The molecular spectrum and clinical impact of DIS3 mutations in multiple myeloma.

Multiple myeloma (MM) is a plasma cell neoplasm that presents with a major biological and clinical heterogeneity. We here investigated the spectrum of clonal and subclonal mutations of DIS3, an active part of the exosome complex, that may play a role in the development or progression of MM. The whole coding sequence of DIS3 was subjected to deep sequencing in 81 uniformly-treated MM patients and 12 MM cell lines and the overall occurrence of DIS3 mutations as well as the presence of DIS3 mutations in minor and major subclones were correlated with cytogenetic alterations and clinical parameters. Our study identified DIS3 mutations in 9/81 patients that were associated with 13q14 deletions and IGH translocations on the cytogenetic level. Specifically, we detected seven novel somatic DIS3 single nucleotide variants (SNVs) and defined three hot spot mutations within the RNB domain. Lastly, we found a trend towards a shorter median overall survival for patients with DIS3 mutations, and patients carrying DIS3 mutations in minor subclones of their tumours showed a significantly worse response to therapy compared to patients with DIS3 mutations in the major subclone.

Primary cutaneous marginal zone lymphomas with plasmacytic differentiation show frequent IgG4 expression.

The expression of IgG4 in malignant B-cell lymphomas has only partially been studied. Recent reports described single cases of marginal zone lymphomas arising in the ocular adnexae that express IgG4. Moreover, a subset of dura-associated marginal zone lymphomas appear to express IgG4 as well. We investigated IgG4 expression in a more systematic manner in a large cohort of marginal zone lymphoma specimens derived from the archive of our institute. Overall, we examined 169 marginal zone lymphomas of various primary sites that displayed a distinct plasmacytic differentiation and light chain restriction, allowing for a detailed investigation of the immunoglobulin heavy chain expression in these tumors by immunohistochemistry. Unexpectedly, primary cutaneous marginal zone lymphomas showed frequent IgG4 expression. Although only 1 out of 120 noncutaneous marginal zone lymphomas, located in the ocular adnexae, expressed IgG4, 19 of 49 (39%) primary cutaneous marginal zone lymphomas showed this feature, constituting the highest expression rate of IgG4 reported to date in any B-cell lymphoma. None of the IgG4-positive cutaneous marginal zone lymphomas with available clinical data showed evidence of a preexisting systemic IgG4-related disease, suggesting a localized immunologic IgG4-driven pathogenetic process at early stages of the disease. IgG4-positive and IgG4-negative primary cutaneous marginal zone lymphomas did not significantly differ in architectural features of the infiltrate or the composition of the reactive T-cell infiltrate as determined by analysis of T-cell content, CD4/CD8 ratio, and content of FOXP3- and PD1-positive T cells. Although the pathogenetic role of IgG4 expression in a significant subset of primary cutaneous marginal zone lymphomas with plasmacytic differentiation remains unclear at present, the demonstration of IgG4 expression in a marginal zone lymphoma involving the skin might be a helpful clue in the routine diagnostic setting, as these tumors will almost invariably be of primary cutaneous origin with an extremely low risk of spread to noncutaneous sites and an excellent prognosis.

MicroRNA profiles of t(14;18)-negative follicular lymphoma support a late germinal center B-cell phenotype.

A total of 90% of follicular lymphomas (FLs) harbor the translocation t(14;18) leading to deregulated BCL2 expression. Conversely, 10% of FLs lack the t(14;18), and the majority of these FLs do not express BCL2. The molecular features of t(14;18)-negative FLs remain largely unknown. We performed microRNA expression analysis in 32 FL grades 1 to 3A, including 17 t(14;18)-positive FLs, 9 t(14;18)-negative FLs without BCL2 expression, and 6 t(14;18)-negative FLs with BCL2 expression. MicroRNA profiles were correlated with corresponding mRNA expression patterns, and potential targets were investigated by quantitative PCR and immunohistochemistry in an independent validation series of 83 FLs. Statistical analysis identified 17 microRNAs that were differentially expressed between t(14;18)-positive FLs and t(14;18)-negative FLs. The down-regulation of miR-16, miR-26a, miR-101, miR-29c, and miR138 in the t(14;18)-negative FL subset was associated with profound mRNA expression changes of potential target genes involving cell cycle control, apoptosis, and B-cell differentiation. miR-16 target CHEK1 showed increased expression in t(14;18)-negative FLs, whereas TCL1A expression was reduced, in line with a partial loss of the germinal center B-cell phenotype in this FL subset. In conclusion, t(14;18)-negative FL have distinct microRNA profiles that are associated with an increased proliferative capacity and a "late" germinal center B-cell phenotype.

