Dermatofibrosarcoma protuberans: a clinicopathological, immunohistochemical, genetic (COL1A1-PDGFB), and therapeutic study of low-grade versus high-grade (fibrosarcomatous) tumors

BACKGROUND

Dermatofibrosarcoma protuberans (DFSP) is an uncommon cutaneous tumor, usually low grade, except for the fibrosarcomatous variant (DFSP-FS).

OBJECTIVES

We sought to compare the clinicopathological, immunohistochemical, genetic, and therapeutic features between DFSP and DFSP-FS.

METHODS

The clinicopathological features were reviewed in 63 DFSP and 12 DFSP-FS. Immunohistochemistry and multiplex reverse transcriptase-polymerase chain reaction were carried out using formalin-fixed, paraffin-embedded tissue, using specific primers for collagen type I alpha 1 (COL1A1) and platelet-derived growth factor beta (PDGFB).

RESULTS

DFSP-FS was associated with tumor history longer than 5 years (P = .009), tumor size greater than 4 cm (P = .001), more stages of modified Mohs micrographic surgery (P = .005), expansive subcutaneous infiltration (P = .005), muscular invasion (P = .0001), absence of CD34 staining (P = .018), p53 positivity (P = .006), and increased proliferative activity (P = .004) compared with DFSP. The COL1A1-PDGFB fusion transcript was found in 100% DFSP-FS and 72% DFSP. No association was found between the different COL1A1-PDGFB fusion transcripts and the different histologic subtypes. Wide local excision (2 cm) was performed in 47% of cases and modified Mohs micrographic surgery in 53%. After a mean follow-up of 73 months (range 21-235), 6 patients had local recurrence (5 DFSP, 1 DFSP-FS) and one died of disease (DFSP-FS). The only factor related to local recurrence was the type of surgery (17% wide local excision vs 0% modified Mohs micrographic surgery) (P = .006).

LIMITATIONS

Our study is retrospective. Prospective studies are necessary to confirm our results.

CONCLUSIONS

DFSP-FS reflects tumor progression in DFSP, with larger size, particular invasive patterns, p53 expression, and increased proliferative activity. However, as in low-grade DFSP, appropriate surgery permits a tumor-free excision. COL1A1-PDGFB is a useful tool for diagnosis of DFSP and particularly for DFSP-FS.

[Multiprobe fluorescence in situ hybridization panel in detection of the common cytogenetic abnormalities of acute myeloid leukemia]

AIM

To evaluate the value of multiprobe Fluorescence in situ hybridization (FISH) panel in detection of the common cytogenetic abnormalities in acute myeloidleukemia( AML). And to investigate its association with clinical diagnosis, chemotherapy and prognosis.

METHODS

Using the multiprobe AML/MDS panel designed to detect upto eight different FISH probes, which was for AML1/ETO transfusion gene, PML-RARα transfusion gene, CBFβ/MYH11 transfusion gene, MLL breakapart, P53 deletion,Del(5q), Del(7q), Del(20q), 40 cases of AML were investigated. The conventional karyotype analysis and the in-formation about the treatment responses were also used for assessing.

RESULTS

22 of the 40 AML cases were found to carry 7 types of cytogenetic abnormalities by multiprobe FISH panel including AML1/ETO transfusion gene, PML-RARa transfusion gene, MLL breakapart, P53 deletion, Del (5q), Del7q and trisomy 8. However conventional karyotype analysis only discovered 11 cases with the corresponding cytogenetic abnormalities, the positive ratio was 57.5% in multiprobe FISH panel higher than that in karyotype analysis (27.50%). Patiens with AML1/ETO or PML-RARa transfusion gene are easily to reach CR in the first induction chemotherapy, while the Del(7q), MLL breakapart, complex cytogenetic abnormalities may indicate poor prognosis.

CONCLUSION

Mutiprobe FISH panel is more rapid, accurate and effective for detecting the common cytogenetic abnormalities in AML, compared with the conventional karyotype analysis and common FISH analysis.

