[Show abstract][Hide abstract] ABSTRACT: Recent advances in the diagnostic of myeloproliferative neoplasms discovered CALRETICULIN (CALR) mutations as a major driver in these disorders. In contrast to JAK2 mutations being mainly associated with polycythaemia vera, CALR mutations are only associated with primary myelofibrosis (PMF) and essential thrombocythaemia (ET). CALR mutations are present in the majority of primary myelofibrosis and essential thrombocythaemia patients lacking JAK2 and MPL mutations. Since these CALR mutations are absent from reactive bone marrow lesions their presence indicates ET or PMF. So far these mutations are detectable only by molecular assays. Their molecular detection is cumbersome because of the great CALR mutation heterogeneity. Therefore, the availability of a simple assay would be of great help. All CALR mutations reported lead to a frameshift generating a new 36 amino acid C-terminus. We generated a monoclonal antibody (CAL2) to this C-neoterminus by immunizing mice with a representative peptide and compared its performance with Sanger sequencing data in 173 myeloproliferative neoplasms (MPNs) and other bone marrow (BM) diseases. There was a 100% correlation between the molecular and the CAL2 immunohistochemical (IHC) assays. Thus, the detection of CALR mutations by the CAL2 IHC is a specific, sensitive, rapid, simple and low-cost method.Leukemia accepted article preview online, 23 July 2015. doi:10.1038/leu.2015.192.
Leukemia: official journal of the Leukemia Society of America, Leukemia Research Fund, U.K 07/2015; DOI:10.1038/leu.2015.192 · 10.43 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Prognostically-relevant risk factors in patients with diffuse large B-cell lymphoma (DLBCL) have predominantly been evaluated in elderly populations. We tested whether previously described risk factors are also valid in younger, poor-prognosis DLBCL patients. Paraffin-embedded samples from 112 patients with de novo DLBCL, enrolled in the R-MegaCHOEP trial of the German High Grade Non-Hodgkin Lymphoma Study Group (DSHNHL) were investigated using immunohistochemistry (MYC, FOXP1, LMO2, GCET1, CD5, CD10, BCL2, BCL6, IRF4/MUM1) and fluorescence in situ hybridization (MYC, BCL2, BCL6). MYC, BCL2 and BCL6 breaks occurred in 14%, 21% and 31%, respectively. In the majority of cases, MYC was simultaneously rearranged with BCL2 and/or BCL6. The adverse impact of MYC rearrangements was confirmed, but the sole presence of BCL2 breaks emerged as a novel prognostic marker associated with inferior overall survival (OS) (p=0.002). Combined over-expression of MYC and BCL2 showed only limited association with inferior OS. All immunohistochemical cell of origin (COO) classifiers applied failed to predict survival time. DLBCL tumors with significant proportion of immunoblastic and/or immunoblastic-plasmacytoid cells had inferior OS, independently from from BCL2 break. Younger, poor-prognosis DLBCL patients, therefore, display different biological risk factors compared to an elderly population, with BCL2 translocations emerging as a powerful negative prognostic marker.Leukemia accepted article preview online, 17 February 2015. doi:10.1038/leu.2015.43.
[Show abstract][Hide abstract] ABSTRACT: The objective of this registry study was to analyze the outcome of patients who underwent allogeneic or autologous hematopoietic stem cell transplantation (HSCT) for hepatosplenic T cell lymphoma (HSTL), a rare and extremely aggressive peripheral T cell lymphoma subtype. Patients were eligible if they had histologically verified HSTL and underwent HSCT between 2003 and 2011. 76 patients were identified in the EBMT database. Additional baseline and follow-up information could be obtained from the referring centres for 36 patients. Eleven of these were excluded following histopathology review, leaving 25 patients in the final study cohort (alloHSCT 18, autoHSCT 7). With a median follow-up of 36 months, 2 patients relapsed after alloHSCT, resulting in a 3-year progression-free survival of 48%. After autoHSCT, 5 patients relapsed and subsequently died. This study indicates that graft-versus-lymphoma activity conferred by alloHSCT can result in long-term survival for a substantial proportion of patients with HSTL.Leukemia accepted article preview online, 19 September 2014. doi:10.1038/leu.2014.280.
