Implementation of cytogenomic microarray with plasma cell enrichment enables better abnormality detection and risk stratification in patients with plasma cell neoplasia than conventional cytogenetics and fluorescence in situ hybridization.

The detection of chromosomal abnormalities is important in the diagnosis, prognosis and disease monitoring in plasma cell neoplasia (PCN). However, the gold standard diagnostic techniques of conventional cytogenetics (CC) and fluorescence in situ hybridization (FISH) are hampered by culture difficulties and probe availability. Cytogenomic microarray (CMA), however, is able to surmount such limitations and generate a comprehensive genomic profile with the implementation of plasma cell (PC) enrichment. In this study, we examined 89 bone marrow specimens with CC and FISH without PC enrichment, 35 of which were examined with CMA after PC enrichment. Results revealed that after PC enrichment, CMA was able to detect chromosomal abnormalities in 34 of 35 specimens tested (97.1%), compared to 21 and 32 specimens (60% and 91.4%, respectively) achieved by CC and FISH, respectively, which were similar to the abnormality detection rates among all 89 specimens (59.5% by CC and 92.1% by FISH). In addition, as the only technique capable of detecting copy neutral loss of heterozygosity (CN-LOH) and chromothripsis, CMA appears to be the most powerful tool in risk stratification as it successfully re-stratified 9 (25.7%) and 12 (34.3%) specimens from standard risk (determined by CC and FISH, respectively) to high risk. Based on the encouraging data presented by our study and others, we conclude that implementation of CMA with PC enrichment is of great value in routine clinical workup in achieving a more complete genetic profile of patients with PCN.

Chromosomal microarray analysis is superior in identifying cryptic aberrations in patients with acute lymphoblastic leukemia at diagnosis/relapse as a single assay.

INTRODUCTION: Conventional cytogenetics (CC) is important in diagnosis, therapy, monitoring of post-transplant bone marrow, and prognosis assessment of acute lymphoblastic leukemia (ALL). However, due to the nature of ALL, CC often encounters difficulties of complex karyotype, poor chromosome morphology, low mitotic index, or normal cells dividing only. In contrast, chromosomal microarray analysis (CMA) showed a specificity >99% and a sensitivity of 100% in chronic lymphocytic leukemia (CLL) patients. Here, we report our experience with CMA on adult ALL patients. METHODS: Thirty-three bone marrow/blood samples from ALL patients (aged 18-79 years, median 44) at diagnosis/relapse, analyzed by CC and/or fluorescence in situ hybridization (FISH), were recruited. Chromosomal microarray analysis results were compared with CC. Fluorescence in situ hybridization analysis, if available, was applied when there was a discrepancy. RESULTS: Copy-neutral loss-of-heterozygosity (CN-LOH) was found in 8 cases (24.2%). Only CN-LOH at 9p was recurrent (3 cases, 9.1%). Copy number alterations (CNAs) were detected in 6 of 9 cases (66.7%) with normal karyotypes, in 3 of 5 cases (60.0%) with sole "balanced" translocations, and in 18 of 19 cases (94.7%) with complex karyotypes. Common CNAs involved CDKN2A/2B (30.3%), IKZF1 (27.3%), PAX5 (9.1%), RB1 (9.1%), BTG1 (6.7%), and ETV6 (6.7%), which regulate cell cycle, B lymphopoiesis, or act as tumor suppressors in ALL. Copy number alteration detection rate by CMA was 81.8% (27 of 33 cases) as compared to 57.6% (19 of 33 cases) by CC. CONCLUSION: Incorporation of CMA as a routine clinical test at the time of diagnosis/relapse, in conjunction with CC and/or FISH, is highly recommended.

Amplification of 1q21 and other abnormalities in multiple myeloma patients from a tertiary hospital in singapore.

Much effort has been made to stratify multiple myeloma patients for targeted therapy. However, responses have been varied and improved patient stratifications are needed. Forty-five diagnostic samples from multiple myeloma patients (median age 65 years) were stratified cytogenetically as 15 having non-hyperdiploidy, 20 having hyperdiploidy and 10 having a normal karyotype. Fluorescence in situ hybridization (FISH) assays with FGFR3/IGH, CCND1/IGH, IGH/MAF, RB1 and TP53 probes on bone marrow samples showed that IGH rearrangements were the most common abnormality in the non-hyperdiploid group but these were also found among hyperdiploid patients and patients with normal cytogenetics. Of these, FGFR3/IGH rearrangements were most frequent. Deletion of RB1/monosomy 13 was the most common genetic abnormality across the three groups and was significantly higher among non-hyperdiploid compared to hyperdiploid patients. On the other hand, the study recorded a low incidence of TP53 deletion/monosomy 17. The FGFR3/IGH fusion was frequently seen with RB1 deletion/monosomy 13. FISH with 1p36/1q21 and 6q21/15q22 probes showed that amplification of 15q22 was seen in all of the hyperdiploid patients while amplification of 1q21, Amp(1q21), characterized non-hyperdiploid patients. In contrast, deletions of 1p36 and 6q21 were very rare events. Amp(1q21), FGFR3/IGH fusion, RB1 deletion/monosomy 13, and even TP53 deletion/monosomy 17 were seen in some hyperdiploid patients, suggesting that they have a less than favorable prognosis and require closer monitoring.

