Publications by authors named "Dallenbach F"

Currently, lymphoma diagnosis is based on a combination of morphology, immunophenotyping, and molecular testing. Using the example of an unusual case of malignant non-Hodgkin lymphoma, we show that improved visualization using digital pathology contributes to the convergence of these complementary diagnostic modalities. A 45-year-old woman presented with skin rash and cervical lymphadenopathy.

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Article Synopsis
  • Lymphoma affecting the dura mater is rare and primarily linked to extranodal marginal zone lymphoma of MALT type.
  • A case is presented involving a patient with a meningeal tumor identified as a B-cell lymphoproliferative disorder resembling chronic lymphocytic leukemia.
  • The detection of trisomy 3 in the patient's bone marrow suggests that CD5(+) MALT lymphoma is a critical consideration, although it's not previously documented in dural lymphoma.
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The present study aimed to investigate oxytocin receptor (OTR) expression in the normal uterus, and particularly in uterine smooth muscle tumors and endometrial stromal sarcomas (ESSs) because these tumors can be difficult to distinguish. The expressions of OTR, CD10, h-caldesmon, calponin, smooth muscle actin, and desmin were analyzed in 10 conventional leiomyomas (LMs), 10 highly cellular leiomyomas (HCLs), eight leiomyosarcomas (LMSs), and nine ESSs. In five normal uteri and five cases of adenomyosis, OTR was strongly expressed in the myometrium and showed expression pronounced in the surface epithelium during the late proliferative phase and at the time of ovulation, whereas the endometrial stromal cells were negative.

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Article Synopsis
  • The study evaluated the effectiveness of quality assurance in immunohistochemistry within pathology labs across Germany, analyzing how well pathologists diagnosed cases requiring this technique.
  • The results showed that only 57% of diagnoses were correct, with various factors influencing the outcomes, including interpretation of stains and tentative diagnoses.
  • The main challenge identified was integrating immunohistochemistry into the overall diagnostic process, rather than issues with staining quality, highlighting the need for improved training and quality control in the field.
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Marginal zone B-cell lymphomas (MCL) of extranodal, nodal and splenic origin appear to be different lymphoma entities with a similar growth pattern in the marginal zone of the B-follicles. Decisive for the detection of MCL as a distinct lymphoma entity was the "MALT concept" for lymphoid infiltrates in the gastric and intestinal mucosa as described by Isaacson et al. in the 1980's.

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Basal cell adenocarcinoma was first introduced as an entity in the second edition of the WHO's "Histologic Typing of Salivary Gland Tumours" in 1991. This tumor was first described in 1990 by Ellis and Wiskovitch from the Armed Forces Institute of Pathology (AFIP). Basal cell adenocarcinoma accounts for about 2.

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Hodgkin's disease (HD) is associated with the Epstein-Barr virus (EBV) in approximately half of cases. This is a report of a case of nodular sclerosing HD of the B-cell type that was associated with EBV in the initial manifestation, but was found to be EBV-negative in the relapse of the tumour. Both tumours displayed similar clinical, pathological, and immunohistochemical features.

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We report here a series of 16 highly malignant diffuse large B-cell lymphomas of the oral cavity with unique immunohistologic features. Fifteen of these developed in human immunodeficiency virus-positive patients. All cases displayed morphologic features of diffuse large-cell lymphomas but strikingly differed from them in that they showed a minimal or absent expression of the leukocyte common antigen as well as of the B-cell antigen CD20.

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The CD79 molecule, comprising two polypeptide chains, mb-1 (CD79a) and B29 (CD79b), is physically associated in the B-cell membrane with immunoglobulin. It transmits a signal after antigen binding and may, therefore, be considered the B cell equivalent of CD3. It appears before the pre-B-cell stage, and the mb-1 (CD79a) chain can still be present at the plasma cell stage.

