Karyotypic abnormalities associated with Epstein-Barr virus status in classical Hodgkin lymphoma.

Classical Hodgkin lymphoma (CHL) is morphologically characterized by scattered malignant Hodgkin/Reed-Sternberg (HRS) cells that are far outnumbered by surrounding reactive hematolymphoid cells. Approximately half of all cases of CHL are associated with infection by Epstein-Barr virus (EBV), an oncogenic herpesvirus that expresses a number of proteins thought to contribute to transformation. While a small number of published studies have attempted to identify recurrent cytogenetic abnormalities in CHL, no large case series have explored karyotypic differences between EBV-positive and EBV-negative tumors. Here, we report a two-institution retrospective investigation of cytogenetic features characterizing CHL. In our cohort, cases of EBV-negative CHL were characterized by more complex routine karyotypes than their EBV-positive counterparts (24.6 versus 15.6 independent aberrations per case, P = 0.009). The increased complexity of EBV-negative cases was driven by a number of features suggestive of genomic instability, including a larger number of independent chromosomal breakpoints (P = 0.03) and apparently aneuploid autosomes (P = 0.008). Compelling but nonsignificant trends also suggest a larger modal number and increased marker chromosomes in EBV-negative cases (P = 0.13 and 0.06, respectively). While some of these differences are related to histologic subtype, others appear independent of histology. Finally, a significant subset of EBV-positive tumors has a surprisingly simple karyotype relative to what is normally seen in CHL, an observation suggesting considerable biological and genetic diversity in this disease.

Section E6.5-6.8 of the ACMG technical standards and guidelines: chromosome studies of lymph node and solid tumor-acquired chromosomal abnormalities.

DISCLAIMER: These ACMG standards and guidelines are developed primarily as an educational resource for clinical laboratory geneticists to help them provide quality clinical laboratory genetic services. Adherence to these standards and guidelines is voluntary and does not necessarily ensure a successful medical outcome. These standards and guidelines should not be considered inclusive of all proper procedures and tests or exclusive of other procedures and tests that are reasonably directed to obtaining the same results. In determining the propriety of any specific procedure or test, the clinical laboratory geneticist should apply his or her own professional judgment to the specific circumstances presented by the individual patient or specimen. Clinical laboratory geneticists are encouraged to document in the patient's record the rationale for the use of a particular procedure or test, whether or not it is in conformance with these standards and guidelines. They also are advised to take notice of the date any particular guideline was adopted, and to consider other relevant medical and scientific information that becomes available after that date. It also would be prudent to consider whether intellectual property interests may restrict the performance of certain tests and other procedures.Cytogenetic analysis of tumor tissue is performed to detect and characterize chromosomal aberrations to aid histopathological and clinical diagnosis and patient management. At the time of diagnosis, known recurrent clonal aberrations may facilitate histopathological diagnosis and subtyping of the tumor. This information may contribute to clinical therapeutic decisions. However, even when tumors have a known recurrent clonal aberration, each tumor is genetically unique and probably heterogeneous. It is important to discover as much about the genetics of a tumor at diagnosis as is possible with the methods available for study of the tumor material. The information gathered at initial study will inform follow-up studies, whether for residual disease detection, determination of relapse and clonal evolution, or identifying a new disease clone.This updated Section E6.5-6.8 has been incorporated into and supersedes the previous Sections E6.4 and E6.5 in Section E: Clinical Cytogenetics of the 2009 Edition (Revised 01/2010), American College of Medical Genetics and Genomics Standards and Guidelines for Clinical Genetics Laboratories. This section deals specifically with the standards and guidelines applicable to lymph node and solid tumor chromosome analysis.Genet Med 18 6, 643-648.

Breast Cancer and Non-Hodgkin Lymphoma in a Young Male with Cowden Syndrome.

Male breast cancer (MBC) is unusual, especially in young adults. Most cases of MBC as a secondary malignancy relate to the previous treatment with ionizing radiation. MBC can be associated with mutations in hereditary cancer predisposition syndrome genes (i.e., BRCA2); however, no such association has been reported in patients with Cowden syndrome (involving the phosphatase and tensin homolog [PTEN] gene). We describe a patient with Cowden syndrome who was initially diagnosed with B-cell lymphoblastic lymphoma at the age of 7 years, then MBC at the age of 31 years, and never received radiation therapy.