[Show abstract][Hide abstract] ABSTRACT: Burkitt lymphoma is reported by the World Health Organization as a highly aggressive B-cell lymphoma. Three clinical variants of Burkitt lymphoma are recognized (endemic, sporadic, immunodeficiency-associated), which differ in geographic distribution, clinical presentation, and association with infectious agents and cell biology. The tumor is composed by monomorphic medium-sized B-cells with basophilic cytoplasm, numerous mitotic figures, and an extremely high proliferation rate (Ki-67-index >95 %). A “starry sky” pattern is usually present, due to numerous benign macrophages that have ingested apoptotic tumor cells. Tumor cells express membrane IgM with light chain restriction and B-cell-associated antigens CD19, CD20, CD22, and CD79a. Chromosomal translocation involving MYC is the most frequent genetic feature; however, some cases lack MYC translocation. No singleparameter (such as morphology, genetic analysis, or immunophenotyping) can be used as the gold standard for the diagnosis of BL, but a combination of several diagnostic techniques is necessary.
[Show abstract][Hide abstract] ABSTRACT: Background:
The detection of characteristic genomic aberrations by fluorescence in situ hybridization (FISH) has a high diagnostic impact on lymphomas according to the World Health Organization (WHO). To investigate the reproducibility of non-isotopic ISH results a multicenter trial was carried out involving eight institutes for hematopathology.
Material and methods:
Analyses were performed on two diffuse large B-cell lymphomas (DLBCL) without known aberrations, on one follicular lymphoma with a IGH/BCL2 translocation and BCL6 split and on two B-cell lymphomas intermediate between DLBCL and Burkitt's lymphoma with c-MYC and BCL2 rearrangements, one with an additional BCL6 split. Break-apart probes for BCL6 and c-MYC, as well as fusion probes for the c-MYC/IGH and the IGH/BCL2 translocations were used.
All aberrations were correctly detected by all centres and no false positive or false negative results were obtained. The numbers of positive cells varied from 25% to 94%. Pearson's correlation coefficient between the centres was always > 0.8.
The ISH analysis of recurrent genomic aberrations in formalin-fixed paraffin-embedded (FFPE) tissue is a highly reproducible technique which yields substantial additive help for lymphoma diagnostics.
Der Pathologe 11/2012; 34(4). DOI:10.1007/s00292-012-1719-0 · 0.39 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To study the expression of CD2-associated protein (CD2AP), an adaptor protein involved in T-cell signalling and renal function, in normal, reactive and neoplastic human lymphoid tissues.
We used immunohistochemical techniques to evaluate monoclonal antibodies against CD2AP on over 400 formalin fixed paraffin embedded tissue blocks retrieved from the host institutions of three authors. The samples tested included normal, reactive and neoplastic lymphoid tissue. In lymphoid tissues, strong CD2AP staining was observed in plasmacytoid dendritic cells (pDCs), weak and variable in mantle zone B cells and moderate in rare germinal center cells. CD2AP labeled cortical and rare medullary thymocytes and isolated mononuclear cells in bone marrow trephines. Furthermore, epithelial and endothelial cells expressed CD2AP. Among neoplasms, the greatest number of CD2AP-positive cases were found in diffuse large B cell (21/94), NK T-cell lymphomas (7/67), "blastic plasmacytoid dendritic cell neoplasms" (9/10) and some types of solid tumor.
Our finding that mature peripheral T cells are CD2AP-negative but immature cortical thymocytes are positive may prove useful for diagnostic purposes. Moreover, our results demonstrate that CD2AP represents a useful marker of normal and neoplastic pDC and may be used in a diagnostic panel in reactive or neoplastic lymphoid proliferations.
[Show abstract][Hide abstract] ABSTRACT: Leukemia is one of the leading journals in hematology and oncology. It is published monthly and covers all aspects of the research and treatment of leukemia and allied diseases. Studies of normal hemopoiesis are covered because of their comparative relevance.
Leukemia: official journal of the Leukemia Society of America, Leukemia Research Fund, U.K 02/2012; 26(7):1707-10. DOI:10.1038/leu.2012.27 · 10.43 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Sporadic Burkitt lymphoma (sBL) can be delineated from diffuse large B-cell lymphoma (DLBCL) by a very homogeneous mRNA expression signature. However, it remained unclear whether all three BL variants-sBL, endemic BL (eBL) and human immunodeficiency virus-associated BL (HIV-BL)-represent a uniform biological entity despite their differences in geographical occurrence, association with immunodeficiency and/or incidence of Epstein-Barr virus (EBV) infection. To address this issue, we generated micro RNA (miRNA) profiles from 18 eBL, 31 sBL and 15 HIV-BL cases. In addition, we analyzed the miRNA expression of 86 DLBCL to determine whether miRNA profiles recapitulate the molecular differences between BL and DLBCL evidenced by mRNA profiling. A signature of 38 miRNAs containing MYC regulated and nuclear factor-kB pathway-associated miRNAs was obtained that differentiated BL from DLBCL. The miRNA profiles of sBL and eBL displayed only six differentially expressed miRNAs, whereas HIV and EBV infection had no impact on the miRNA profile of BL. In conclusion, miRNA profiling confirms that BL and DLBCL represent distinct lymphoma categories and demonstrates that the three BL variants are representatives of the same biological entity with only marginal miRNA expression differences between eBL and sBL.