[Detection of ALK positive pulmonary adenocarcinoma using immunostaining]

Although ALK-positive lung cancer cases have been recently reported, it is impossible to detect using only morphology technique. Furthermore, though RT-PCR and FISH techniques can be used for detection, they are not practical for screening. We investigated whether ALK-positive lung cancer could be detected using a conventional immunostaining method. Resected lung adenocarcinoma samples from 88 nonsmoker cases were selected and screening was performed using ALK immunostaining in 24 cases that did not have the EGFR or k-ras mutation. We found that the optimal staining condition was treatment using a water bath and detection with a Novo Link Polymer Detection System (Leica microsystems). Of the 24 cases examined, ALK expression was found in 4, of which ALK separated signals were found in 3 using a FISH method. No separated signals were seen in cases with negative immunostaining findings. Detection by immunostaining was found useful for ALK mutated lung cancer cases, though the pretreatment and detection methods utilized are important.

[Primary pulmonary synovial sarcoma confirmed by gene expression analysis]

We report a patient who was diagnosed with synovial sarcoma based on gene expression analysis. A 39-year-old male visited a local hospital due to left chest pain. Chest compued tomography (CT) showed a lung tumor located mainly at the lingula of the left lung, and extending to the bifurcation of the upper and lower lobar bronchi. Left pneumonectomy was performed. Pathological examination showed a mesenchymal tumor consisting of short-spindle, small, round cells, and the differentiation between synovial sarcoma and peripheral neuroectodermal tumor was necessary. RT-PCR to examine the gene expression of cells revealed a SYT-SSX fusion gene, and a diagnosis of primary synovial sarcoma of the lung was made.

Human prostate sphere-forming cells represent a subset of basal epithelial cells capable of glandular regeneration in vivo

BACKGROUND

Prostate stem/progenitor cells function in glandular development and maintenance. They may be targets for tumor initiation, so characterization of these cells may have therapeutic implications. Cells from dissociated tissues that form spheres in vitro often represent stem/progenitor cells. A subset of human prostate cells that form prostaspheres were evaluated for self-renewal and tissue regeneration capability in the present study.

METHODS

Prostaspheres were generated from 59 prostatectomy specimens. Lineage marker expression and TMPRSS-ERG status was determined via immunohistochemistry and fluorescence in situ hybridization (FISH). Subpopulations of prostate epithelial cells were isolated by cell sorting and interrogated for sphere-forming activity. Tissue regeneration potential was assessed by combining sphere-forming cells with rat urogenital sinus mesenchyme (rUGSM) subcutaneously in immunocompromised mice.

RESULTS

Prostate tissue specimens were heterogeneous, containing both benign and malignant (Gleason 3-5) glands. TMPRSS-ERG fusion was found in approximately 70% of cancers examined. Prostaspheres developed from single cells at a variable rate (0.5-4%) and could be serially passaged. A basal phenotype (CD44+CD49f+CK5+p63+CK8-AR-PSA-) was observed among sphere-forming cells. Subpopulations of prostate cells expressing tumor-associated calcium signal transducer 2 (Trop2), CD44, and CD49f preferentially formed spheres. In vivo implantation of sphere-forming cells and rUGSM regenerated tubular structures containing discreet basal and luminal layers. The TMPRSS-ERG fusion was absent in prostaspheres derived from fusion-positive tumor tissue, suggesting a survival/growth advantage of benign prostate epithelial cells.

CONCLUSION

Human prostate sphere-forming cells self-renew, have tissue regeneration capability, and represent a subpopulation of basal cells.

Bone marrow mesenchymal stem cells from infants with MLL-AF4+ acute leukemia harbor and express the MLL-AF4 fusion gene

