Evaluation of MYC status in oral lichen planus in patients with progression to oral squamous cell carcinoma.

BACKGROUND: Malignant transformation of oral lichen planus (OLP) to oral squamous cell carcinoma (OSCC) is controversial. C-MYC is a proto-oncogene involved in various solid tumours, including OSCC. OBJECTIVES: To determine MYC status using fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC) in OLP lesions from 10 patients with progression to OSCC (group I) and to compare this with OLP lesions from patients without progression to OSCC (group II). METHODS: We constructed two tissue microarrays with 11 OSCC samples (group IA), 17 OLP samples from the same patients (group IB) and 13 OLP specimens from 12 control patients (group II). FISH evaluation of the MYC gains was determined in 100 nonoverlapping nuclei per sample. IHC evaluation was determined by calculating the percentage C-MYC expression in the epithelial cells. RESULTS: OSCC samples showed MYC copy number gains and C-MYC overexpression in 91% and 73% of cases, respectively. MYC gains were detected in 47% of samples from group IB and were absent from all samples from group II. C-MYC was overexpressed in 87% of cases from group IB and in only 44% of control specimens (group II). The differences in MYC status between groups IB and II were statistically significant. CONCLUSIONS: OLP lesions in patients with progression to OSCC show MYC gains and C-MYC overexpression. In patients with severe OLP, determining MYC status may predict a subgroup of subjects with a higher risk of progression to OSCC.

Multiple genetic copy number alterations in oral squamous cell carcinoma: study of MYC, TP53, CCDN1, EGFR and ERBB2 status in primary and metastatic tumours.

BACKGROUND: Oncogenesis in the oral cavity is believed to result from genetic alterations that cause a stepwise transformation of the mucosa to invasive carcinoma. In oral squamous cell carcinoma (OSCC) multiple cytogenetic abnormalities have been reported, but their practical significance remains uncertain. OBJECTIVE: To evaluate the usefulness of the assessment of CCND1, MYC, EGFR, ERBB2 and TP53 in OSCC and lymph node metastases. METHODS: Fifty-one consecutive samples of OSCC, nine lymph node biopsies showing metastatic spread from OSCC, 16 biopsies diagnosed as oral leucoplakia (OLK), 13 samples corresponding to oral lichen planus (OLP) and 14 samples from normal oral mucosa were included in the study. Clinical and histopathological characteristics were reviewed. The genetic and protein status of the CCND1, MYC, EGFR, ERBB2 oncogenes and the TP53 tumour suppressor gene were assessed by fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC). The obtained results were compared with the clinical characteristics and the outcome of the OSCCs. RESULTS: TP53 gene losses and MYC, ERBB2, CCND1 and EGFR copy number gains and amplifications were detected in a higher proportion in OSCC and lymph node samples than in OLK and OLP samples (P < 0·005). Overexpression of p53, Myc, Cyclin D1, c-erbB-2 and epidermal growth factor receptor (EGFR) was more prevalent in malignant samples than benign samples (P < 0·05). Correlation between FISH and IHC results was demonstrated in MYC, EGFR and CCND1 studies. The presence of two or more genetic abnormalities in the studied loci was exclusively detected in primary and metastatic OSCC. CONCLUSIONS: In our series, genetic abnormalities in TP53, MYC, CCND1, ERBB2 and EGFR detected by FISH were absent in inflammatory lesions, infrequent in precursor lesions and common in tumoral lesions. Evaluation of the genetic status of TP53, MYC, CCND1, ERBB2 and EGFR may be an additional diagnostic tool in distinguishing benign from malignant oral lesions in histopathologically challenging cases.

MYC gene numerical aberrations in actinic keratosis and cutaneous squamous cell carcinoma.

BACKGROUND: The genetic alterations that drive the transition from actinic keratoses (AKs) to cutaneous squamous cell carcinomas (SCCs) have not been defined precisely. Amplification and/or overexpression of the MYC proto-oncogene have been demonstrated in several human, malignant tumours including head and neck SCCs. OBJECTIVES: To evaluate the presence of MYC genomic aberrations in both AKs and SCCs. METHODS: Skin biopsy specimens corresponding to AKs, SCCs and control samples were included in two paraffin-embedded tissue microarrays. MYC cytogenetic profile was evaluated by fluorescence in situ hybridization (FISH). The results obtained were compared with MYC immunohistochemical expression. RESULTS: Twenty-three AKs and 30 SCCs were evaluated. MYC numerical aberrations were observed in eight of 23 (35%) AKs and 19 of 30 (63%) SCCs (P = 0.05). MYC numerical aberrations were more frequent in moderately to poorly differentiated SCCs (77%) when compared with well-differentiated SCCs (25%; P = 0.027). A significant association between copy number gains of MYC by FISH analysis and MYC protein expression was demonstrated. CONCLUSIONS: MYC gains and amplifications are frequent cytogenetic abnormalities in SCCs and may play a relevant role in promoting SCC undifferentiation and tumoral progression.

European recommendations and quality assurance for cytogenomic analysis of haematological neoplasms.