Leukemia: official journal of the Leukemia Society of America, Leukemia Research Fund, U.K 06/2011; 25(12):1869-76. DOI:10.1038/leu.2011.156 · 10.43 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Eosinophilic ulcer of the oral mucosa is a benign lesion of unclear pathogenesis mostly affecting the tongue. It has been suggested to represent a reactive pattern to several stimuli. We report on a 12-year-old boy who presented with a painless infiltrating ulcer on the gingiva of the lower jaw, which was covered by necrotic yellowish slough. There were no pathologic features of the jawbones or regional lymph nodes. Histopathological, immunohistochemical and gene rearrangement studies were in agreement with eosinophilic ulcer with predominant oligoclonal CD3+ and CD30+ T lymphocytes expressing the Epstein-Barr virus membrane protein. The ulcer resolved within 4 weeks and follow-up for 3 years revealed no evidence of recurrence. Epstein-Barr virus may have played a role in triggering this reactive lymphoproliferative disorder.
[Show abstract][Hide abstract] ABSTRACT: Die 2008 aktualisierte WHO-Klassifikation der lymphatischen Neoplasien stellt einen weltweiten Konsensus über die Diagnose dieser Tumoren dar. Sie basiert auf einem multidisziplinären Ansatz zur Definition von eigenständigen Lymphomentitäten. Bekannte Lymphomkrankheiten wurden genauer definiert, neue Entitäten identifiziert sowie neue Konzepte und Erkenntnisse, die zu einem besseren Verständnis der malignen Lymphome beitragen, integriert. Eine Reihe von Fragen blieben allerdings ungelöst. Zu diesen gehörten insbesondere die Frage, welcher Grad genetischer oder molekularer Veränderungen für die Definition einer eigenständigen Lymphomentität notwendig ist und der Status der provisorischen Entitäten. In der Zeit nach der Veröffentlichung der WHO-Klassifikation von 2008 gab es eine Reihe neuer wissenschaftlicher Beobachtungen. Außerdem wurden neue Konzepte zum Verständnis der malignen Lymphome entwickelt. Dieser Fortschritt ist der Schwerpunkt nach folgender Übersicht, soweit er Einfluss auf die diagnostischen Kriterien hat.
Der Onkologe 01/2011; 17(9). DOI:10.1007/s00761-011-2126-5 · 0.14 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Current mouse models do not reflect the sporadic nature of colon cancer and do not allow the analysis of antitumor immune response because of the lack of known tumor-specific antigens. Two transgenic mouse models with spontaneous tumor development were generated, directing the expression of SV40T antigen (Tag) either constitutively (Vil-Cre × LoxP-Tag-transgenic mice) or stochastically (Vil-Cre-ER(T2) × LoxP-Tag-transgenic mice) into the putative stem cell region of the crypt of Lieberkühn. Tumor development and antitumor immune response were monitored. Vil-Cre × LoxP-Tag mice developed multiple adenocarcinomas of the small intestine and colon at an average age of 6 months. During the tumor development, Tag-specific immunoglobulin G (IgG) antibodies were induced in half of the mice, although they had developed neonatal cytotoxic T lymphocyte (CTL) tolerance. This model shows similarity to hereditary colon cancer but not to the sporadic tumor development. Therefore, the conditional Vil-Cre-ER(T2) × LoxP-Tag mice were established, in which expression of the dormant Tag was induced by stochastic, tissue-specific activation of Cre recombinase. These mice spontaneously developed highly invasive, metastasizing colon carcinomas at an average age of 20 months. Colon carcinomas expressed epithelial and/or neuroendocrine markers depending on the grade of differentiation. Young Vil-Cre-ER(T2) × LoxP-Tag mice had retained CTL responses against epitope IV of Tag. The tumors induced strong anti-Tag IgG responses. We report, for the first time, a mouse model based on stochastic, tissue-specific activation of a dormant oncogene in the colon allowing the analysis of antitumor immune response against primary colorectal cancer.