Aplastic Anemia in Two Patients with Sex Chromosome Aneuploidies.

Sex chromosome aneuploidies range in incidence from rather common to exceedingly rare and have a variable phenotype. We report 2 patients with sex chromosome aneuploidies who developed severe aplastic anemia requiring treatment. The first patient had tetrasomy X (48,XXXX) and presented at 9 years of age, and the second patient had trisomy X (47,XXX) and presented at 5 years of age. Although aplastic anemia has been associated with other chromosomal abnormalities, sex chromosome abnormalities have not been traditionally considered a risk factor for this condition. A review of the literature reveals that at least one other patient with a sex chromosome aneuploidy (45,X) has suffered from aplastic anemia and that other autosomal chromosomal anomalies have been described. Despite the uncommon nature of each condition, it is possible that the apparent association is coincidental. A better understanding of the genetic causes of aplastic anemia remains important.

Papillary tumor of the pineal region with synchronous suprasellar focus and novel cytogenetic features.

Papillary tumor of the pineal region (PTPR) is an uncommon neoplasm with variable biologic behavior. Cytogenetic and molecular diagnostic studies are rare, yielding no definitive genetic signature. We report a case of PTPR with a multicentric presentation and unusual cytogenetic features. A 25-year-old man presented with headache, disconjugate gaze, and confusion. Mass lesions in the pineal and suprasellar regions, with identical imaging characteristics, were identified. The former extended partially into the fourth ventricle. It showed typical PTPR histology and losses of chromosomes 3, 7, 10, 14, 18, and Y with gains of chromosomes 3, 8, and 9. Seventeen months postsurgery, the patient is stable without disease progression after radiation therapy. Synchronous mass lesions at presentation and losses of chromosomes 3, 7, 14, 18, and Y are unusual features, adding to the available data and underscoring the biologic and genetic variability associated with these neoplasms.

Isolated MYC cytogenetic abnormalities in diffuse large B-cell lymphoma do not predict an adverse clinical outcome.

In this study, we investigated the significance of MYC, BCL2 and BCL6 gene abnormalities in a cohort of 205 diffuse large B-cell lymphoma (DLBCL) patients studied by conventional and/or fluorescence in situ hybridization cytogenetic analysis. Combining these methods, 172 cases (84%) were classified as MYC-, 17 (8%) were MYC+/BCL2-/BCL6-, and 16 (8%) were double/triple-hit lymphomas (i.e. MYC+/BCL2+, MYC+/BCL6+, or MYC+/BCL2+/BCL6+). We found a significant difference in event-free survival (EFS) among the three groups (p = 0.02), with the double/triple-hit group having the worst EFS. Patients who were MYC+, but BCL2- and BCL6-, had the best EFS. We conclude that patients with MYC+ DLBCL, but without BCL2 or BCL6 abnormalities, do not have a worse outcome when compared to those who are MYC-. However, patients with double/triple-hit DLBCL have a very poor outcome and should be treated with aggressive or novel therapies.

Assessing the utility of confirmatory studies following identification of large-scale genomic imbalances by microarray.

PURPOSE: The identification of clinically relevant genomic dosage anomalies assists in accurate diagnosis, prognosis, and medical management of affected individuals. Technological advancements within the field, such as the advent of microarray, have markedly increased the resolution of detection; however, clinical laboratories have maintained conventional techniques for confirmation of genomic imbalances identified by microarray to ensure diagnostic accuracy. In recent years the utility of this confirmatory testing of large-scale aberrations has been questioned but has not been scientifically addressed. METHODS: We retrospectively reviewed 519 laboratory cases with genomic imbalances meeting reportable criteria by microarray and subsequently confirmed with a second technology, primarily fluorescence in situ hybridization. RESULTS: All genomic imbalances meeting reportable criteria detected by microarray were confirmed with a second technology. Microarray analysis generated no false-positive results. CONCLUSION: Confirmatory testing of large-scale genomic imbalances (deletion of ≥150 kb, duplication of ≥500 kb) solely for the purpose of microarray verification may be unwarranted. In some cases, however, adjunct testing is necessary to overcome limitations inherent to microarray. A recommended clinical strategy for adjunct testing following identified genomic imbalances using microarray is detailed.