Cytogenomic investigations of haematological neoplasms, including chromosome banding analysis, fluorescence in situ hybridisation (FISH) and microarray analyses have become increasingly important in the clinical management of patients with haematological neoplasms. The widespread implementation of these techniques in genetic diagnostics has highlighted the need for guidance on the essential criteria to follow when providing cytogenomic testing, regardless of choice of methodology. These recommendations provide an updated, practical and easily available document that will assist laboratories in the choice of testing and methodology enabling them to operate within acceptable standards and maintain a quality service.

Primitive neuroectodermal tumor of the central nervous system with glial differentiation: a FISH study of an adult case.

Primitive neuroectodermal tumors (PNETs) of the central nervous system (CNS), a rare occurrence in adults, may show glial differentiation and can be misinterpreted as pure astrocytic neoplasms. Few fluorescence in situ hybridization (FISH) studies have been carried out on these tumors; isochromosome 17q was found to be the major chromosomal abnormality. We present the case of an adult in which we performed a FISH study of both the glial and neuronal components. A complex array of FISH changes, not including an isochromosome 17q were identified.

A new case of Turner syndrome associated with multiple myeloma.

A 62-year-old woman with phenotypic stigmata of Turner syndrome and a mosaic cytogenetic pattern, 45,X/45,XX, developed multiple myeloma. The affected cells had a number of karyotypic changes in addition to the loss of the X chromosome.

New t(11;12)(q12;q11) characterized by RxFISH in a patient with T-cell large granular lymphocyte leukemia.

Chromosomal abnormalities in patients with large granular lymphocyte leukemia (LGLL) are rare. Herein we present a novel cytogenetic abnormality t(11;12)(q12;q11) in a patient with LGLL identified by cross-species color banding (RxFISH). The application of RxFISH allowed the rapid and easy identification of a chromosome rearrangement that was not recognized by conventional cytogenetics. Therefore, RxFISH is a suitable complement to, but not a replacement for, conventional cytogenetics.

Two new cases of near-tetraploidy in adult acute myeloid leukemia.

Tetraploid or near-tetraploid karyotype has been described rarely in hematologic neoplasms. Herein we report two new cases of adult acute myeloblastic leukemia, M0 and M1 FAB subtypes that showed near-tetraploid clones that were studied with conventional cytogenetics and in situ hybridization (ISH). We compare our new cases with those previously reported.

Cytogenetic and fluorescence in situ hybridization studies in four cases of plasma cell leukemia.

We present a cytogenetic and fluorescence in situ hybridization (FISH) study, using centromeric probes for chromosomes 3, 7, 11, and 18, TP53 gene (17p13), and RB-1 locus (13q14) DNA probes, in four cases of plasma cell leukemia (PCL). Among the four cases, three presented monosomy of the RB-1 locus and one monoallelic deletion of the TP53 gene. The present report shows the usefulness of the FISH technique to detect abnormalities not previously observed by conventional cytogenetics.

Dicentric (17;18) in a case of atypical B-cell chronic lymphocytic leukemia.

We report a new dic(17;18)(p11.2;p11.2) in a 61-year-old male patient diagnosed with atypical B-cell chronic lymphocytic leukemia. The dic(17;18)(p11.2;p11.2) was detected in 90%, 10%, and 100% of metaphases in the peripheral blood, bone marrow, and lymph node, respectively. Fluorescence in situ hybridization studies with chromosome 17 and 18 centromeric probes revealed the presence of two normal centromeres of both chromosomes 17 and 18. The centromere of one chromosome 17 was found together with the centromere of one chromosome 18, confirming the dicentric nature of the rearrangement. In addition, with the use of a 17p13.1 region probe, monosomy of the 17p13 region, where the Tp53 gene is located, was observed.

Cytogenetic abnormalities in three patients with B-cell prolymphocytic leukemia.

We present the cytological features, conventional cytogenetics, and in situ hybridization (ISH) findings of three cases of B-cell prolymphocytic leukemia (B-PLL). The diagnosis was made according to the French-American-British (FAB) criteria. We considered a diagnosis of B-PLL when a predominance (> 50%) of lymphoid cells with coarse chromatin but prominent central nucleoli and more abundant cytoplasm than typical chronic lymphocytic leukemia (CLL) cells were present. B-PLL express strong SIg, B-cell antigens, and reactivity with the monoclonal antibody FMC7. Chromosome analysis was carried out on lymphoid cells from peripheral blood and, in one patient, from lymph node. The phytohemagglutinin (PHA) mitogen was used. ISH was performed with two types of probes: the biotin-labeled chromosome 12-specific alpha satellite DNA probe to detect trisomy 12, and biotin-labeled libraries of whole chromosomes 1, 7, and 14. Clonal chromosome abnormalities were found in all three patients; in one, a complex karyotype was observed. The most frequent recurrent abnormality was trisomy 12. Our results suggest that PLL usually presents with cytogenetic abnormalities. The finding of translocation (11;14) is noteworthy; chromosomes 1 and 3 are also involved.

Coexistence of tetrasomy 8 and trisomy 8 in a case with myeloid metaplasia with myelofibrosis.

