[Revised version of the 4th edition of the WHO classification of malignant lymphomas : What is new?] / Revidierte Fassung der 4. Ausgabe der WHO-Klassifikation maligner Lymphome : Was ist neu?

After 8 years, the WHO has now published the updated version of the 4th edition of the classification of hematopoietic and lymphoid tumors. This update provides a conceptual rewrite of existing entities as well as some new provisional entities and categories, particularly among the aggressive B­cell lymphomas. Important new diagnostic categories include the high-grade B­cell lymphomas, the large B­cell lymphoma with IRF4 rearrangement, and the Burkitt-like lymphoma with 11q aberrations. Of particular importance, new concepts concerning the taxonomy and classification of early lymphoid lesions or precursor lesions are included, such as the in situ follicular neoplasia or the in situ mantle cell neoplasia. In addition, the concept of indolent lymphoproliferations, such as breast-implant-associated anaplastic large cell lymphoma and the indolent T­cell lymphoproliferative disorder of the gastrointestinal tract, has been strengthened. Finally, diagnostic criteria for existing lymphoma entities have been refined.

Accumulation of STIM1 is associated with the degenerative muscle fibre phenotype in ALS and other neurogenic atrophies.

AIM: Upon denervation, skeletal muscle fibres initiate complex changes in gene expression. Many of these genes are involved in muscle fibre remodelling and atrophy. Amyotrophic lateral sclerosis (ALS) leads to progressive neurodegeneration and neurogenic muscular atrophy (NMA). Disturbed calcium homeostasis and misfolded protein aggregation both in motor neurones and muscle fibres are key elements of ALS pathogenesis that are mutually interdependent. Therefore, we hypothesized that the calcium sensor STIM1 might be abnormally modified and involved in muscle fibre degeneration in ALS and other types of NMA. METHODS: We examined ALS and NMA patient biopsy and autopsy tissue and tissue from G93A SOD1 mice by immunohistochemistry and immunoblotting. RESULTS: In normal human and mouse muscle STIM1 was found to be differentially expressed in muscle fibres of different types and to concentrate at neuromuscular junctions, compatible with its known role in calcium sensing. Denervated muscle fibres of sALS and NMA cases and SOD1 mice showed diffusely increased STIM1 immunoreactivity along with ubiquitinated material. In addition, distinct focal accumulations of STIM1 were observed in target structures within denervated fibres of sALS and other NMA as well as SOD1 mouse muscles. Large STIM1-immunoreactive structures were found in ALS-8 patient muscle harbouring the P56S mutation in the ER protein VAPB. CONCLUSION: These findings suggest that STIM1 is involved in several ways in the reaction of muscle fibres to denervation, probably reflecting alterations in calcium homeostasis in denervated muscle fibres.

Pediatric Nodular Lymphocyte-predominant Hodgkin Lymphoma: Treatment Recommendations of the GPOH-HD Study Group.

Nodular lymphocyte-predominant Hodgkin lymphoma (nLPHL) is a very rare disease in childhood and adolescence. In Germany, about 15 newly diagnosed patients present with this disease annually; this number comprises less than 10% of all pediatric Hodgkin lymphoma cases. Since the EuroNet-PHL-LP1 trial for early stage nLPHL patients stopped recruiting in Germany in October 2014, the GPOH-HD writing committee reviewed the literature and decided to deliver treatment recommendations for childhood and adolescent nLPHL patients. These guidelines shall be applicable to young nLPHL patients in European countries that will no longer be able to participate in nLPHL trials for young patients. Therefore, the EuroNet-PHL-nLPHL-registry will be installed to provide quality assured central review of staging and response assessment for registered patients by the Central Review Board of EuroNet-PHL in Halle/Leipzig, Germany.

[Lymphadenopathy: demarcation to malignant lymphomas]. / Lymphadenopathie: Grenzziehung zu malignen Lymphomen.

Recognition of the differential diagnosis between lymphadenitis and malignant lymphoma requires good knowledge of the basic forms of the disease as well in depth knowledge of the structure of the individual compartments. There are defined forms of lymphadenitis where the differential diagnosis to certain lymphoma entities is known. Other reactive structural alterations show indistinct limits so that a decision is only possible after using additional techniques, such as immunohistochemistry and molecular analyses. Finally, there are marginal areas which can only be clarified by including clinical data.

[Round robin test for detection of genomic aberrations in non-Hodgkin lymphoma by in situ hybridization]. / Ringversuch zum Nachweis genomischer Veränderungen bei Non-Hodgkin-Lymphomen mittels In-situ-Hybridisierung.

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. RESULTS: 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. CONCLUSIONS: 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.

[Hyperthyroidism, eosinophilia, and fever in a 64-year-old patient]. / Hyperthyreose, Eosinophilie und Fieber bei einem 64-jährigen Patienten.

We report on a male patient suffering from loss of weight, fatigue, fever, eosinophilia, and hyperthyreoidism. The echocardiogram revealed a left atrial mass originating from the posterior mitral leaflet. In combination with the constitutional symptoms a left atrial myxoma was diagnosed. The tumor was surgically removed. Postoperatively therapy with corticosteroids and thiamazole was stopped. During follow-up, eosinophilia and hyperthyreodism could no longer be detected.