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Lymph node biopsies from 140 cases of Hodgkin's disease (HD) and from 30 non-malignant lesions were screened for the presence of t(14;18) translocations involving the major breakpoint region (mbr) of the bcl-2 gene and the joining region (JH) of the immunoglobulin heavy chain gene, using a polymerase chain reaction (PCR) assay with subsequent nucleotide sequencing of amplified bcl-2/JH junctional regions. Expression of the bcl-2 protein within the Hodgkin and Reed-Sternberg (HRS) cells was investigated in 86 cases of HD by immunohistochemistry on cryostat or paraffin sections. Although bcl-2 expression could be found in a proportion of neoplastic cells in up to one-third of HD cases, the frequency of t(14;18) gene fusions detected by PCR was low.

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Primary infection with Epstein-Barr virus (EBV) may arise as infectious mononucleosis (IM) in adolescents and young adults. Morphologically, IM-affected lymphoid tissue is characterized by expanded interfollicular areas with formation of atypical lymphoid blasts. It is assumed that morphology and clinical presentation of IM are related to characteristic patterns of cytokine production by EBV-infected and reactive cells.

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Hodgkin (H) and Reed-Sternberg (RS) cells are considered to be the malignant cell population in Hodgkin's disease (HD). To date, their analysis has been hampered by their scarcity in primary tumors, poor growth in vitro, and lack of an animal model. To establish an in vivo system for the characterization of the malignant cells in HD, tumor biopsy samples from 13 HD patients were transplanted beneath the renal capsule or into the liver of severe combined immunodeficient (SCID) mice.

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We investigated 81 cases of peripheral pleomorphic T-cell lymphoma (PMTCL) occurring in human immunodeficiency virus-negative Europeans for the presence of Epstein-Barr virus (EBV)-DNA through polymerase chain reaction (PCR) for the presence of EBV-encoded small nuclear RNAs (EBER) and immediate early mRNAs (Bam H-fragment, lower strand frame [BHLF]) by in situ hybridization (ISH) and for EBV-encoded latent membrane protein (LMP) and nuclear antigen 2 (EBNA2) by immunohistology (IH). EBER-ISH, which could be applied on all cases, showed an overall incidence of EBV-infected cells in 38 of 81 cases (47%) of PMTCL. These data could be confirmed by PCR, which produced congruent results in the cases with amplifiable DNA.

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To elucidate the role of CD3 eta in thymic development and to determine whether CD3 eta is involved in the negative selection process, CD3 eta was overexpressed > 100 fold in transgenic (tg) mice using a Thy-1 promoter and regulatory elements. CD3 eta was readily observed in the majority of cortical thymocytes and in a fraction of medullary thymocytes in tg mice by immunohistochemical staining with an anti-CD3 eta-specific mAb. In contrast, endogenous CD3 eta levels were too low to detect in normal littermates.

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The present study was performed to clarify the reported inconsistencies regarding the frequency of the association of Epstein-Barr virus (EBV) and Hodgkin's disease (HD). Biopsies from 102 patients with HD were screened for the presence of EBV-encoded small nuclear RNA (EBER) and latent membrane protein (LMP) by using a non-isotopic in situ hybridization (ISH) and immunohistology (IH), respectively. The results were additionally compared with those obtained by polymerase chain reaction (PCR) for EBV-DNA detection.

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Three patients with HIV-associated Kaposi sarcoma were treated with human recombinant granulocyte colony stimulating factor (G-CSF). They had all developed leucopenia during treatment with recombinant interferon-alpha-2a, in two cases combined with vincristine. In all three patients, there was an obvious rapid stimulation after s.

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In this study, 32 cases of T-cell lymphoma of angioimmunoblastic lymphadenopathy type (AILD-TCL) were investigated for their association with Epstein-Barr virus (EBV). For this purpose, three different approaches were applied: polymerase chain reaction (PCR) for the presence of EBV-DNA, in situ hybridization (ISH) for EBV-encoded small nuclear RNAs (EBER), and immunohistology for EBV-encoded latent membrane protein (LMP). PCR and EBER-ISH produced almost identical results, showing that all but one case of AILD-TCL contained EBV genomes.