MLL-AF4 fusion is a hallmark genetic abnormality in infant B-acute lymphoblastic leukemia (B-ALL) known to arise in utero. The cellular origin of leukemic fusion genes during human development is difficult to ascertain. The bone marrow (BM) microenvironment plays an important role in the pathogenesis of several hematological malignances. BM mesenchymal stem cells (BM-MSC) from 38 children diagnosed with cytogenetically different acute leukemias were screened for leukemic fusion genes. Fusion genes were absent in BM-MSCs of childhood leukemias carrying TEL-AML1, BCR-ABL, AML1-ETO, MLL-AF9, MLL-AF10, MLL-ENL or hyperdiploidy. However, MLL-AF4 was detected and expressed in BM-MSCs from all cases of MLL-AF4(+) B-ALL. Unlike leukemic blasts, MLL-AF4(+) BM-MSCs did not display monoclonal Ig gene rearrangements. Endogenous or ectopic expression of MLL-AF4 exerted no effect on MSC culture homeostasis. These findings suggest that MSCs may be in part tumor-related, highlighting an unrecognized role of the BM milieu on the pathogenesis of MLL-AF4(+) B-ALL. MLL-AF4 itself is not sufficient for MSC transformation and the expression of MLL-AF4 in MSCs is compatible with a mesenchymal phenotype, suggesting a differential impact in the hematopoietic system and mesenchyme. The absence of monoclonal rearrangements in MLL-AF4(+) BM-MSCs precludes the possibility of cellular plasticity or de-differentiation of B-ALL blasts and suggests that MLL-AF4 might arise in a population of prehematopoietic precursors.

Detection of TMPRSS2-ERG fusion gene expression in prostate cancer specimens by a novel assay using branched DNA

OBJECTIVES

To develop a novel assay that uses branched DNA technology to measure TMPRSS2-ERG fusion, as genetic rearrangement of TMPRSS2 regulatory sequences and coding sequences of the ERG gene has been detected in nearly half of prostate cancers, but quantitative assays to detect such TMPRSS2-ERG gene fusion have been limited to real-time polymerase chain reaction (PCR) techniques that rely on reverse transcriptase-based amplification.

METHODS

Branched DNA probes were designed to detect TMPRSS2-ERG gene fusion in prostate cancer cell lines. Nonquantitative nested reverse transcription (RT)-PCR and fluorescence in situ hybridization (FISH) were used to ascertain TMPRSS2-ERG gene fusion status in prostate tissues.

RESULTS

The branched DNA assay detected TMPRSS2-ERG gene fusion from less than 200 pg of prostate cancer RNA, whereas more than 600 pg of RNA was required for fusion gene detection by one step real-time RT-PCR. In evaluation of clinical prostatectomy specimens, the branched DNA assay showed a concordant detectable fusion signal in all 9 clinical samples that had fusion detected by nested RT-PCR or FISH. Moreover, branched DNA detected gene fusion in 2 of 16 prostate cancer tissue specimens that was not detected by FISH or nested RT-PCR.

CONCLUSIONS

Our findings demonstrate a branched DNA assay that is effective for detection of TMPRSS2-ERG gene fusion in prostate cancer clinical specimens, thus providing an alternative method to ascertain TMPRSS2-ERG gene fusion in human prostate cancer tissue.

Burkitt's Lymphoma of the Stomach: a Case Report with Molecular Cytogenetic Analysis

In 1974, a 28-year-old man presented with a 12 cm sized ulcerated tumor involving the middle third of the stomach, which was originally diagnosed as "lymphosarcoma". Clinical recurrence of the lymphoma resulted in rapidly progressing disease and the patient died 4 months after initial diagnosis. Retrospective work-up of the 29-year-old tumor blocks revealed the typical histologic appearance and phenotype (CD20, CD10, BCL-6 positive) of Burkitt's lymphoma (BL) with a proliferation rate of 95%. By fluorescence in situ hybridization (FISH). the tumor cells were shown to harbor an IGH-MYC fusion indicating the presence of the hallmark Burkitt-translocation t(8;14)(q24;q32). Considering the typical clinical features of BL requiring appropriate treatment regimes the case presented here highlights the importance of modern histopathologic and molecular cytogenetic techniques for the proper classification of such rare lymphomas presenting at atypical sites.

