Myeloid neoplasms secondary to plasma cell myeloma: an intrinsic predisposition or therapy-related phenomenon? A clinicopathologic study of 41 cases and correlation of cytogenetic features with treatment regimens.

We describe 41 cases of myeloid neoplasms (MNs) secondary to plasma cell myeloma (PCM). The types of MN included myelodysplastic syndrome (MDS) in 34 (82.9%), acute myeloid leukemia (AML) in 4 (9.

MLL duplication in a pediatric patient with B-cell lymphoblastic lymphoma.

Lymphoblastic lymphoma is the second most common type of non-Hodgkin lymphoma seen in children. Approximately, 90% of lymphoblastic lymphomas arise from T cells, with the remaining 10% being B-cell-lineage derived. Although T-cell lymphoblastic lymphoma most frequently occurs in the anterior mediastinum (thymus), B-cell lymphoblastic lymphoma (B-LBL) predominates in extranodal sites such as skin and bone.

SET oncoprotein overexpression in B-cell chronic lymphocytic leukemia and non-Hodgkin lymphoma: a predictor of aggressive disease and a new treatment target.

B-cell chronic lymphocytic leukemia (CLL), an incurable leukemia, is characterized by defective apoptosis. We found that the SET oncoprotein, a potent inhibitor of the protein phosphatase 2A (PP2A) tumor suppressor, is overexpressed in primary CLL cells and B-cell non-Hodgkin lymphoma (NHL) cell line cells. In CLL, increased levels of SET correlated significantly with disease severity (shorter time to treatment and overall survival).

College of American Pathologists/American College of Medical Genetics proficiency testing for constitutional cytogenomic microarray analysis.

Purpose: To evaluate the feasibility of administering a newly established proficiency test offered through the College of American Pathologists and the American College of Medical Genetics for genomic copy number assessment by microarray analysis, and to determine the reproducibility and concordance among laboratory results from this test.

Methods: Surveys were designed through the Cytogenetic Resource Committee of the two colleges to assess the ability of testing laboratories to process DNA samples provided and interpret results. Supplemental questions were asked with each Survey to determine laboratory practice trends.

Donor cell leukemia in umbilical cord blood transplant patients: a case study and literature review highlighting the importance of molecular engraftment analysis.

Donor cell neoplasms are rare complications of treatment regimens that involve stem cell transplantation for hematological malignancies, myelodysplastic processes, or certain genetic or metabolic disorders. We report a case of donor cell leukemia in a pediatric patient with a history of acute myeloid leukemia that manifested as recurrent AML FAB type M5 fourteen months after umbilical cord blood transplantation. Although there was some immunophenotypic drift from the patient's original AML and their posttransplant presentation, the initial pathological impression was of recurrent disease.

A single tube, four-color flow cytometry assay for evaluation of ZAP-70 and CD38 expression in chronic lymphocytic leukemia.

We describe a simple and robust flow cytometry assay for ZAP-70 and CD38 expression. The steps required to validate this assay in a clinical flow cytometry laboratory are described. Two criteria were used to characterize ZAP-70 expression into positive, negative, and indeterminate categories and applied to 111 cases of chronic lymphocytic leukemia (CLL) resulting in 29.

A genomic approach to improve prognosis and predict therapeutic response in chronic lymphocytic leukemia.

Purpose: Chronic lymphocytic leukemia (CLL) is a B-cell malignancy characterized by a variable clinical course. Several parameters have prognostic capabilities but are associated with altered response to therapy in only a small subset of patients.

Experimental Design: We used gene expression profiling methods to generate predictors of therapy response and prognosis.

Reduced ATR or Chk1 expression leads to chromosome instability and chemosensitization of mismatch repair-deficient colorectal cancer cells.

Genomic instability in colorectal cancer is categorized into two distinct classes: chromosome instability (CIN) and microsatellite instability (MSI). MSI is the result of mutations in the mismatch repair (MMR) machinery, whereas CIN is often thought to be associated with a disruption in the APC gene. Clinical data has recently shown the presence of heterozygous mutations in ATR and Chk1 in human cancers that exhibit MSI, suggesting that those mutations may contribute to tumorigenesis.

Clinicopathologic findings in high-grade B-cell lymphomas with typical Burkitt morphologic features but lacking the MYC translocation.

In the World Health Organization classification, cases with classical Burkitt morphologic features and a very high proliferation fraction but without the MYC translocation are not clearly designated as a separate entity and are usually categorized as diffuse large B-cell lymphoma (DLBCL). We identified from our records 33 cases of highly aggressive mature B-cell neoplasms from 8 children and 25 adults with typical Burkitt cytomorphologic, histologic, and immunophenotypic (CD20+/CD10+ and surface immunoglobulin-positive) features. Rearrangement of MYC (MYC+) was present in only 18 of 33 cases, but the proliferation fraction was more than 90% in all MYC-cases (no MYC rearrangement).

Clinical and molecular predictors of disease severity and survival in chronic lymphocytic leukemia.

Several parameters may predict disease severity and overall survival in chronic lymphocytic leukemia (CLL). The purpose of our study of 190 CLL patients was to compare immunoglobulin heavy chain variable region (IgV(H)) mutation status, cytogenetic abnormalities, and leukemia cell CD38 and Zap-70 to older, traditional parameters. We also wanted to construct a simple, inexpensive prognosis score that would significantly predict TTT and survival in patients at the time of diagnosis and help practicing clinicians.

Morphologic examination of sequential bone marrow biopsies after nonmyeloablative stem cell transplantation complements molecular studies of donor engraftment.

