found: Besides the expected aberrations involving 11p13 we found chromosome 11 breakpoints at 11p15, 11q13 or q23. Chromosome 1 was frequently involved in rearrangements, with partial trisomy 1q as the typical abnormality. Additional chromosomes 8, 12, 13, 17 and 20 were the most frequent numerical changes. This study is part of efforts to find cytogenetic and molecular markers and constellations contributing important information beyond histology and DNA-measurements.     

Variation in prevalence of chromosome 22q11 deletion in subtypes of conotruncal defect in 254 children

Aim: To determine the frequency of chromosomal aberrations particularly 22q11 deletion in Indian children ≤2 years with different types of conotruncal malformations and their association with abnormal aortic arch. Additionally, extracardiac features were also studied. Methods: Conventional cytogenetic and fluorescence in situ hybridization analyses were performed in 254 patients with conotruncal defects. Multivariable logistic regression analysis was performed to ascertain extracardiac features helpful in identifying high‐risk patients with deletion. Results: Chromosomal abnormalities were identified in 52 (21%) children, of whom 49 (94%) showed 22q11 deletion and 3 (6%) had abnormalities of chromosome 6, 2 and X. None of the 11/254 children with tetralogy of Fallot with absent pulmonary valve showed deletion. The association of 22q11 deletion with right sidedness of the aortic arch varied with the type of conotruncal defect. The eight extracardiac features in combination showed 93.5% agreement with the presence of deletion. Conclusion: The extracardiac features along with specific type of conotruncal defect and associated cardiovascular anomaly should alert the clinician for 22q11 deletion testing. However, if deletion analysis is not possible, specific extracardiac features (six dysmorphic facial features, thin long fingers and hypocalcemia) can help to identify an increased risk of 22q11 deletion in patients with conotruncal defect.     

Primary Subcutaneous Primitive Neuroectodermal Tumor with Aggressive Behavior and an Unusual Karyotype: Case Report

Primitive neuroectodermal tumor/Ewing sarcoma (PNET/ES) rarely occurs in the skin and subcutaneous tissues. We present a case of a 16-year-old girl with primary cutaneous and subcutaneous PNET/ES of the abdominal wall. Despite wide local excision and chemotherapy, she rapidly developed cranial bone and brain metastases, followed by lung and skeletal metastases, and died shortly thereafter. The recurrent tumor exhibited light microscopic features of a small, round, blue cell tumor with intracytoplasmic glycogen. Immunohistochemical analysis showed positivity for CD99, CD56, S100, and glial fibrillary acid protein, and ultrastructural features included cytoplasmic glycogen and focal complex interdigitating synaptic junction-like cytoplasmic folds. Cytogenetic analysis of the relapsed tumor showed a complex karyotype: 47,XX,i(1)(q10), der(4)t(4;19) (q33q35;q13.1), + 8,t(15;17)(q24;p11.2p12),der(19)t (19;20)(q13.1;p11.2),der(22)t(20;22)(q13;q13). Cytogenetic, interphase fluorescence in situ hybridization, and molecular genetic analyses failed to show t(11:22) (q24;q12) or abnormalities of chromosome region 22q12. The clinical behavior and atypical and complex cytogenetic abnormalities exhibited by the tumor in this patient are unusual and represent the most aggressive end of the clinical spectrum of cutaneous and subcutaneous PNET/ES.     

伴骨髓转移的神经母细胞瘤患儿初诊时骨髓染色体核型的临床意义

目的总结伴骨髓转移的神经母细胞瘤(NB)患儿初诊时骨髓染色体核型分析结果,探讨其临床意义。方法采用G显带的方法,对2015年1月至2017年12月北京儿童医院血液肿瘤中心收治的伴骨髓转移的NB患儿进行染色体核型分析,总结临床特点、分析预后,随访至2018年12月31日。结果1.共120例患儿,男74例,女46例,≥18个月者98例(81.7%)。染色体正常组60例,其中56例(93.3%)国际神经母细胞瘤分期系统(INSS)-Ⅳ期,余4例为INSS-Ⅳs期;低危(LR)2例,中危(MR)9例,高危(HR)49例(81.7%);7例患儿MYCN基因扩增。染色体异常组60例患儿均为INSS-Ⅳ期,MR 1例,余59例(98.3%)均为HR,14例MYCN基因扩增。2.染色体异常患儿60例中单纯数目异常和结构异常者分别为4例、14例,42例患儿同时合并染色体数目及结构异常。数目异常方面,21号、10号、11号染色体缺失最为常见;结构异常方面涉及11q、1p、3p区段的异常发生率高。3.染色体正常组患儿随访时间为4~44个月,17例出现肿瘤进展或复发;染色体异常组患儿随访时间2~42个月,其中31例出现肿瘤进展或复发。所有患儿3年累积总生存率和累积无事件生存率分别为60.0%、48.4%;染色体正常组患儿3年累积生存率为74.2%,3年累积无事件生存率为65.7%;染色体异常组患儿3年累积生存率为47.5%,3年累积无事件生存率为24.9%;出现进展或复发患儿染色体数目异常以10号染色体缺失常见,结构异常以11q、1p、2p区域较多。结论NB患儿肿瘤细胞染色体异常率高,但重复率低,个体间差异明显。10号染色体缺失、11q、1p、2p区域结构异常可能为提示NB预后不良因素;通过骨髓标本进行肿瘤染色体核型分析可行,可为更精准的危险度分层和治疗提供依据。     