Allogeneic stem cell transplantation for Philadelphia chromosome-positive acute myeloid leukemia.

Philadelphia chromosome-positive acute myeloid leukemia (Ph(+)-AML) has a poor response to anthracycline- and cytarabine-containing regimens, high relapse rate, and dismal prognosis. Although therapy with imatinib and allogeneic stem cell transplantation (allo-SCT) is promising, relatively short follow-up limits understanding of long-term results of these therapies. This report describes the outcomes of 3 cases of Ph(+)-AML diagnosed and transplanted at the University of Nebraska Medical Center between 2004 and 2011. These patients, young and without major comorbidities, received induction therapy with 7 days of cytarabine and 3 days of idarubicin along with imatinib and consolidation therapy with high-dose cytarabine (with or without imatinib). All patients underwent 10/10 HLA-matched peripheral blood allo-SCT (sibling donor for first and third patients and unrelated donor for the second patient; all had acute graft-versus-host disease (GVHD), and the first and third patients had chronic GVHD. All patients are currently alive and experiencing complete remission at 116, 113, and 28 months after diagnosis, respectively. This report shows that the use of allo-SCT with resultant graft-versus-leukemia effect and the addition of imatinib can result in long-term remission and possible cure in some patients with Ph(+)-AML.

Duplication of 20qter and deletion of 20pter due to paternal pericentric inversion: patient report and review of 20qter duplications.

Duplications of the terminal long arm of chromosome 20 are rare chromosomal anomalies. We report a male infant found on array comparative genomic hybridization analysis to have a 19.5 Mb duplication of chromosome 20q13.12-13.33, as well as an 886 kb deletion of 20p13 at 18,580-904,299 bp. This anomaly occurred as the recombinant product of a paternal pericentric inversion. There have been 23 reported clinical cases involving 20qter duplications; however, to our knowledge this is only the second reported patient with a paternal pericentric inversion resulting in 46,XY,rec(20)dup(20q). This patient shares many characteristics with previously described patients with 20qter duplications, including microphthalmia, anteverted nares, long ears, cleft palate, small chin, dimpled chin, cardiac malformations, and normal intrauterine growth. While there is variable morbidity in patients with terminal duplications of 20q, a review of previously reported patients and comparison to our patient's findings shows significant phenotypic similarity.

Occurrence of nephroblastomatosis with dup(18)(q11.2-q23) implicates trisomy 18 tumor screening protocol in select patients with 18q duplication.

Duplications of the long arm of chromosome 18 have been previously reported in patients with phenotypic findings similar to full trisomy 18. Trisomy 18 increases the risk for Wilms tumor and it is currently recommended that these patients undergo abdominal ultrasonography screening every 6 months. We report on nephroblastomatosis in a 27-month-old male with a 55 Mb duplication of chromosome 18q11.2-q23 (chr18:22693370-77982126, hg 19) and propose that the trisomy 18 tumor screening protocol could also benefit patients with large 18q duplications.

Cytosine arabinoside and mitoxantrone followed by second allogeneic transplant for the treatment of children with refractory juvenile myelomonocytic leukemia.

