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1/11. Two case studies of chronic idiopathic neutropenia preceding acute myeloid leukaemia.

    Chronic idiopathic neutropenia is regarded as a benign disorder without risk of malignant transformation. We present two patients with chronic idiopathic neutropenia who showed disease progression to acute myeloid leukaemia. sequence analysis of the granulocyte-colony stimulating factor receptor (G-CSFR) gene from leukaemic DNA did not reveal any mutations and microsatellite analysis provided no evidence of microsatellite instability or loss of constitutional heterozygosity. These case studies suggest that chronic idiopathic neutropenia may constitute a preleukaemic condition in some patients. Alterations of the G-CSFR or defective dna mismatch repair do not appear to be involved in malignant transformation.
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ranking = 1
keywords = microsatellite instability, microsatellite, instability
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2/11. choriocarcinoma and partial hydatidiform moles.

    BACKGROUND: Partial hydatidiform moles (PMs) rarely require chemotherapy and have never previously been proven to transform into choriocarcinoma, the most malignant form of gestational trophoblastic disease (GTD). Consequently, some have questioned whether women with PMs need human chorionic gonadotropin (hCG) follow-up. Here, we investigate whether PMs can transform into choriocarcinomas. methods: patients with a PM who developed a subsequent choriocarcinoma were identified from our GTD database. The histology of both PM and ensuing choriocarcinoma was reviewed and flow cytometry used to verify the triploid status of the PMs. To determine whether the choriocarcinoma arose from the PM, DNA from the PM and choriocarcinoma in each patient was compared using microsatellite polymorphisms. FINDINGS: Of the 3000 patients with PM, 15 required chemotherapy for persisting GTD. This was identified as choriocarcinoma in three cases. In one patient, the local pathologist could not differentiate between a PM or a hydropic abortion and neither central histological review nor hCG follow-up were obtained. This patient nearly died before the diagnosis of choriocarcinoma was made. Fortunately, the local pathologists correctly diagnosed PM in the two other patients who were then registered for hCG follow-up. Some months later, the hCG was rising and repeat uterine evacuation revealed choriocarcinoma. The PM was confirmed to be triploid in all three cases and genetic analysis showed that the subsequent choriocarcinomas contained identical single maternal and two paternal alleles at several independent loci. INTERPRETATION: Our results show that PMs can transform into choriocarcinoma. All patients with suspected PM should be reviewed centrally and, if confirmed, need hCG follow-up.
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ranking = 0.060005807488745
keywords = microsatellite
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3/11. microsatellite instability in gonadal tumors of XY pure gonadal dysgenesis patients.

    To investigate genetic alternation accompanied by malignant transformation in gonadal tumors of XY pure gonadal dysgenesis patients, we investigated microsatellite instability in the hMSH1, hMSH2, TP53, and DCC loci, and ras mutations in two patients. The gonadal tumors from the patients were combined gonadoblastoma and dysgerminoma. microsatellite instability and/or loss of heterozygotes (LOH) at hMSH1, hMSH2, and TP53 were detected in the dysgerminoma lesions of the both patients, but were not observed in any normal tissues. In the analyses of the H-, K-, or N-ras genes, where specific mutations have been frequently reported, no mutations were observed in the tumors. It is suggested therefore that microsatellite instability plays an important role in malignant transformation of gonadal tumors in patients with XY pure gonadal dysgenesis.
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ranking = 1.8876760661022
keywords = microsatellite instability, microsatellite, instability
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4/11. Anaplastic thyroid cancer evolved from papillary carcinoma: demonstration of anaplastic transformation by means of the inter-simple sequence repeat polymerase chain reaction.

    BACKGROUND: In thyroid tumors, the coexistence of well- and poorly differentiated tumor types has led to the hypothesis that poorly differentiated thyroid tumors develop from well-differentiated thyroid tumors. By evaluating the genomic instability of histologically distinct but coexisting tumor foci, this study aimed to develop an improved understanding of thyroid tumorigenesis and tumor evolution. DESIGN: laser capture microdissection (LCM) was carried out on archival formalin-fixed, paraffin-embedded sections from a tumor containing foci of classic papillary thyroid cancer and anaplastic thyroid cancer. DNA was extracted from each microdissected tumor focus. In addition, cryopreserved bulk normal and neoplastic thyroid tissue underwent DNA extraction. All DNA samples were subsequently evaluated for genomic instability by means of inter-simple sequence repeat polymerase chain reaction. RESULTS: The LCM DNA from each archival paraffin-embedded tumor focus demonstrated unique patterns of banding as compared with the cryopreserved tumor and normal tissue DNA. Thus, intratumoral variability in genomic instability was observed. Comparison of inter-simple sequence repeat polymerase chain reaction patterns of LCM DNA from adjacent foci of papillary and anaplastic tumors showed conserved genome alterations. CONCLUSIONS: At the genome level, thyroid tumors may be highly heterogeneous. The intratumoral histologic heterogeneity observed in thyroid neoplasms reflects genetically heterogeneous underlying tumor cell populations that are demonstrated by the observed differences in their rates and extents of genomic instability. The conserved genomic alterations in the microdissected papillary and anaplastic foci suggest intratumoral evolution, with transformation of a preexisting papillary tumor to anaplastic carcinoma.
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ranking = 0.0061501448637306
keywords = instability
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5/11. Cronkhite-canada syndrome containing colon cancer and serrated adenoma lesions.