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In recent years, techniques, probes, and reagents became available to reliably visualize individual Epstein-Barr virus (EBV)-infected cells, to assess EBV gene expression, and to analyze the clonal composition of EBV genomes in human tissues. Application of these techniques to more than 1000 lymphoid tissue specimens revealed (1) characteristic cellular and compartmental distribution patterns of EBV-infected cells in normal lymph nodes, reflecting the interference of EBV with physiologic B cell differentiation pathways, (2) an association of EBV with various mono- and oligoclonal lymphoproliferations ranging from benign conditions to overtly malignant lymphomas, and (3) characteristic patterns of EBV gene expression among EBV-associated lymphoproliferations. In the context of the established immortalizing and transforming properties of EBV, the findings support the concept of an etiologic role of EBV for cases of certain lymphomas such as Burkitt's lymphoma, anaplastic large cell lymphoma, Hodgkin's disease, and lymphomas arising in immunocompromised individuals.

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32 cases of T cell lymphoma of angioimmunoblastic lymphadenopathy type (AILD-TCL) were investigated for their association with Epstein-Barr virus (EBV). Polymerase chain reaction (PCR) for detection of EBV-DNA and in situ hybridization for EBV-encoded small nuclear RNAs (EBER) produced almost identical results, showing that all but one of AILD-TCL cases contained EBV genomes. Three distinctive patterns of EBV infection were observed after immunophenotypical characterization of EBER positive cells: 1.

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Epstein-Barr virus (EBV)-specific DNA sequences were detected by polymerase chain reaction analysis in 15 of 47 (32%) DNA extracts prepared from CD30-positive (Ki-1 antigen-positive) anaplastic large cell (ALC) lymphomas. EBV-encoded RNA (EBER) transcripts could be detected by in situ hybridization in the tumor cells of 9 of 11 EBV DNA-positive cases. Twenty-eight cases were examined by immunohistology on cryostat sections for the presence of the EBV-encoded latent membrane protein (LMP), the nuclear antigen 2 (EBNA2), the BZLF1 transactivator protein, and the late viral glycoprotein gp350/250.

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Cryostat sections from lymph nodes of 47 Hodgkin disease patients were examined by immunohistology for the Epstein-Barr virus (EBV)-encoded latent membrane protein (LMP), nuclear antigen 2, and late viral glycoprotein gp350/250. A distinct LMP-specific membrane and cytoplasmic staining was detected exclusively in Hodgkin and Reed-Sternberg cells in 18 patients (38%); EBV nuclear antigen 2 and gp350/250 immunoreactivity was absent in all instances. Thirty-two of 47 (68%) cases contained EBV-specific DNA sequences as detected by PCR, all LMP-positive cases being in this category.

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The development of T cells from stem (progenitor) cells to effector cells results from a two-wave process of proliferation and differentiation. The cells of the first differentiation wave are the precursor T cells, and those of the second differentiation wave are peripheral T cells. In the first differentiation wave, resting/circulating naive antigen-reactive T lymphocytes are produced which differ from each other in their antigen receptor-specificity.

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This review focuses on the cellular origin of Hodgkin and Reed-Sternberg (HRS) cells, their association with the Epstein-Barr virus (EBV), and their relation to Ki-1+ anaplastic large-cell (ALC) lymphoma. The tingibility of HRS cells in paraffin sections for polyclonal immunoglobulin represents a staining artifact and thus can no longer serve as an argument for the histiocytic nature of HRS cells. Immunolabeling studies do not support the putative relationship of HRS cells to cell types such as macrophages or interdigitating reticulum cells, but instead suggest: a) that lymphocyte-predominant (LP) Hodgkin's disease (HD) represents a B-cell neoplasm which is distinct from non-LP HD, and b) that non-LP HD constitutes a syndrome rather than a disease entity, with the existence of T-cell types and B-cell types.

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