Hematopoietic stem cell transplantation (HSCT) remains the only curative option for most patients with juvenile myelomonocytic leukemia (JMML). However, persistent disease and relapse rates after transplant range from 26% to 58%. We report the successful use of second HSCT after preparation with mitoxantrone and cytosine arabinoside (Ara-C) for patients with refractory or recurrent disease. Between 1993 and 2006, 5 children who underwent HSCT at our institution as initial therapy for JMML had persistent disease or relapsed. Pre-HSCT conditioning varied and donors were either HLA-matched siblings (n=2) or matched unrelated donors (n=3). After initial HSCT, they subsequently received high-dose Ara-C (3 g/m IV) every 12 hours on days -8 through -3 and mitoxantrone (10 mg/m/d IV) on days -8, -7, -6 followed by second HSCT from their original donors. All 5 patients are alive at 88, 179, 199, 234, and 246 months with no evidence of JMML, no significant toxicity, and 100% donor chimera as determined by PCR short-tandem repeat analysis. Our experience supports second transplant utilizing high-dose Ara-C and mitoxantrone in children with JMML who do not respond or relapse after first transplant.

Differences in the cytogenetic alteration profiles of diffuse large B-cell lymphoma among Chinese and American patients.

To study the similarities and differences of cytogenetic alterations in diffuse large B-cell lymphoma (DLBCL) between Asian and Caucasian patients, we compared the cytogenetic profiles of Chinese and American DLBCL cases by analyzing conventional karyotypes and select fluorescence in situ hybridization (FISH) findings. We used interphase FISH analyses to determine the incidence of the t(14;18) and BCL6 and MYC rearrangements. Immunohistochemical analysis was used to categorize the lymphomas into the germinal center B-cell-like (GCB) or non-GCB-DLBCL subtypes, according to the Hans algorithm. Our data suggested that Chinese patients had cytogenetic profiles for GCB-DLBCL that differed from those of their American counterparts; specifically, the Chinese GCB patients exhibited greater frequencies of BCL6 rearrangements and gains of 1q and 11q but lower incidence of the t(14;18). Non-GCB-DLBCL in both the Chinese and American patients was characterized by recurrent gains of 3/3q and 18/18q. The incidences of both BCL6 rearrangement and t(14;18) were similar in Chinese and American non-GCB-DLBCL cases.

Report of a patient with developmental delay, hearing loss, growth retardation, and cleft lip and palate and a deletion of 7q34-36.1: review of distal 7q deletions.

The use of aCGH has improved our ability to find subtle cytogenetic abnormalities as well as to find more precise information in patients with previously known abnormalities. In addition, it has allowed more specific genotype-phenotype correlation. In this report we describe a patient with a chromosomal deletion initially diagnosed with conventional cytogenetic analysis which was redemonstrated and more specifically described upon aCGH analysis. Our patient is a 12-year-old female born to a 26-year-old G1P0 mother. She was noted as a neonate to have a bilateral cleft lip and cleft palate, abnormal external ears, dysmorphic facies, and moderate to severe hearing loss. She has subsequently shown developmental delay, hyperreflexia, seizures, hyperactivity, and absence of speech. Chromosomal analysis showed deletion of 7q34q36.1. FISH studies confirmed the deletion was interstitial. Parental chromosomes were performed and did not show any cytogenetic abnormalities. aCGH was recently performed for the patient to further characterize the breakpoints of the deletion and confirmed the deletion was interstitial and of 13.2 Mb in size. Both proximal and terminal 7q deletion show a different phenotype than that of our patient. A number of patients with similar deletions have been found and while significant variability is observed, a number of findings appear to be common to deletions in this region. Therefore, we feel that distal interstitial deletions of chromosome 7q represent a recognizable phenotype and could be considered a separate deletion syndrome.

Cytogenetic abnormalities in follicular dendritic cell sarcoma: report of two cases and literature review.

BACKGROUND: The identification of chromosomal abnormalities in many hematopoietic and mesenchymal neoplasms has contributed significantly to classification systems. Follicular dendritic cell (FDC) sarcoma is an intermediate-grade malignancy with morphological and immunophenotypic features of follicular dendritic cells. Available data on genetic changes in this neoplasm are limited, with only isolated case reports of cytogenetic abnormalities. CASE REPORT: We reviewed histological, immunophenotypic and cytogenetic findings in two cases of FDC sarcoma. The two cases of FDC sarcoma, were observed in female patients, one was nodal and one extranodal and they exhibited relatively complex karyotypes, characterized by structural abnormalities and loss of multiple chromosomes. One patient had several disease recurrences. At the last follow-up both patients were alive with no residual disease. CONCLUSION: The cytogenetic findings in these two cases, coupled with the few previously described abnormal karyotypes, suggest that FDC sarcoma is cytogenetically diverse.