Prognostic implication of SYT-SSX fusion type and clinicopathological parameters for tumor-related death, recurrence, and metastasis in synovial sarcoma

The present study aimed to describe the distribution and features of the SYT-SSX fusion gene in Chinese patients with synovial sarcoma (SS), and to analyze the prognostic value of SYT-SSX fusion type and clinicopathological parameters for tumor-related death, recurrence, and metastasis in SS. SYT-SSX1 and SYT-SSX2 fusion transcripts were tested by reverse transcription-polymerase chain reaction in 141 formalin-fixed, paraffin-embedded SS. The prognostic implication of SYT-SSX fusion type and clinicopathological parameters were analyzed by univariate and multivariate survival analyses. SYT-SSX1 and SYT-SSX2 were detected in 50 (34.5%) and 91 (64.5%) tumors, respectively. SYT-SSX1 (risk ratio [RR] = 2.032, P = 0.004), larger tumor size (RR = 1.859, P = 0.008), and aggressive Fédération Nationale des Centers de Lutte Contre le Cancer grade (RR = 2.094, P = 0.001) were adverse predictors for disease-specific survival. However, SYT-SSX fusion type was not associated with local recurrence-free survival (P = 0.216). Patients with larger tumors (RR = 2.071, P = 0.005) and those who received marginal excision (RR = 2.556, P = 0.005) had poor local recurrence-free survival. Besides, SYT-SSX1 (RR = 1.859, P = 0.037), older age (RR = 1.799, P = 0.040), and aggressive International Union Against Cancer stage (RR = 3.690, P < 0.001) proved to be adverse prognostic factors for metastasis-free survival. In conclusion, compared to SYT-SSX1, SYT-SSX2 was more frequent in Chinese patients with SS. Moreover, SYT-SSX1 was an adverse predictor for disease-specific survival and metastasis-free survival, but had no relation to local recurrence-free survival. In addition, histological grade and tumor size were also important prognostic factors for SS.

Synovial sarcoma of the kidney

The renal parenchyma is a rare site of origin for primary synovial sarcoma (SS). The present study describes the clinicopathologic, immunohistochemical, and molecular analysis of 7 cases of SS occurring in the kidney. There were 5 female and 2 male patients, with an age range of 15 to 46 years. They presented with solitary renal masses ranging in size from 10.0 cm to 17.0 cm in greatest dimension. Radical nephrectomy was performed in all cases. On gross examination, tumors were large, partially necrotic, and were seen to contain smooth-walled cysts in 4 cases. Histologically, the tumors were characterized by monomorphic spindle cells with indistinct cell borders arranged in intersecting nodular foci with hypocellular myxoid areas, together with a prominent hemangiopericytomatous pattern. The cysts were lined by hobnailed cells with eosinophilic cytoplasm. Immunohistochemically, BCL-2 was positive in all 6 cases in which it was performed, followed by vimentin (4/5 cases), MIC2 (CD99; 2/5 cases), calponin (2/2 cases), and epithelial membrane antigen (1/4 cases). Stains for cytokeratin and CD34 were consistently negative. Reverse transcription-polymerase chain reaction (RT-PCR) using RNA extracted from formalin-fixed paraffin-embedded tissues was carried out in 4 cases and SYT-SSX fusion gene transcript, which is the diagnostic hallmark of SS, was detected. Two patients developed pulmonary metastasis and died 6 and 12 months after diagnosis, respectively. This series of cases is distinct in terms of its morphological spectrum and confirmation by molecular technique.

A comparision of RT-PCR and FISH techniques in molecular diagnosis of Ewing's sarcoma in paraffin-embedded tissue

Ewing's sarcoma is relatively uncommon tumor representing 6-8 percent of malignant bone tumors with variable morphology. Cytogenetically, Ewing's sarcomas are characterized by a specific reciprocal chromosomal translocation t(11;22)(q24;q12). The presence of this chromosomal translocation has been detected in approximately 85 percent of the cases. The translocation results in the fusion of EWS gene from chromosome 22 to FLI1 gene at 11q24 which is a member of ETS family of transcription factors. In this study we performed a comparison of two molecular diagnostic strategies, namely RT-PCR and FISH, in fresh, frozen and formalin-fixed paraffin-embedded tissues. We conclude that FISH is a more sensitive technique than RT-PCR for the diagnosis of Ewing's tumors in formalin-fixed paraffin-embedded tissue. In conclusion, molecular pathology techniques, using reverse transcription-polymerase chain reaction (RT-PCR) and/or fluorescence in situ hybridization (FISH) are valuable diagnostic tools for evaluation of undifferentiated small round-cell tumors like Ewing's sarcoma.