[Show abstract][Hide abstract] ABSTRACT: Inappropriate activation of the NOTCH signaling pathway, for example, by activating mutations, contributes to the pathogenesis of various human malignancies. Here, we demonstrate that aberrant expression of an essential NOTCH coactivator of the Mastermind-like (MAML) family provides an alternative mechanism to activate NOTCH signaling in human lymphoma cells. We detected high-level MAML2 expression in several B cell-derived lymphoma types, including classical Hodgkin lymphoma (cHL) cells, relative to normal B cells. Inhibition of MAML-protein activity by a dominant negative form of MAML or by small hairpin RNAs targeting MAML2 in cHL cells resulted in downregulation of the NOTCH target genes HES7 and HEY1, which we identified as overexpressed in cHL cells, and in reduced proliferation. Furthermore, a NOTCH gene-expression signature in cHL cells confirmed their cell-autonomous NOTCH activity. Finally, in line with the essential role of MAML proteins for assembly and activity of the NOTCH transcriptional complex (NTC), we show that MAML-derived small-peptide constructs block NOTCH activity and disrupt NTC formation in vitro. These data strongly suggest direct targeting of the NTC as treatment strategy for NOTCH-dependent malignancies.
[Show abstract][Hide abstract] ABSTRACT: The case of a 59-year-old patient is described who presented with a left-sided pressure sensation in the left orbit and exophthalmus with a proud bulbus. The limited bulbus motility led to double vision. A preoperative MRI showed a space-occupying lesion in the left medial orbit. The morphological and immunohistochemical findings led to the diagnosis of a primary ductal carcinoma resembling salivary duct carcinoma (SDC). The tumor could be removed without compromising the eye. The patient suffers no side-effects or recurrences 12 months later.
Der Pathologe 07/2010; 31(4):279-82. · 0.39 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Vorgestellt wird der Fall eines 59-jährigen Patienten, der mit Druckgefühl in der linken Orbita und Exophthalmus mit Bulbushochstand
linksseitig vorstellig wurde. Die eingeschränkte Bulbusmotilität führte zu Doppelbildern. Die präoperative MRT zeigte eine
Raumforderung der linken medialen Orbita. Die morphologischen und immunhistologischen Befunde führten zu der Diagnose eines
primären duktalen Karzinoms vom Speichelgangtyp (SDC). Der Tumor konnte unter Organerhaltung des Auges entfernt werden. Der
Patient ist 12Monate nach der Behandlung beschwerde- und tumorfrei.
The case of a 59-year-old patient is described who presented with a left-sided pressure sensation in the left orbit and exophthalmus
with a proud bulbus. The limited bulbus motility led to double vision. A preoperative MRI showed a space-occupying lesion
in the left medial orbit. The morphological and immunohistochemical findings led to the diagnosis of a primary ductal carcinoma
resembling salivary duct carcinoma (SDC). The tumor could be removed without compromising the eye. The patient suffers no
side-effects or recurrences 12 months later.
SchlüsselwörterEpitheliale Neoplasie-Speichelgangkarzinom-Duktales Wachstumsmuster-Androgenrezeptor
KeywordsEpithelial neoplasm-Salivary duct carcinoma-Ductal growth pattern-Androgen receptor
Der Pathologe 07/2010; 31(4):279-282. DOI:10.1007/s00292-010-1291-4 · 0.39 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The polymerase chain reaction (PCR) procedure was used for rapid and highly specific amplification of the t(14;18) bcl-2/JH DNA junctional regions in B-cell lymphomas. By using Taq-polymerase and relatively long oligonucleotide primers–a 33-mer for bcl-2 and an universal 25-mer complementary to the JH consensus sequence–the primer annealing and primer extension steps could be carried out at the same temperature (70°C), thus markedly reducing the reaction time and significantly improving the specificity of the reaction. The specificity of the amplification allowed visual identification of the bcl-2/JH PCR-products in ethidium bromide stained agarose gels. DNA-sequence analysis of PCR-amplified, previously uncharacterized t(14; 18) junctional regions, confirmed the specificity of this assay. Moreover, preliminary data show that the procedure is capable of documenting the presence of occult lymphoma cells in both the peripheral blood and bone marrow.
Leukemia and Lymphoma 06/2009; 3(2):109-117. DOI:10.3109/10428199009050984 · 2.89 Impact Factor