儿童骨髓增生异常综合征细胞遗传学研究及临床意义

目的探讨儿童骨髓增生异常综合征(MDS)遗传学改变及临床意义。方法采用直接法及24h培养法用R或G带显色技术对28例儿童MDS进行遗传学分析。结果28例MDS中13例检出异常核型,FAB亚型中的分布:RA33.3%(3/9例);RAS0%(0/1例);RAEB42.9%(3/7例);RAEB蛳t63.6%(7/11例)染色体改变以-5/5q、 7/-7、 8、 21等数量变化为主。结论MDS的遗传学改变有多样性,在诊断及预后的判断中有重要意义。     

GIANT CELL TUMOR OF TENDON SHEATH ARISING IN THE TOE

Giant cell tumor of the tendon sheath (nodular synovitis) is a benign soft tissue tumor, usually affecting older women, that most often occurs in the interphalangeal joints of the fingers. Occurrence is rare in children. We present a 12-year-old boy and a 6-year-old girl with giant cell tumors of tendon sheaths occurring in the toes. The tumor from the 12-year-old demonstrated the cytogenetic finding of t(1;2)(p13;q37), which previously has been associated with giant cell tumor of tendon sheath in adults. Giant cell tumors of the tendon sheath occurring in children have similar histological and cytogenetic features as adults, however, there may be a predilection for lower extremity involvement.     

Genetic analysis of childhood germ cell tumors with comparative genomic hybridization

BACKGROUND: Germ Cell Tumors (GCTs) in children and adolescents constitute a clinically and histologically heterogeneous group of tumors. Compared to GCTs in adults, the numbers of GCTs in children analyzed with cytogenetic and molecular genetic techniques is limited. However, the data available to date reveal a pattern of cytogenetic aberrations different from that in adults. Comparative genomic hybridization (CGH) is a valuable technique for the genetic profiling of tumors that allows screening for chromosomal imbalances consistent with amplification of oncogenes and loss of putative tumor suppressor genes. As CGH does not require tissue culture, it also allows analysing archival tissue samples. PATIENTS: This study focuses exclusively on GCTs in children younger than ten years of age and summarizes the genetic data of 51 tumors. Eighteen teratomas and 33 malignant GCTs were included. Primary sites were the testis (n=10), coccyx (n=13), mediastinum (n=20), ovary (n=5), CNS (n=2), and the face (n=1). METHODS: The experimental procedure includes differential enzymatic fluorescence labeling of tumor and control DNA followed by comparative hybridization to normal male chromosomes, karyotyping and computerized analysis of the fluorescence profiles. RESULTS: With the exception of one testicular and two ovarian tumors, malignant GCTs in children do not show chromosomal gain of 12p, which is characteristic of GCTs in adult patients. Irrespective of the primary site, childhood GCTs show chromosomal imbalances of chromosome 1 (loss of distal 1p, gain of 1q), deletion of 4q and 6q as well as gain of 20q at a high frequency. CONCLUSIONS: These studies will help guiding further investigations elucidating the role of putative tumor suppressor genes at e.g. 1p36 and 6q. In addition, further studies incorporated in prospective therapeutic protocols are necessary to evaluate the prognostic relevance of specific genetic aberrations.     