Disturbed expression of the T-cell receptor/CD3 complex and associated signaling molecules in CD30+ T-cell lymphoproliferations.

BACKGROUND: CD30(+) T-cell lymphoproliferations comprise a spectrum of clinically heterogeneous entities, including systemic anaplastic large cell lymphomas (ALK(-) and ALK(+)) and primary cutaneous CD30(+) T-cell lymphoproliferative disorders. While all these entities are characterized by proliferation of highly atypical, anaplastic CD30(+) T cells, the expression of T-cell specific antigens in the tumor cells is not consistently detectable. DESIGN AND METHODS: We evaluated biopsies from 19 patients with primary cutaneous CD30(+) lymphoproliferative disorders, 38 with ALK(-) and 33 with ALK(+) systemic anaplastic large cell lymphoma. The biopsies were examined for the expression of T-cell receptorαß/CD3 complex (CD3γ, δ, ε, ζ), transcription factors regulating T-cell receptor expression (ATF1, ATF2, TCF-1, TCF-1α/LEF-1, Ets1), and molecules of T-cell receptor-associated signaling cascades (Lck, ZAP-70, LAT, bcl-10, Carma1, NFATc1, c-Jun, c-Fos, Syk) using immunohistochemistry. RESULTS: In comparison to the pattern in 20 peripheral T-cell lymphomas, not otherwise specified, we detected a highly disturbed expression of the T-cell receptor/CD3 complex, TCF-1, TCF-1α/LEF-1, Lck, ZAP-70, LAT, NFATc1, c-Jun, c-Fos and Syk in most of the systemic anaplastic large cell lymphomas. In addition, primary cutaneous CD30(+) lymphoproliferative disorders showed such a similar expression pattern to that of systemic anaplastic large cell lymphomas, that none of the markers we investigated can reliably distinguish between these CD30(+) T-cell lymphoproliferations. CONCLUSIONS: Severely altered expression of the T-cell receptor/CD3 complex, T-cell receptor-associated transcription factors and signal transduction molecules is a common characteristic of systemic and cutaneous CD30(+) lymphoproliferations, although the clinical behavior of these entities is very different. Since peripheral T-cell lymphomas, not otherwise specified retain the full expression program required for functioning T-cell receptor signaling, the differential expression of a subset of these markers might be of diagnostic utility in distinguishing peripheral T-cell lymphomas, not otherwise specified from the entire group of CD30(+) lymphoproliferations.

Pediatric supratentorial ependymomas show more frequent deletions on chromosome 9 than infratentorial ependymomas: a microsatellite analysis.

Numerous human malignancies, including brain tumors, have been reported to show aberrations on chromosome 9. In our previous screening study in ependymomas, we used microsatellite analysis to identify frequent aberrations on this chromosome. To refine our preliminary analysis of candidate regions, here we use 15 polymorphic microsatellite markers spanning the entire chromosome 9. A total of 48 pairs of matched normal and tumor specimens from patients with ependymoma, including 28 children (mean age, 4.4 years) and 20 adults (mean age, 44.9 years), were genotyped. Allelic imbalances were found in 30/48 patients (62.5%). Pediatric tumors, which were predominantly anaplastic, showed fewer aberrations (57.1%) than adult tumors (70%), and two common regions of deletions were identified (9p21.1 approximately p22.3 and 9q31.3 approximately q33.2). We found that 9q31.3 approximately q33.2, an approximately 8.5-megabase segment containing the DCR1 gene, exhibited the highest number of aberrations (n=33). Adults with ependymomas harboring aberrations on chromosome 9 (n=14) showed significantly longer overall survival than patients of the same group without this aberration (n=6; P=0.034), irrespective of the extent of resection in multivariate analysis. Aberrations of chromosome 9, and particularly of DCR1, may play a role in the prognostic evaluation for ependymomas in adults in the future. In pediatric patients, genetic aberrations were found significantly more often in supratentorial tumors than in tumors with infratentorial location (P=0.007). This result may underscore differences in the origin of these tumors.