    We describe a case of Cronkhite-canada syndrome associated with sigmoid colon cancer, and provide a literature review. A 77-year-old man was diagnosed with sigmoid colon cancer after presenting with hypoproteinemia, nail atrophy, loss of scalp hair, hyperpigmentation, and gastrointestinal polyposis. The findings were consistent with Cronkhite-canada syndrome. The colon polyps were histologically serrated adenomas, whose crypts showed a saw-toothed growth pattern with dysplasia, or tubular adenoma. Cronkhite-canada syndrome associated with colon cancer has been reported in 31 cases. The availability of histologic material permitted reexamination of 25 of these cases. Serrated adenoma of the polypoid lesions was retrospectively found in 10 (40%) of the 25 cases. By comparison, the incidence of serrated adenomas has been estimated to occur in about 1% of all general polyps. Taken together, it is suggested that Cronkhite-canada syndrome associated with colorectal cancer frequently has polyps containing serrated adenoma lesions. In the case described here, microsatellite instability and overexpression of the p53 protein were found in the cancer lesion and serrated adenoma lesions, and none of the lesions showed a loss of heterozygosity of various genes or K-RAS mutations. Thus, genetic alterations between the serrated adenoma and the colorectal cancer was correlated in this case. These findings suggested the possibility of a serrated adenoma-carcinoma sequence in this case of Cronkhite-canada syndrome.
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ranking = 0.93999419251126
keywords = microsatellite instability, microsatellite, instability
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6/11. Genomic imbalance and onco-protein expression of ovarian endometrioid adenocarcinoma arisen in an endometriotic cyst.

    BACKGROUND: Malignant transformation in endometriosis is a rare but well known complication. However, detailed mechanisms of malignant transition and tumourigenesis in endometriosis remain unknown. We here describe the case of an endometrioid carcinoma arisen in endometriotic ovarian cyst fulfilling Sampson's criteria for malignant transformation of endometriosis. We compared genetic alterations and oncoprotein expression in the endometriotic ovarian cyst and the associated endometrioid adenocarcinoma. MATERIALS AND methods: genomic instability was evaluated by comparative genomic hybridization (CGH). Onco-protein expression was analysed by immunohistochemistry with antibodies against bcl-2, c-MYC, cyclin d1, p53, HER-2 and KIT protein. RESULTS: CGH revealed a gain of 8q, including the locus of the oncogene c-MYC at 8q24. immunohistochemistry disclosed a differing protein expression profile between the epithelia of the pre-existing cyst and adenocarcinoma. Apart from HER-2, all onco-proteins were more strongly expressed in epithelial cells of the adenocarcinoma than of the endometriotic cyst. CONCLUSION: The solitary genomic imbalance of chromosome 8 possibly reflects the importance for initiation and/or progression of endometrioid carcinoma. Overexpression of onco-proteins then may occur subsequently in the malignant transformation of ovarian endometriosis. However, the exact mechanisms of malignant transition in ovarian endometriosis remain to be elucidated in future studies with a higher number of cases.
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ranking = 0.0015375362159327
keywords = instability
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7/11. Malignant transformation of atypical endometrial hyperplasia after progesterone therapy showing germ-cell tumor-like differentiation.