We present a case of myeloid metaplasia with myelofibrosis (MM/MF), with tetrasomy 8 as the sole cytogenetic abnormality detected by conventional cytogenetic studies. Tetrasomy 8 was also detected by in situ interphase studies and confirmed by chromosome painting in metaphase. To our knowledge, this is the first case of MM/MF with tetrasomy 8. Noteworthy is the association with neurofibromatosis.

Cytogenetic findings in five patients with hairy cell leukemia.

We studied five cases of hairy cell leukemia (HCL) using conventional cytogenetics. All patients were diagnosed with typical HCL. Chromosome analysis was carried out on a 72-hour culture of peripheral blood. Phytohemagglutinin (PHA) mitogen was used. Clonal chromosome abnormalities were found in 2/5 patients (40%), a complex abnormality being identified in one of them. The chromosomes involved were: 1, 6, 7, 8, and 17. No patient showed trisomy 12 or a 14q+. An interesting result was the finding of del(7)(q32) as a sole anomaly.

Translocation (11;14)(q13;q32) and preferential involvement of chromosomes 1, 2, 9, 13, and 17 in mantle cell lymphoma.

We have studied 13 cases of histologically confirmed mantle cell lymphomas (MCL) combining cytological-immunological features with conventional cytogenetics and in situ hybridization (ISH) techniques. Peripheral blood smears and lymph node biopsies expressed the typical mantle zone pattern with alpha B-cell phenotype. Most of the cases (11 of 13) had lymphomatous cells in the peripheral blood. Chromosome analysis was carried out on lymphoid cells from peripheral blood and/or lymph node biopsies. Phytohemagglutinin (PHA) and phorbol 12-myristate 13 acetate (TPA) were used as mitogens. Biotin-labeled libraries of whole chromosomes implicated in complex karyotypes were used to improve their interpretation. Clonal chromosome abnormalities were found in 10 of 13 patients (77%); 7 of these had a complex abnormality. The most frequent recurrent structural abnormalities were: t(11;14)(q13;q32), involvement of chromosome 1 (der[1], del[1], dup[1]), chromosome 2 (del[2], der[2]), chromosome 9 (der[9], -9), chromosome 13 (add[13], t[13q]), and chromosome 17 (add[17], der[17], t[17q]). The most frequent numerical abnormalities were monosomy 21 and loss of the Y chromosome.

Molecular characterization and clinical impact of TMPRSS2-ERG rearrangement on prostate cancer: comparison between FISH and RT-PCR.

Prostate cancer (PCa) is a very heterogeneous disease, and there are constraints in its current diagnosis. Serum PSA levels, digital rectal examination (DRE), and histopathologic analysis often drive to overdiagnosis and overtreatment. Since 2005, the presence of the genetic rearrangement between transmembrane-serine protease gene (TMPRSS2) and the erythroblast transformation-specific (ETS) member ERG (v-ets erythroblastosis virus E26 oncogene homolog avian) has been demonstrated in almost half of PCa cases. Both FISH and RT-PCR are useful tools for detecting these rearrangements, but very few comparatives between both techniques have been published. In this study, we included FFPE tumors from 294 PCa patients treated with radical prostatectomy with more than 5 years of followup. We constructed a total of 20 tissue microarrays in order to perform break-apart and tricolor probe FISH approaches that were compared with RT-PCR, showing a concordance of 80.6% (P < 0.001). The presence of TMPRSS2-ERG rearrangement was observed in 56.6% of cases. No association between TMPRSS2-ERG status and clinicopathological parameters nor biochemical progression and clinical progression free survival was found. In conclusion, this study demonstrates that both FISH and RT-PCR are useful tools in the assessment of the TMPRSS2-ERG fusion gene status in PCa patients and that this genetic feature per se lacks prognostic value.

Impact of adjunct cytogenetic abnormalities for prognostic stratification in patients with myelodysplastic syndrome and deletion 5q.

This cooperative study assessed prognostic factors for overall survival (OS) and risk of transformation to acute myeloid leukemia (AML) in 541 patients with de novo myelodysplastic syndrome (MDS) and deletion 5q. Additional chromosomal abnormalities were strongly related to different patients' characteristics. In multivariate analysis, the most important predictors of both OS and AML transformation risk were number of chromosomal abnormalities (P<0.001 for both outcomes), platelet count (P<0.001 and P=0.001, respectively) and proportion of bone marrow blasts (P<0.001 and P=0.016, respectively). The number of chromosomal abnormalities defined three risk categories for AML transformation (del(5q), del(5q)+1 and del(5q)+ ≥ 2 abnormalities) and two for OS (one group: del(5q) and del(5q)+1; and del(5q)+ ≥ 2 abnormalities, as the other one); with a median survival time of 58.0 and 6.8 months, respectively. Platelet count (P=0.001) and age (P=0.034) predicted OS in patients with '5q-syndrome'. This study demonstrates the importance of additional chromosomal abnormalities in MDS patients with deletion 5q, challenges the current '5q-syndrome' definition and constitutes a useful reference series to properly analyze the results of clinical trials in these patients.