Lymphangiosis carcinomatosa in squamous cell carcinomas of larynx and hypopharynx--value of conventional evaluation and additional immunohistochemical staining of D2-40.

BACKGROUND: Recent studies revealed a predictive value of lymphatic vessel invasion (L1) for the nodal metastasizing and poor prognosis in malignant tumors at different sites. The monoclonal antibody D2-40 (podoplanin) stains specifically endothelial cells of lymphatic vessels and improves the search for L1. However, the importance of this immunohistochemical staining was not investigated in squamous cell carcinomas (SCC) of larynx and hypopharynx. AIM: This study was performed to compare the diagnostic potential of conventional and immunohistochemical determination of L1 in SCC of larynx and hypopharynx with special respect to the predictive value for nodal metastasizing and prognosis. METHODS: 119 SCCs of the larynx (n = 70) respectively hypopharynx (n = 49) were investigated. The lymphatic vessel invasion was assessed by conventional method (HE stain) and immunohistochemical staining with an antibody against D2-40 (DAKO, Germany). Immunohistochemistry was performed in accordance with manufacturer's protocol. L1 was searched microscopically in a standardized magnification (x200) in serial sections of tumor samples (1 section per cm tumor diameter). RESULTS: The immunohistochemical investigation did not show significant advantages for the prediction of regional nodal metastases. Despite a low sensitivity (< 50%) in both methods, the specificity can reach 80%. The negative predictive value in both methods seems acceptable (up to 80%), whereas the positive predictive value is not higher than 64%. Cases with L1 detected either conventionally or immunohistochemically did not show a significant shorter survival than cases with L0. However, a non-significant shorter survival was found. Only in SCC of hypopharynx, a combination of both methods revealed patients with a significant worse prognosis. CONCLUSION: The status of lymphatic vessel invasion should be documented in standardized tumor reports. A benefit of an additional immunohistochemical investigation was not found, for the daily routine HE-stain seems sufficient.

Delineation of distinct tumour profiles in mantle cell lymphoma by detailed cytogenetic, interphase genetic and morphological analysis.

Mantle cell lymphoma (MCL) is an aggressive lymphoid tumour characterized by the translocation t(11;14)(q13;q32) and a poor clinical outcome (median survival: 3-4 years). Recent studies revealed that increased proliferation of the tumour cells and certain chromosomal aberrations, such as deletions of 17p13 and 9p21 represent major adverse biological markers in this disease, although the molecular targets of chromosomal imbalances in MCL have not been identified for the large majority of loci affected. To correlate histomorphological and proliferation features of MCL with genetic findings, we investigated 223 MCL by fluorescence in situ hybridization (FISH) (n = 157) and/or classical cytogenetic banding analysis (n = 129). FISH analysis turned out to be distinctly more sensitive in the delineation of aberrations. Complex karyotypic alterations were associated with higher proliferation indices and inferior prognosis. A comprehensive analysis of biological features including genetic alterations in MCL by hierarchical clustering resulted in the delineation of four tumour subgroups differing with respect to their genetic constitution and suggesting different transformation or progression pathways. Moreover, in one of the groups identified, a more indolent clinical behaviour was associated with few secondary aberrations and fewer known high-risk chromosomal aberrations, which points to the importance of the quality of karyotypic evolution in MCL tumours.