    A 31-year-old woman was treated for atypical endometrial hyperplasia (AEH) with high-dose medroxyprogesterone acetate (MPA) therapy to preserve fertility. The AEH was found by repeated cytologic and histologic examinations to have completely disappeared with the therapy, but 3 years after her last follow up she required emergency surgery to treat severe genital bleeding. The hysterectomied uterus consisted mostly of poorly differentiated adenocarcinoma, G3 endometrioid type. Minor AEH was present in the exophytic area, in which some glands were cystically dilated. Part of the AEH had transformed into other histologic features with germ-cell-like differentiation, demonstrated by immunohistochemical positive reaction of placental alkaline phosphatase, alpha-fetoprotein, and human chorionic gonadotrophin. Recurrent AEH had undergone malignant transformation, resulting in the development of well- and poorly differentiated adenocarcinoma and tumor exhibiting germ-cell-like differentiation. The patient died of a massive tumor extension 7 months after surgery. The AEH before MPA therapy and the recurrent tumors had genetically different characteristics based on evidence of a loss of heterozygosity, detected at D8S1132 (chromosomal locus, 8q22.1) in the latter but not in the former, by analysis of genetic alterations using microsatellite markers.
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ranking = 0.060005807488745
keywords = microsatellite
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8/11. Chromosomal transformation in donor cells following allogeneic bone marrow transplantation.

    We report here a monosomy 7 transformation of donor cells following matched-unrelated, same sex, allogeneic bone marrow transplantation in a patient with severe congenital aplastic anemia. A PCR technique was employed to amplify microsatellite markers on chromosome 7 to confirm donor/recipient identity. We found that the transformation of monosomy 7 occurred in previously genetically normal donor cells. This study suggests that the microenvironment of the bone marrow of our patient with severe congenital aplastic anemia may have played a critical role in the development of monosomy 7 of normal donor cells and we conclude that chromosomal microsatellite marker analysis can be a valuable tool for precise donor/recipient differentiation in engraftment monitoring.
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ranking = 0.12001161497749
keywords = microsatellite
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9/11. Distribution of aneuploid cell populations in ulcerative colitis with dysplasia or cancer.

    flow cytometry was used to detect the presence and assess the distribution of aneuploid cell populations in eight proctocolectomy specimens from patients with ulcerative colitis. Mucosal samples were taken according to a systematic protocol for flow cytometry, the surrounding tissue was examined histologically, and the distributions of flow cytometric and histologic abnormalities were "mapped" within each resected colon. Two resection specimens that were negative for dysplasia lacked aneuploid cell populations. Four resection specimens with final case diagnoses of dysplasia or Dukes' stage A carcinoma had 1-5 regions of aneuploidy or increased 4N (G2/tetraploid) cell populations located in discrete areas of the colon. Two specimens with dysplasia or Dukes' stage C carcinoma each had 14-15 different, often overlapping, regions of aneuploidy or increased 4N (G2/tetraploid) cell populations involving large portions of the colonic mucosa. Analysis of the DNA content of the invasive portion of the tumor from the specimen with a Dukes' stage C carcinoma showed a single aneuploid cell population. The results show that single or multiple aneuploid cell populations are often present in colons resected for ulcerative colitis with dysplasia or early cancer. The distribution of these aneuploid cell populations suggests that each represents a clone of cells that has expanded to occupy a discrete region of colonic mucosa. Additional genetic errors may result in multiple aneuploid cell populations that may be associated with an increased risk of developing cancer. These data, therefore, are consistent with the hypothesis that genomic instability and clonal evolution are associated with the progression to dysplasia and carcinoma in ulcerative colitis. Because flow cytometry can measure aneuploid cell populations in colonoscopic mucosal biopsies, it may prove to be complementary to histology for detecting patients with ulcerative colitis who are at risk for neoplastic progression.
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ranking = 0.0015375362159327
keywords = instability
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10/11. A trichilemmal carcinoma arising from a proliferating trichilemmal cyst: the loss of the wild-type p53 is a critical event in malignant transformation.

    The genetic events responsible for tumor progression may be defined by careful analysis of genetic changes in well-chosen tumors which contain distinct cell populations representing each stage of progression. Here we report a case of a trichilemmal carcinoma arising in the wall of a proliferating trichilemmal cyst (PTC). DNA was isolated from microdissected areas of the PTC and the carcinoma respectively, and PCR-based microsatellite loss of heterozygosity (LOH) analysis as well as p53 gene sequencing performed. A CGA to TGA nonsense mutation at codon 306 in exon 8 of the p53 gene was found in both samples. LOH analysis showed that the PTC retained chromosome arm 17p (where the p53 gene resides), whereas the carcinoma was associated with the loss of this allele. All the other loci examined were retained including 3p, 9q, 13q and 17q in both tumor parts. The results confirm a common clonal origin of the PTC and the trichilemmal carcinoma, and strongly suggest that the complete loss of the wild-type p53 is a critical event responsible for malignant transformation in this particular case.
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ranking = 0.060005807488745
keywords = microsatellite
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