Cytogenetic Findings in Pediatric T-Lymphoblastic Lymphomas: One Institution’s Experience and a Review of the Literature

Cytogenetic analyses of lymphomas commonly reveal nonrandom chromosomal abnormalities, but there are relatively few reports in childhood lymphoblastic lymphoma (LL). We retrospectively reviewed G-banded karyotypic analyses performed at Arkansas Children’s Hospital between 1990 and 2004. Six children (2 to 20 years old) had LL that presented as mediastinal or cervical masses and had a T-cell immunophenotype and clonal abnormalities. The cytogenetic findings in these 6 patients were as follows: 46,XX,?7,inv(9)(p11q12),der (12)t(7;12)(q11.2;p13),t(16;18)(p13.1;q21),+22 in patient 1; 47,XX,+9,del(9)(q11q22)x2 in patient 2; 72?119, XY,+X,+1,+1, inv(2) (p11q13),?3,+5,+6,+7,+10,?12,?16, ?21,?21,?22,+mar in patient 3; 48,XY,+5,+20,t(7;9) (q32;q34) in patient 4; 47～48,XX,der(10)t(10;14)(q23; q11.2),+12, del(12)(p12)x2, ?14,del(16)(q22q22),+?add (19)(p13.3) in patient 5; and 48～49,XY,+7,+8,t(11;19) (q23;p?13.3),+der(19)t(11;19)[cp20] in patient 6. Eleven chromosome breakpoints in 6 of our patients (7q11, 12p13, 16p13, 18q21, 9q11, 2p11, 2q13, 7q32, and 7q23) have been reported in other patients with acute lymphoblastic leukemia or LL and involved regions containing TEL, ABL, E2A, MLL, and T-cell receptor-α genes. A review of the cytogenetic findings of these and other cases of LL reveals that clonal aberrations are common and most frequently involve T-cell receptor gene regions. The aberrations show some features similar to those of acute lymphoblastic leukemia and are not unique to LL, thus furnishing additional evidence of the equivalence of these two diseases. The cytogenetic features of LL may be helpful in the diagnosis of pediatric lymphomas and undifferentiated neoplasms.     

Germ cell tumor showing partial trisomy 1 in a gonadectomized intersex child with monosomy X and double Y mosaicism

High incidence of germ cell tumors arising from dysgenetic gonads in patients with sexual chromosome abnormalities has been described, especially in patients with a Y chromosome bearing cell line. Here we report a 14-year-old patient with ambiguous genitalia. Constitutional karyotype showed 45,X/46,X,derY [?t(Yp;Yq)] mosaicism. The patient developed an abdominally located mixed malignant germ cell tumor 5 years after the removal of the dysgenetic gonads. Tumor karyotype showed partial trisomy 1q, a derivative 8q, and a hyperdiploidy with +X, +7, +12, +15, +19, +21, and an unidentified marker.     

5q- syndrome in a child with slowly progressive pancytopenia: a case report and review of the literature

5q- syndrome is a rare myelodysplastic process occurring predominately in middle aged to elderly women. In children, myelodysplasia of all types is rare and 5q- syndrome is exceptionally rare. Only 6 cases of 5q- associated myelodysplasia have been reported in children and all 6 cases had blast counts >5% and/or additional cytogenetic abnormalities. We report a case of 5q- syndrome in a girl who presented with macrocytosis and intermittent pancytopenia at age 5. Cytogenetic studies at age 8 revealed a large interstitial deletion of chromosome 5q without other cytogenetic abnormalities. The patient was clinically stable until age 11, when she became transfusion dependent and severely neutropenic. Subsequently, she underwent a successful unrelated cord blood transplant. To our knowledge, this is the first reported pediatric case meeting the strict criteria for 5q- syndrome.     

NEOPLASTIC DISEASE AND DELETION 22q11.2: A MULTICENTRIC STUDY AND REPORT OF TWO CASES

Deletion 22q11.2 is a chromosomal abnormality detected in young patients with clinical manifestations of the DiGeorge/velocardiofacial syndrome. Conotruncal heart defects are also associated with del22q11.2. An association of these cardiac malformations with neoplasias has been observed. Our series includes two cases of malignancies, a hepatoblastoma and a renal-cell carcinoma, arising in children with complex cardiac malformations. The aim of the study was to determine if the deletion at 22q11.2 was present and could be responsible for both pathological processes. Del22q11.2 was identified in both cases. Comparative genomic hybridization revealed terminal gains on chromosomes 1q and Xq and terminal loss on 1p in the hepatoblastoma, and gains in 1p, 12q, 16p, 20q, 22q, and whole chromosome 19 and loss of Xq in the renal-cell carcinoma. Our results confirm a common genetic basis for cardiac malformations, and del22q11.2 presents a risk factor for the development of pediatric tumours.     

Monosomy 5 (-5), deletion of the long arm of chromosome 6 (6q) and acquisition of a chromosome 21 (+21) in a boy with acute leukemia at high-risk

The chromosomal abnormality 6q-, associated with acute lymphatic leukemia, is often found both in T cell form and in non T non B cell forms. The absence of chromosome -5, frequently associated with acute non-lymphatic leukemia of the adult, has been rarely found in the acute non-lymphatic leukemia of the child. Trisomy of chromosome 21 is the most associated with acute non-lymphatic leukemia of the adult, has been rarely found in the acute non-lymphatic leukemia of the child. Trisomy of chromosome 21 is the most frequent alteration found in children and adult with acute lymphatic leukemia. In a child (aged 7) affected by acute lymphatic leukemia the karyotype analysis showed simultaneously the presence of the 3 above mentioned abnormalities. It will be important to evaluate later on how the association of monosomy 5 with the deletion of chromosome's 6 long arm and with an acquired chromosome 21, the last two being indexes of a favourable prognosis, can influence the clinical course of the disease.     