Correlation between 6q25.3 deletion status and survival in pediatric intracranial ependymomas.

Losses and rearrangements of genetic material on chromosome 6q are frequently found in several human malignancies, including primary central nervous system tumors. We previously used microsatellite analysis of ependymomas to identify frequent deletions in regions 6q15 approximately q16, 6q21 approximately q22.1, and 6q24.3 approximately q25.3. To refine our preliminary analysis of potential prognostic regions, we used a panel of 25 microsatellite markers located between 6q15 and 6qter in 49 pairs of matched normal and tumor specimens from 28 children and 21 adults with ependymoma. Allelic deletions were detected in 34 of 49 patients (69%), and two common regions of deletions (6q24.3 and 6q25.2 approximately q25.3) were identified. A short segment of approximately 0.4 Mb between D6S1612 and D6S363 on 6q25.3, containing the SNX9 and SYNJ2 genes, exhibited the highest number of aberrations (n = 38). Pediatric tumors showed slightly fewer aberrations (64%) than adult tumors (76%) and also predominantly exhibited small interstitial deletions, in contrast to the extensive losses of genetic material in adults. Pediatric anaplastic intracranial (supra- and infratentorial) ependymomas harboring the 6q25.3 deletion (n = 9) showed significantly longer overall survival than did patients of the same group without the aberration (n = 6), independent of the extent of resection (P = 0.013). This supports the identified deletion on 6q25.3 as a candidate favorable prognostic parameter and warrants further investigation.

Analysis of single nucleotide polymorphisms in the FAS and CTLA-4 genes of peripheral T-cell lymphomas.

Angioimmunoblastic T-cell lymphoma (AILT) represents a subset of T-cell lymphomas but resembles an autoimmune disease in many of its clinical aspects. Despite the phenotype of effector T-cells and high expression of FAS and CTLA-4 receptor molecules, tumor cells fail to undergo apoptosis. We investigated single nucleotide polymorphisms (SNPs) of the FAS and CTLA-4 genes in 94 peripheral T-cell lymphomas. Although allelic frequencies of some FAS SNPs were enriched in AILT cases, none of these occurred at a different frequency compared to healthy individuals. Therefore, SNPs in these genes are not associated with the apoptotic defect and autoimmune phenomena in AILT.

Tumor recurrence and survival in patients treated for thymomas and thymic squamous cell carcinomas: a retrospective analysis.

PURPOSE: Thymic epithelial tumors (TET) are rare epithelial neoplasms of the thymus with considerable histologic heterogeneity. This retrospective study focused on the correlation of WHO-defined TET histotypes with survival and tumor recurrence in a large cohort of patients receiving different modes of treatment. PATIENTS AND METHODS: Two hundred twenty-eight patients were followed for up to 21 years (median, 60 months; range, 1 to 252 months) after primary surgery. Forty-two patients received adjuvant radiotherapy (mean dose, 53 Gy), and 33 patients received adjuvant chemotherapy. RESULTS: Seventy-six (88%) of 86 patients with WHO type A, AB, and B1 thymomas were treated by surgery alone, with three tumor relapses after 3 to 10 years (median, 3.4 years). Twelve of 67 patients with WHO type B2 and B3 thymomas in Masaoka stages I and II were treated by adjuvant radiotherapy without evidence of tumor recurrence after 1 to 12 years (median, 4 years). Among 75 patients with B2 and B3 thymomas with incomplete resection or a tumor stage III or higher, the recurrence rate was 34% (n = 23) after 0.5 to 17 years (median, 5 years) in patients receiving adjuvant radiochemotherapy, compared to 78% (seven of nine patients) in patients without adjuvant radiochemotherapy. Incomplete tumor resection was associated with a high recurrence rate (65%) and a poor prognosis (P <.01). CONCLUSION: The long-term outcome of TET patients is related to tumor stage, WHO histotype, completeness of surgical removal, and type of treatment. Prospective trials are warranted to formally address the efficacy of adjuvant therapy in the treatment of localized and advanced malignant TETs.