Array painting reveals a high frequency of balanced translocations in breast cancer cell lines that break in cancer-relevant genes

Chromosome translocations in the common epithelial cancers are abundant, yet little is known about them. They have been thought to be almost all unbalanced and therefore dismissed as mostly mediating tumour suppressor loss. We present a comprehensive analysis by array painting of the chromosome translocations of breast cancer cell lines HCC1806, HCC1187 and ZR-75-30. In array painting, chromosomes are isolated by flow cytometry, amplified and hybridized to DNA microarrays. A total of 200 breakpoints were identified and all were mapped to 1 Mb resolution on bacterial artificial chromosome (BAC) arrays, then 40 selected breakpoints, including all balanced breakpoints, were further mapped on tiling-path BAC arrays or to around 2 kb resolution using oligonucleotide arrays. Many more of the translocations were balanced at 1 Mb resolution than expected, either reciprocal (eight in total) or balanced for at least one participating chromosome (19 paired breakpoints). Second, many of the breakpoints were at genes that are plausible targets of oncogenic translocation, including balanced breaks at CTCF, EP300/p300 and FOXP4. Two gene fusions were demonstrated, TAX1BP1-AHCY and RIF1-PKD1L1. Our results support the idea that chromosome rearrangements may play an important role in common epithelial cancers such as breast cancer.

[ATIC-ALK-positive anaplastic large cell lymphoma: a case report and review of the literature]

We report a 10-year-old girl with ATIC-anaplastic lymphoma kinase (ALK)-positive anaplastic large cell lymphoma (ALCL). She presented with inguinal, axillary, and paraaortic lymph node swellings that showed spontaneous regression over a 3-month period, followed by recurrence after an interval of 8 months. Radiological and clinical findings indicated Ann Arbor stage IIIA. Pathological findings showed that staining of ALK was restricted to the cytoplasm of ALCL cells. ATIC-ALK chimeric transcripts were detected by reverse transcriptase polymerase chain reaction. The patient was assigned to the standard risk group proposed by the international multicenter study for pediatric ALCL, ALCL99. The patient responded well to the treatment and remained in complete remission for more than 26 months. To date, 7 genes have been identified as a fusion partner of ALK, with the highest frequency in nucleophosmin (NPM). Little is known about the clinical implications of subtypes of ALCL harboring each of the 7 fusion genes, especially those of variant fusion genes other than NPM-ALK. In this paper, we review 9 patients with ATIC-ALK-positive ALCL in the literature in addition to discussing our patient. In eight of these 10 cases, disease occurred within the first three decades. Five of 6 cases that were followed continuously remained in complete remission.

Presentation of acute promyelocytic leukemia as granulocytic sarcoma

Granulocytic sarcoma (GS) is a localized tumor composed of immature myeloid cells. This extramedullary tumor can present before, concurrent with or after the diagnosis of acute myeloid leukemia. GS is extremely uncommon in acute promyelocytic leukemia (APL). As a proportion of patients never develop systemic disease, correct and timely diagnosis may be rather difficult, but is a prerequisite for optimal outcome. GS should be considered in the differential diagnosis of children with unusual bone lesions. We describe a patient with GS who presented with symptoms mimicking osteomyelytis or rheumatoid disease.

SK-NEP-1 and Rh1 are Ewing family tumor lines

The utility of preclinical models of childhood cancers is contingent upon reliably classifying them with their corresponding clinical counterparts. Molecular tools such as gene expression profiling allow researchers to confirm the similarity between clinical tumors and preclinical models. We describe the use of gene expression profiling to show that SK-NEP-1, a cell line previously thought to represent anaplastic Wilms tumor, is instead related to Ewing sarcoma. RT-PCR confirmed that SK-NEP-1 expresses EWS-FLI1 gene fusion transcripts characteristic of Ewing sarcoma, and DNA sequencing demonstrated the joining of exon 7 of EWS with exon 5 of FLI1 for these transcripts. Rh1, which was previously categorized as an alveolar rhabdomyosarcoma cell line, also has a gene expression profile suggestive of Ewing sarcoma and expresses EWS-FLI1 fusion transcripts in which exon 7 of EWS is joined with exon 6 of FLI1. These examples illustrate the importance of molecularly characterizing pediatric preclinical models used for testing new agents.