Deletion of 11q23 is a frequent event in the evolution of MYCN single-copy high-risk neuroblastomas

BACKGROUND: Deletions of the long arm of chromosome 11 are frequently identified in human neuroblastomas. PROCEDURE: We screened 394 primary neuroblastomas and 52 tumor-derived cell lines with a panel of 11q and 11p polymorphic markers to determine the frequency of chromosome 11 allelic deletion, and to differentiate partial deletions of chromosome 11q (unb[11q] LOH) from whole chromosome loss. RESULTS: Allelic deletion occurred most frequently at cytogenetic band 11q23 and was detected in 161 primary neuroblastomas (41%) and 18 cell lines (35%). Eighty-seven tumors (22%) had unb[11q] LOH with a heterogeneous distribution of deletion breakpoints. Unb[11q] LOH was highly correlated with age > 1 year at diagnosis (P = 0.008), stage 4 disease (P = 0.001), unfavorable Shimada histopathology (P < 0.001), and assignment to a high-risk therapeutic protocol (P < 0.001), and was inversely correlated with MYCN amplification (P = 0.018). Patients whose tumors showed unb[11q] LOH were less likely to survive (P < 0.001), but there was only a trend towards an independent prognostic influence in multivariate analyses. CONCLUSIONS: Thus, structural rearrangements resulting in unb[11q] LOH commonly occur during the malignant evolution of high-risk neuroblastomas with single-copy MYCN.     

Ring chromosome 4: Wolf syndrome and unspecific developmental anomalies

A new case of ring chromosome 4 in a 18-month-old girl is described. The patient presented extreme growth failure, psychomotor retardation, and some features of 4p deletion or Wolf syndrome. No significant loss of genetic material could be seen by G-banding technique (breakpoints p16q35). The ring was found to be unstable both in lymphocyte and fibroblast culture and a substantial proportion of aneuploid cells containing derivatives of the ring could be observed. An increased cell death-rate could be detected by cell viability determination with trypan blue in the first subculture of skin fibroblasts. It is suggested that this finding is a consequence of behavioural instability of the ring at mitosis existing probably in vivo as well. The clinical and cytogenetic findings in this patient were compared with those in the other 16 cases with ring 4 published so far. It is suggested that the phenotype in patients with this chromosomal anomaly is a mixture of phenotypic abnormalities generated by both the chromosomal deletion prior to ring formation (features of Wolf syndrome) and the behavioural instability of the ring at mitosis (unspecific developmental anomalies).     

Fluorescent in situ hybridization (FISH) reveals frequent and recurrent numerical and structural abnormalities in hepatoblastoma with no informative karyotype

BACKGROUND: Hepatoblastoma (HB) is the most frequent malignant liver tumor in children. The few cytogenetic studies available indicate that HB is associated with recurring trisomies of chromosomes 2, 8, and 20; recurrent t(1;4) (q12;q34) has been reported in few cases. The abnormalities of chromosome 1q are relatively frequent and usually lead to overexpression of 1q material. A cluster of breakpoints is located at the level of bands 1q12 and 1q21. More work is needed to clarify their real incidence and prognostic significance. Cytogenetic analysis is limited by the requirement of suitable cells in metaphase. A different method that increases analysis sensitivity is fluorescent in situ hybridization (FISH). PROCEDURE: We studied 10 cases of HB with no informative karyotype (normal karyotype or no metaphases). FISH was performed by the standard method, using cytospins and imprints obtained from frozen or cytogenetic samples of direct cultures. Alpha-satellite probes for centromeric DNA were used for chromosomes 2, 8, and 20 analysis; rearrangement of region 1q12-21 was detected with BAC (bacterial artificial chromosome) probe bA79E5. RESULTS: We detected at least one trisomic clone in 5/10 of these cases. Trisomy 20 was the most frequently detected abnormality, followed by trisomy of the chromosomes 2 and 8. Analysis of 1q12 band revealed that the rearrangement of 1q usually is in pericentromeric heterochromatin, it was present in 5/10 of studied cases. CONCLUSION: FISH analysis is recommended in all cases of HB with no informative karyotype to gain more information regarding the frequent trisomies encountered and their significance.