CpG Oligonucleotide and Interleukin 2 stimulation enables higher cytogenetic abnormality detection rates than 12-o-tetradecanolyphorbol-13-acetate in Asian patients with B-cell chronic lymphocytic leukemia (B-CLL).

The present study was designed to compare abnormality detection rates using DSP30 + IL2 and 12-O-Tetradecanoylphorbol-13-acetate (TPA) in Asian patients with B-CLL. Hematological specimens from 47 patients (29 newly diagnosed, 18 relapsed) were established as 72 h-DSP30 + IL2 and TPA cultures. Standard methods were employed to identify clonal aberrations by conventional cytogenetics (CC). The B-CLL fluorescence in situ hybridization (FISH) panel comprised ATM, CEP12, D13S25, and TP53 probes. DSP30 + IL2 cultures had a higher chromosomal abnormality detection rate (67 %) compared to TPA (44 %, p < 0.001). The mean number of analyzable metaphases and abnormal metaphases per slide was also higher (p < 0.005, p < 0.001, respectively). Culture success rate, percentage of complex karyotype, and percentage of non-clonal abnormal cell were not significantly different (p > 0.05). Thirteen cases with abnormalities were found exclusively in DSP30 + IL2 cultures compared to one found solely in TPA cultures. DSP30 + IL2 cultures were comparable to the FISH panel in detecting 11q-, +12 and 17p- but not 13q-. It also has a predilection for 11q- bearing leukemic cells compared to TPA. FISH had a higher abnormality detection rate (84.1 %) compared to CC (66.0 %) with borderline significance (p = 0.051), albeit limited by its coverage. In conclusion, DSP30 + IL2 showed a higher abnormality detection rate. However, FISH is indispensable to circumvent low mitotic indices and detect subtle abnormalities.

Cytogenetic and molecular aberrations of multiple myeloma patients: a single-center study in Singapore.

BACKGROUND: Much is known about the cytogenetic lesions that characterize multiple myeloma (MM) patients from the USA, Europe, and East Asia. However, little has been published about the disease among Southeast Asians. The aim of this study was to determine the chromosomal abnormalities of MM patients in our Singapore population. METHODS: Forty-five newly-diagnosed, morphologically confirmed patients comprising 18 males and 27 females, aged 46 - 84 years (median 65 years) were investigated by karyotyping and fluorescence in situ hybridization (FISH). FISH employing standard panel probes and 1p36/1q21 and 6q21/15q22 probes was performed on diagnostic bone marrow samples. RESULTS: Thirty-four cases (75.6%) had karyotypic abnormalities. Including FISH, a total detection rate of 91.1% was attained. Numerical and complex structural aberrations were common to both hyperdiploid and non-hyperdiploid patients. Numerical gains of several recurring chromosomes were frequent among hyperdiploid patients while structural rearrangements of several chromosomes including 8q24.1 and 14q32 characterized non-hyperdiploid patients. With FISH, immunoglobulin heavy chain (IGH) gene rearrangements, especially fibroblast growth factor receptor 3 (FGFR3)/IGH and RB1 deletion/monosomy 13 were the most common abnormalities (43.4%). Amplification 1q21 was 10 times more frequent (42.5%) than del(1p36) and del(6q21). CONCLUSIONS: We have successfully reported the comprehensive cytogenetic profiling of a cohort of newly-diagnosed myeloma patients in our population. This study indicates that the genetic and cytogenetic abnormalities, and their frequencies, in our study group are generally similar to other populations.

Bone marrow cytogenetics workup: Application of lean management system to determine if additional cell workup is helpful and necessary to analysis.