Chromosomal gains at 9q characterize enteropathy-type T-cell lymphoma.

Genetic alterations in enteropathy-type T-cell lymphoma (ETL) are unknown so far. In this series, 38 cases of ETL were analyzed by comparative genomic hybridization (CGH). CGH revealed chromosomal imbalances in 87% of cases analyzed, with recurrent gains of genetic material involving chromosomes 9q (in 58% of cases), 7q (24%), 5q (18%), and 1q (16%). Recurrent losses of genetic material occurred on chromosomes 8p and 13q (24% each), and 9p (18%). In this first systematic genetic study on ETL, chromosomal gains on 9q (minimal overlapping region 9q33-q34) were found to be highly characteristic of ETL. Fluorescence in situ hybridization analysis on four cases of ETL, using a probe for 9q34, indicated frequent and multiple gains of chromosomal material at 9q34 (up to nine signals per case). Among 16 patients with ETL who survived initial disease presentation, patients with more than three chromosomal gains or losses (n = 11) followed a worse clinical course than those with three or less imbalances (n = 5). The observation of similar genetic alterations in ETL and in primary gastric (n = 4) and colonic (n = 1) T-cell lymphoma, not otherwise specified, is suggestive of a genetic relationship of gastrointestinal T-cell lymphomas at either localization.

New WHO histologic classification predicts prognosis of thymic epithelial tumors: a clinicopathologic study of 200 thymoma cases from China.

BACKGROUND: In 1999, a World Health Organization (WHO) committee published histologic criteria for distinct thymoma entities (labeled as Type A, AB, B1, B2, B3 thymomas) and for the heterogeneous group of thymic carcinomas, collectively called Type C thymomas. Whether WHO-defined histologic thymoma subtypes are of independent prognostic relevance has yet to be proved. METHODS: Two hundred thymomas from the Shanghai Chest Hospital with a mean follow-up time of 15 years (range, 1-246 months) were studied for the relevance of WHO histologic subtype and other factors (stage, therapy, and myasthenia gravis [MG]) for survival. RESULTS: In order of frequency, 68 patients (34.0%) had Type AB, 39 (19.5%) had Type B2, 36 (18.0%) had Type C, 27 (13.5%) had Type B3, 17 (8.5%) had Type B1, and 8 (4.0%) had Type A thymoma. Five cases (2.5%) were rare thymomas not mentioned in the WHO classification. Survival data showed significant differences among the histologic subtypes (log rank test: P < 0.001). Among patients with Type A and AB thymomas, none died of tumor; of the Type B1 thymoma patients, only one (5.9%) died at 22 months. Type B2, B3, and C thymomas had a significantly worse prognosis with 5-year survival rates of 75.0%, 70.0%, and 48.0%, respectively. Ninety-six patients (48.0%) were in Masaoka Stage I, 26 (13.0%) were in Stage II, 65 (32.5%) were in Stage III, and 13 (6.5%) were in Stage IV. Stage was highly significant in predicting survival (log rank, test P < 0.001). The association between histologic subtype and invasive behavior (stage) was statistically significant (P < 0.001). However, histology was an independent predictive factor of survival in Stage I and II thymomas: Type B2, B3, and C thymomas had a worse prognosis than Type A, AB, and B1 thymomas (log rank test: P < 0.003). Thirty patients (15.0%) presented with MG. MG was significantly more frequent in Type B2 and B3 than in Type A, AB, and B1 thymomas (P < 0.01). On multivariate analysis, MG had no adverse effect on survival (P = 0.17). Radiation or chemotherapy improved patients' survival at 5 and 10 years in Type B2, B3, and C thymomas (log rank test: P < 0.003). CONCLUSIONS: Tumor stage is the most important determinant of survival in thymoma patients, but the WHO histologic subtype is an independent prognostic factor in Stage I and II thymomas, among which WHO Type A, AB, and B1 thymomas form a low-risk group. Patients with high-risk thymomas might profit from novel adjuvant radiochemotherapy regimens.