Context: Nonmyeloablative stem cell transplantation (NMSCT) is a mode of immunotherapy increasingly employed in treating hematologic, lymphoid, and solid tumors. Patients are monitored principally by molecular analysis of donor engraftment.

Objective: To determine the role of morphologic examination of bone marrow after NMSCT.

Progressive immunoglobulin gene mutations in chronic lymphocytic leukemia: evidence for antigen-driven intraclonal diversification.

Somatic mutations of immunoglobulin genes characterize mature memory B cells, and intraclonal B-cell diversification is typically associated with expansion of B-cell clones with greater affinity for antigen (antigen drive). Evidence for a role of antigen in progression of intraclonal chronic lymphocytic leukemia (CLL) cell diversification in patients with mutated immunoglobulin genes has not been previously presented. We performed a single-cell analysis of immunoglobulin heavy and light chains in 6 patients with somatically mutated CLL-cell immunoglobulin genes and identified 2 patients with multiple related (oligoclonal) subgroups of CLL cells.

Genetically characterized positive control cell lines derived from residual clinical blood samples.

Background: Positive control materials for clinical diagnostic molecular genetic testing are in critically short supply. High-quality DNA that closely resembles DNA isolated from patient specimens can be obtained from Epstein-Barr virus (EBV)-transformed peripheral blood lymphocyte cell lines. Here we report the development of a process to (a) recover residual blood samples with clinically important mutations detected during routine medical care, (b) select samples likely to provide viable lymphocytes for EBV transformation, (c) establish stable cell lines and confirm the reported mutation(s), and (d) validate the cell lines for use as positive controls in clinical molecular genetic testing applications.

Triploid mosaicism in a 45,X/69,XXY infant.

We report on an infant referred for chromosome analysis during the neonatal period due to ambiguous genitalia. The genitalia appeared male with bilaterally palpable testes, penoscrotal hypospadias, chordee, and a bifid scrotum. Chromosome analysis and interphase FISH analysis of lymphocytes showed a 45,X karyotype and no evidence for SRY in 200 nuclei examined, respectively.

Pelger-Huët anomaly in a child with 1q42.3-44 deletion.

Congenital Pelger-Huët anomaly (PHA) is an autosomal dominant disorder characterized by hypolobulated neutrophils with coarse clumping of the nuclear chromatin. PHA has been recently linked to the gene encoding the lamin B receptor, located at chromosome 1q41-43. The authors report a case of PHA in a child with interstitial deletion of the 1q subtelomeric region (1q42.

The value of fluorescence in situ hybridization and polymerase chain reaction in the diagnosis of B-cell non-Hodgkin lymphoma by fine-needle aspiration.

Context: Molecular genetic analyses have been predicted to improve the diagnostic accuracy of fine-needle aspiration of B-cell non-Hodgkin lymphoma.

Objective: To determine the value of routine molecular genetic assays, polymerase chain reaction (PCR) and fluorescence in situ hybridization (FISH), in the diagnosis of B-cell non-Hodgkin lymphoma by fine-needle aspiration (FNA).

Design: A multiparametric method, including cytology, flow cytometry, PCR, and FISH, was prospectively evaluated in the diagnosis of B-cell non-Hodgkin lymphoma by FNA.

ATR functions as a gene dosage-dependent tumor suppressor on a mismatch repair-deficient background.

The ataxia-telangiectasia mutated and rad3-related (ATR) kinase orchestrates cellular responses to DNA damage and replication stress. Complete loss of ATR function leads to chromosomal instability and cell death. However, heterozygous ATR mutations are found in human cancers with microsatellite instability, suggesting that ATR haploinsufficiency contributes to tumorigenesis.

Molecular and cytogenetic characterization of a novel translocation t(4;22) involving the breakpoint cluster region and platelet-derived growth factor receptor-alpha genes in a patient with atypical chronic myeloid leukemia.

We report a case of BCR-ABL-negative atypical chronic myeloid leukemia (CML) with translocation t(4;22) (q12;q11.2) juxtaposing the breakpoint cluster region (BCR) and platelet-derived growth factor receptor-alpha (PDGFRA) genes. The patient was a 57-year-old man with a history of stage IV diffuse large B-cell lymphoma, status post-6 cycles of combination chemotherapy in 1999, who presented in August 2002 with enlarged lymph nodes, anemia, and marked leukocytosis (50 x 10(9) g/dL) consistent with a myeloproliferative disorder (MPD).

Increased risk for developmental delay in Saethre-Chotzen syndrome is associated with TWIST deletions: an improved strategy for TWIST mutation screening.

The majority of patients with Saethre-Chotzen syndrome have mutations in the TWIST gene, which codes for a basic helix-loop-helix transcription factor. Of the genetic alterations identified in TWIST, nonsense mutations, frameshifts secondary to small deletions or insertions, and large deletions implicate haploinsufficiency as the pathogenic mechanism. We identified three novel intragenic mutations and six deletions in our patients by using a new strategy to screen for TWIST mutations.

Molecular cytogenetic characterization of a subtle interstitial del(3)(p25.3p26.2) in a patient with deletion 3p syndrome.

Deletion 3p syndrome is associated with characteristic facial features, growth failure, and mental retardation. Typically, individuals with deletion 3p syndrome have terminal deletions that result in loss of material from 3p25 to 3pter. We present a child with a clinical phenotype consistent with deletion 3p syndrome (ptosis, microcephaly, growth retardation, and developmental delay) and a subtle interstitial deletion in the distal portion of the short arm of chromosome 3, del(3)(p25.