Primary synovial sarcoma of the kidney with rhabdoid features

Synovial sarcoma is a soft tissue sarcoma with clearly defined histologic, immunophenotypic, and molecular features. It occurs predominantly in the extremities of young adults but has been reported in many other anatomic sites. Histologically, it is classified as biphasic, monophasic, and poorly differentiated. The latter category, which includes tumors with a rhabdoid morphology, has been associated with a more aggressive behavior. Generally, the biphasic variant does not pose any diagnostic problem because of its typical histologic appearance; in contrast, the monophasic and poorly differentiated variants may represent a diagnostic challenge because their microscopic features can be confused with those of other spindle cell tumors with rhabdoid features. The application of molecular techniques, such as reverse transcriptase polymerase chain reaction to detect the fusion transcript associated with the characteristic t(X;18) translocation of synovial sarcoma, has enabled the confirmation of this diagnosis, even in cases of unusual localization, such as the one we present here.

A constitutively active SPTBN1-FLT3 fusion in atypical chronic myeloid leukemia is sensitive to tyrosine kinase inhibitors and immunotherapy

OBJECTIVES

To determine the consequences and significance of an acquired 46XX,t(2;13;2;21)(p13;q12;q33;q11.2) in atypical chronic myeloid leukemia (aCML).

METHODS

Translocation breakpoints were identified by fluorescence in situ hybridization and a novel fusion gene identified by rapid amplification of cDNA ends polymerase chain reaction. Functional analysis of the fusion was performed using the Ba/F3 transformation assay and specific inhibition demonstrated using small molecule inhibitors.

RESULTS

Fluorescence in situ hybridization indicated that FLT3 at 13q12 was disrupted and 5'-rapid amplification of cDNA ends polymerase chain reaction identified a novel in-frame mRNA fusion between exon 3 of SPTBN1 (spectrin, beta, nonerythrocytic 1) at chromosome 2p16 and exon 13 of FLT3. Expression of SPTBN1-FLT3 transformed Ba/F3 cells to growth factor independence and was accompanied by constitutive phosphorylation of the fusion protein and the downstream substrate extracellular signal-regulated kinase 1/2. The growth of transformed cells was inhibited in a dose-dependent fashion by SU11657, PKC412, and TKI258 (CHIR-258), but not by imatinib. To determine if FLT3 might be involved more widely in BCR-ABL-negative aCML, we analyzed 40 cases and found two were internal tandem duplication-positive, but D835 mutations were not observed. The t(2;13;2;21) patient was initially treated with hydroxyurea and subsequently underwent an unrelated donor bone marrow transplantation. She relapsed cytogenetically at 4 years, but responded to donor lymphocyte infusion, achieving sustained cytogenetic and molecular (nested reverse transcription polymerase chain reaction) remission.

CONCLUSION

Although FLT3 abnormalities are uncommon in aCML, SPTBN1-FLT3 is a novel constitutively active tyrosine kinase that appears to responsive to both targeted signal transduction therapy and immunotherapy.

The severity of FIP1L1–PDGFRA-positive chronic eosinophilic leukaemia is associated with polymorphic variation at the IL5RA locus