INTRODUCTION: High workload volumes in a Cytogenetics laboratory can lead to long result turn-around times (TAT). This study aimed to improve laboratory efficiency by adopting Lean Management System initiatives to increase productivity through the elimination of wastes. This study examined if the prerequisite 20-cell analysis was sufficient for a conclusive result or if additional cell workup was necessary to ascertain the presence of a previous chromosome abnormality among cases on follow-up, or when a single abnormal cell was encountered during the analysis to determine the presence of a clone. MATERIALS AND METHODS: The karyotype results of cases that had additional workup were retrieved from among 8040 bone marrow cases of various haematological disorders performed between June 2003 and June 2008. RESULTS: Of 8040 cases analysed, 2915 cases (36.3%) had additional cell workup. Only 49 cases (1.7%) led to the establishment of a clone. The majority of these cases could have been resolved without the additional workup, especially if fluorescence in situ hybridization (FISH) or polymerase chain reaction (PCR)-based assays had been utilised. CONCLUSION: This study shows that the additional workup procedure is redundant. The time saved by discontinuing the workup procedure can be used to analyse other cases, leading to increased laboratory efficiency and a faster TAT without compromise to patient care. The practice of additional workup over and above the 20- cell analysis should be dispensed with as little benefit was derived for the amount of additional manpower expended. FISH or PCR-based assays should be utilised to elucidate a case further.

Occurrence of trisomy 12, t(14;18)(q32;q21), and t(8;14)(q24.1;q11.2) in a patient with B-cell chronic lymphocytic leukemia.

Trisomy 12, t(14;18)(q32;q21), and t(8;14)(q24.1;q11.2) were found in a 59-year-old man with B-cell chronic lymphocytic leukemia (CLL). While trisomy 12 is one of the most common cytogenetic abnormalities in chronic lymphocytic leukemia, the t(14;18) rearrangement has a strong association with follicular lymphoma and the t(8;14) is associated with T-cell neoplasia. Occurrence of these three abnormalities in CLL are rare, and the significance of this finding is unclear. Further studies of similar cases may shed additional insight into this finding.

Loss of the extra chromosome 21 in a patient with Down syndrome and myelodysplasia.

Monosomy 21 is a rare acquired karyotypic abnormality associated with myeloid disorders. Occurrence of loss of one chromosome 21 in the background of trisomy 21 in Down syndrome, resulting in the pseudo-normalization of trisomy 21, is a novel finding. The case is described of a patient with Down syndrome who acquired such a genetic abnormality as a result of myelodysplastic syndrome.

Cytogenetic alterations in renal tumors: a study of 38 Southeast Asian patients.

Renal cell carcinoma (RCC) is the most common cancer of the kidney. Cytogenetic studies of renal cell carcinoma have provided valuable insight into the chromosomal abnormalities involved in the genesis and progression of the disease, and have also helped in the classification of these tumors. Our objectives were to identify nonrandom chromosome abnormalities in renal tumors in a Southeast Asian population and also to determine if they differ from those in Western populations. Structural rearrangements of 3p were specific for clear cell RCC, with the most consistent structural rearrangement being a translocation between 3p13 and 5q22. Gains of chromosomes 7 and 17 were observed in three and two cases of papillary RCC, respectively. All male patients with papillary RCC were noted to have loss of the Y chromosome. Gains of chromosomes 3 and 7, and structural aberration of chromosome 3, were observed in patients with transitional cell carcinoma of the renal pelvis (TCC). Chromosomal abnormalities in clear cell RCC, papillary RCC, and TCC did not differ between the Southeast Asian and Western populations. The aberrations seem to be common sporadic events, both geographically and racially.

Trisomy 8 as sole cytogenetic abnormality in a case of chronic lymphocytic leukemia.

A 49-year-old man, who had been diagnosed with chronic lymphocytic leukemia (CLL) in 2002, had a normal karyotype in his bone marrow. Trisomy 8 was demonstrated in his peripheral blood in 2005. Fluorescence in situ hybridization using an LSI CEP 8 probe performed on the archival bone marrow specimen showed three hybridization signals in 40% of 200 interphase cells scored. This confirmed that the trisomy 8 abnormality was present in both the blood and bone marrow samples. Trisomy 8 as the sole chromosomal abnormality in CLL is a very rare finding. The prognostic significance of trisomy 8 in CLL remains to be seen.

Primary pleural synovial sarcoma. A case report and review of the literature.

Synovial sarcoma (SS) is an uncommon soft tissue tumor that occurs primarily in the extremities of young adults, especially in the periarticular region. In this report, we describe the rare occurrence of primary SS of the pleura in a 15-year-old boy. Histologically, the tumor demonstrated monophasic morphologic findings and showed positive staining with vimentin and Bcl-2 and focally for cytokeratin CK7. Fluorescent in situ hybridization identified t(X;18) translocation. The patient developed recurrences 20 months following resection of the tumor. The literature on this uncommon entity is reviewed, and its histogenesis, differential diagnoses, and cytologic features are also discussed.