Early onset, EBV(-) PTLD in pediatric liver-small bowel transplantation recipients: a spectrum of plasma cell neoplasms with favorable prognosis.

EBV(-) posttransplantation lymphoproliferative disorders (PTLDs) are rare compared with EBV(+) PTLDs, occur later after transplantation, and have a poor response to treatment. Few studies have reported EBV(-) PTLD in pediatric solid-organ transplantation recipients. We describe 5 cases of EBV(-) PTLD in recipients of combined liver and small bowel allografts ranging in age from 16 months to 7 years. EBV(-) PTLD developed 9-22 months (median, 15) after transplantation. Morphologically, the lesions ranged from atypical plasma cell hyperplasia (a term not currently included in the World Health Organization classification) to plasmacytoma like. In all cases, in situ hybridization for EBV was negative, and molecular studies demonstrated clonal IgH gene rearrangements. Protein electrophoresis showed multiple clonal paraproteins in 4 of 5 cases. In 2 cases with a donor-recipient sex mismatch, FISH cytogenetics demonstrated that the plasma cells were of mixed donor/recipient origin. One patient died before therapy. Four patients were treated with high-dose dexamethasone, and 1 patient subsequently required thalidomide. All 4 remain in remission 75-128 months (median, 86) after diagnosis. In contrast to reports of EBV(-) PTLD in adults, these plasma cell lesions occurred early after transplantation and resolved completely after minimal treatment.

Immunohistochemical and molecular cytogenetic evaluation of potential targets for tyrosine kinase inhibitors in Langerhans cell histiocytosis.

Langerhans cell histiocytosis is a rare disorder of Langerhans cells, a component of the dendritic cell system, with an unknown pathogenesis. Conventional therapy for patients with Langerhans cell histiocytosis is usually effective, but some patients are refractory to treatment or develop toxicity. Thus, there is a need for innovative therapies. Recently, some cases of Langerhans cell histiocytosis were reported to express platelet-derived growth factor receptors α and ß or c-KIT by immunohistochemistry, and some of these patients had a clinical response to imatinib mesylate. Other hematologic disorders with PDGFRα or PDGFRß gene rearrangements also have responded to imatinib mesylate. The aim of this study was to evaluate immunohistochemical and molecular markers in Langerhans cell histiocytosis that would identify cases for possible treatment with tyrosine kinase inhibitors. We investigated formalin-fixed, paraffin-embedded tissue sections from 14 cases of Langerhans cell histiocytosis. As controls, we included cases of inflammatory dermatitis (n = 5) and dermatopathic lymphadenitis (n = 7). We performed immunohistochemistry for S100, CD1a, c-KIT, and platelet-derived growth factor receptors α and ß. Fluorescence in situ hybridization analysis to detect rearrangements of the PDGFRα or PDGFRß genes was also performed. Four (28.5%) of 14 cases of Langerhans cell histiocytosis were positive for platelet-derived growth factor receptor α, whereas absent/weak expression was seen in 10 cases and all controls. All cases were negative for platelet-derived growth factor receptor ß and c-KIT. The fluorescence in situ hybridization studies were also negative in all 8 cases with adequate quality DNA. Our findings suggest that a subset of cases of Langerhans cell histiocytosis may be treated with tyrosine kinase inhibitors due to the expression of platelet-derived growth factor receptor α. Clinical trials that evaluate the use of tyrosine kinase inhibitors in Langerhans cell histiocytosis seem warranted and should evaluate these markers.

Characterization of six novel patients with MECP2 duplications due to unbalanced rearrangements of the X chromosome.