We have investigated the hypothesis that constitutional genetic variation in IL-5 signalling may be associated with the development or severity of FIP1L1-PDGFRA-positive chronic eosinophilic leukaemia (CEL) in humans. We genotyped six single-nucleotide polymorphisms (SNP) within or close to the IL5RA or IL5 genes in 82 patients with FIP1L1-PDGFRA-positive CEL plus, as controls, healthy individuals (n=100), patients with FIP1L1-PDGFRA-negative eosinophilia (n=100) or patients with chronic myeloid leukaemia (CML) (n=100). We found no association between SNP allele frequency between FIP1L1-PDGFRA-positive and control cases. However, for FIP1L1-PDGFRA cases, we found an association between the genotype at rs4054760, an SNP in the 5'-UTR of IL5RA and peripheral blood eosinophil count (P=0.026) as well as the presence or absence of tissue infiltration (P=0.032). Although these associations fell below the level of significance once corrected for multiple testing, no such association was seen in FIP1L1-PDGFRA-negative cases and no difference in allele frequencies for rs4054760 was seen in control populations across Europe. Furthermore, in an analysis of 112 patients with CML, IL5RA expression was strongly related to rs4054760 genotype (P<0.001). These data suggest that the variations in IL5RA expression are linked to constitutional IL5RA genotype and severity of FIP1L1-PDGFRA disease.

Microfluidic chips for detecting the t(4;14) translocation and monitoring disease during treatment using reverse transcriptase-polymerase chain reaction analysis of IgH-MMSET hybrid transcripts

Diagnosis platforms incorporating low-cost microfluidic chips enable sensitive, rapid, and accurate genetic analysis that could facilitate customized therapies tailored to match the vulnerabilities of any types of cancer. Using ex vivo cancer cells, we have detected the unique molecular signature and a chromosomal translocation in multiple myeloma. Multiple myeloma is characterized by IgH rearrangements and translocations that enable unequivocal identification of malignant cells, detected here with integrated microfluidic chips incorporating genetic amplification via reverse transcriptase-polymerase chain reaction and capillary electrophoresis. On microfluidic chips, we demonstrated accurate and versatile detection of molecular signatures in individual cancer cells, with value for monitoring response to therapy, detecting residual cancer cells that mediate relapse, and evaluating prognosis. Thus, testing for two clinically important molecular biomarkers, the IgH VDJ signature and hybrid transcripts signaling the t(4;14) chro-mosomal translocation, with predictive value in diagnosis, treatment decisions, and monitoring has been efficiently implemented on a miniaturized microfluidic system.

[Combined application of multiplex reverse transcription-polymerase chain reaction and karyotype analysis to detection of clonal chromosomal aberrations in acute myeloid leukemia]

BACKGROUND & OBJECTIVE

Cytogenetic analysis plays a critical role in the diagnosis and prognosis evaluation of leukemia, but karyotype analysis is time-consuming and difficult to yield sufficient metaphases; while polymerase chain reaction (PCR) is sensitive and efficient. This study was to investigate combined application of multiplex reverse transcription-polymerase chain reaction (RT-PCR) and karyotype analysis to the detection of clonal chromosomal aberrations in acute myeloid leukemia (AML), and explore the expression and distribution of fusion genes among the subtypes of AML.

METHODS

Sixty AML patients were examined by multiplex RT-PCR. Cytogenetic data were obtained from 37 of them by R or G banding techniques.

RESULTS

Fusion genes, including AML1/ETO, PML/RARalpha, CBFbeta/MYH11, MLL gene rearrangements (that is, MLL/AF6, MLL/AF9, MLL/AF10, and MLL/MLL), DEK/CAN, TEL/PDGFR, and AML1/MDS1 (EVI-1), were detected in 28 (46.7%) patients by multiplex RT-PCR. In the 37 patients who received karyotype analysis, data were available in 30 patients and cytogenetic aberrations were detected in only 14 (46.7%) of them. The detection rate of clonal chromosomal aberrations was enhanced to 59.5% by combined application of multiplex RT-PCR and karyotype analysis.

CONCLUSION

Multiplex RT-PCR combined with karyotype analysis can improve the detection rate of clonal chromosomal aberrations in AML.

Renal Cell Carcinoma Associated with TFE3 Gene Fusion in an Elderly Woman

We present a case report of a renal cell carcinoma with TFE3 overexpression (related to TFE3 gene fusion) in a 63-year-old woman. Such tumors have been reported predominantly in children and young adults, and to our knowledge there are only 2 such cases mentioned in the literature in patients older than ours. However, we believe that this tumor may be underdiagnosed in adults owing to its similarity to clear cell (conventional) carcinoma and in some cases to papillary renal carcinoma.