Males with duplication of the Xq28 region, including methyl CpG-binding protein 2 (MECP2), exhibit a characteristic phenotype, including developmental delay, intellectual disability, limited or absent speech, limited or absent ambulation, and recurrent respiratory infections. We report six males with MECP2 duplications identified using array comparative genomic hybridization. The minimal sizes of these duplications range from ∼0.08 to 14.13 Mb, which, to the best of our knowledge, are respectively the smallest and largest minimal size duplications molecularly characterized to date. Adjunct metaphase fluorescence in situ hybridization analysis further classified these duplications as tandem or as products of complex chromosomal rearrangements. Specifically, one complex rearrangement was described as a der(12)t(X;12)(q28;q24.33), which is the first report of a translocation involving MECP2 on Xq and chromosome 12. The other complex rearrangement was described as a rec(X)dup(Xq)inv(X)(p22.32q28)mat. Synthesis of the dysmorphic features identified in individuals with rec(X) chromosomes, including deletions in the pseudoautosomal region 1 (PAR1) at Xp22.33/Yp11.3 and duplications of the distal Xq region including MECP2, revealed a high prevalence of undescended testes (7/8) and micropenis (3/8) in this cohort. Given that micropenis is rare in the general population, but present in 38% of individuals in this cohort, a dosage anomaly at one or both loci may be a significant risk factor for this condition. Therefore, we recommend microarray testing for patients with unexplained micropenis, particularly when accompanied by other phenotypic anomalies.

A novel t(6;13)(q15;q34) translocation in a giant cell reparative granuloma (solid aneurysmal bone cyst).

Aneurysmal bone cyst is a rapidly growing and locally aggressive lesion that commonly affects children and young adults. Initially regarded as a reactive process, primary aneurysmal bone cyst is now widely accepted as a neoplasm owing to recent findings of recurrent clonal chromosomal alterations, mostly t(16;17)(q22;p13). However, other infrequent chromosomal rearrangements have also been reported. Giant cell reparative granuloma, previously regarded as a nonneoplastic process and histologically indistinguishable from the solid variant of aneurysmal bone cyst, is frequently seen in the gnathic bones and the short tubular bones of the hands and feet. Here we present such a case of giant cell reparative granuloma (solid aneurysmal bone cyst) in the finger of a 63-year-old white man. Cytogenetic analysis revealed a novel alteration involving a reciprocal translocation between 6q and 13q, with a karyotype of 46,XY,t(6;13)(q15;q34),del(20)(q13.1).

Primary follicular lymphoma of the testis in children and adolescents.

This study reports 6 cases of primary follicular lymphoma of the testis (PFLT) in children and adolescents correlated with clinical presentation, pathologic features, treatment, and outcome. All 6 patients (age, 3 to 16 y; median, 4 y) had PFLT grade 3 with disease limited to the testis, completely resected and treated with 2 courses of chemotherapy (cyclophosphamide, vincristine, prednisone, doxorubicin). Event-free survival was 100% (follow-up: median, 73 mo; mean, 53 mo; range, 6 to 96 mo). In conclusion, clinical outcome in children and adolescents with PFLT is excellent with treatment including complete surgical resection and 2 courses of cyclophosphamide, vincristine, prednisone, doxorubicin.

Algorithmic approach for methyl-CpG binding protein 2 (MECP2) gene testing in patients with neurodevelopmental disabilities.

Methyl-CpG binding protein 2 gene (MECP2) testing is indicated for patients with numerous clinical presentations, including Rett syndrome (classic and atypical), unexplained neonatal encephalopathy, Angelman syndrome, nonspecific mental retardation, autism (females), and an X-linked family history of developmental delay. Because of this complexity, a gender-specific approach for comprehensive MECP2 gene testing is described. Briefly, sequencing of exons 1 to 4 of MECP2 is recommended for patients with a Rett syndrome phenotype, unexplained neonatal encephalopathy, an Angelman syndrome phenotype (with negative 15q11-13 analysis), nonspecific mental retardation, or autism (females). Additional testing for large-scale MECP2 deletions is recommended for patients with Rett syndrome or Angelman syndrome phenotypes (with negative 15q11-13 analysis) following negative sequencing. Alternatively, testing for large-scale MECP2 duplications is recommended for males presenting with mental retardation, an X-linked family history of developmental delay, and a significant proportion of previously described clinical features (particularly a history of recurrent respiratory infections).