[Vasculitis: histopathology and differential diagnosis]. / Vaskulitis: Histopathologie und Differenzialdiagnose.

A histopathologically confirmed biopsy is the gold standard for the diagnosis of vasculitis. Possible etiologies include primary systemic vasculitis, secondary vasculitis or isolated single organ vasculitis, although on histopathological grounds alone a clear differentiation is frequently not possible. The key criteria of morphological vasculitis work-up include vessel size, type of inflammation (granulomatous, necrotizing and/or leukocytoclastic) as well as the presence or absence of immune complexes and extravascular inflammatory changes. Together with the typical organ involvement and serological data, these criteria constitute the basis of vasculitis classification. Differential diagnostic overlaps and possible discrimination methods are presented. In the same way that the clinical approach of vasculitis patients is an interdisciplinary one, histopathology can only provide a definite diagnosis in combination with clinical and serological data. A conclusive morphological diagnosis depends on the right time of biopsy and the selection of appropriate biopsy material.

Hibernoma-like brown fat in the bone marrow: report of a unique case.

We report on a bone-marrow biopsy of a 61-year-old female patient that was performed because of the clinical suspicion of a myeloproliferative disease. The trephine biopsy showed morphological features that were consistent with an essential thrombocythaemia (ET). The diagnosis of a myeloproliferative disease could be corroborated by demonstration of the V617F mutation of JAK2. Besides the histological features of ET, the marrow showed a peculiar infiltrate that consisted of multivacuolated cells that were immunohistochemically identified as brown adipose tissue with a hibernoma-like picture. To the best of our knowledge, this is the first report on brown adipose tissue in the bone marrow.

Prognostic significance of clusterin immunoreactivity in breast cancer.

Clusterin (CLU) is involved in a variety of biological processes and has been found to be expressed even in many human malignancies, including breast cancer. Currently, there are only few data on the prognostic value of CLU in breast cancer. We therefore evaluated the relationship between CLU expression and clinicopathological parameters as well as relapse-free survival (RFS) and metastasis-free survival (MFS) of 141 breast cancer patients using the monoclonal antibody 7D1. CLU expression was found in 26% of cases and correlated significantly with high histological tumor grade and high Ki-67 labeling index (p=0.026 and p=0.010, respectively). Univariate Cox regression analysis revealed that CLU expression was tendentiously associated with RFS (p=0.068; relative risk [RR]: 1.77) and MFS (p=0.122; RR: 1.57). In a multivariate analysis, tumor grade, stage, estrogen receptor status and patients age (concerning RFS) as well as grade and lymph node status (concerning MFS) were identified as significant independent prognosticators. CLU expression showed an independent prognostic relevance concerning prediction of RFS by trend (p=0.110; RR: 1.81). We conclude from our data that estimation of CLU immunoreactivity may be helpful as a supplementary criterion to better assess the tumors propensity to relapse in selected cases of breast carcinoma.

Cytogenetic characteristics of a murine in vitro model for the human anaplastic large cell lymphoma (ALCL).

Anaplastic large cell lymphoma (ALCL) is an entity of non-Hodgkin lymphomas (NHL) that often occurs in young children and adolescents. In the majority of cases, ALCL are of T-cell origin and contain the t(2;5)(p23;q35) leading to an NPM-ALK fusion or variant ALK translocations. In addition, there is an ALK-negative subtype of ALCL. The anaplastic lymphoid cell line TS1G6 established by interleukin (IL)-9 transfection of T-helper cells represents a murine model of this subtype. Here, we describe the cytogenetic features of this cell line using spectral karyotyping (SKY) and single-color fluorescence in situ hybridization (FISH). We show that TS1G6 cells exhibit a hypotetraploid karyotype with complex structural alterations. Several unbalanced translocations involved the chromosomal region 14E5, and different translocation partners, i.e. X?A6, 3A3 and 8A1. FISH analysis using a BAC clone containing c-myc confirmed the presence of six copies, but also demonstrated that two loci were irregularly located, indicating that additional intrachromosomal rearrangements had occurred. Moreover, a duplication of the region XF2 approximately 3 was identified. Furthermore, six chromosomes 15 were found, representing a trisomy 15 in a tetraploid chromosome complement, indicating an altered gene dosage of the oncogene c-myc located in region 15D3.

Similar clinical features in follicular lymphomas with and without breaks in the BCL2 locus.

Approximately 15% of follicular lymphomas (FLs) lack breaks in the BCL2 locus. The aim of this study was to better define molecular and clinical features of BCL2-breakpoint/t(14;18)-negative FLs. We studied the presence of BCL2, BCL6 and MYC breaks by fluorescence in situ hybridization and the expression of BCL2, MUM1, CD10, P53 and Ki67 in large clinical trial cohorts of 540 advanced-stage FL cases and 116 early-stage disease FL patients treated with chemotherapy regimens and radiation, respectively. A total of 86% and 53% of advanced- and early-stage FLs were BCL2-breakpoint-positive, respectively. BCL2 was expressed in almost all FLs with BCL2 break and also in 86% and 69% of BCL2-breakpoint-negative advanced- and early-stage FLs, respectively. CD10 expression was significantly reduced in BCL2-breakpoint-negative FLs of all stages and MUM1 and Ki67 expression were significantly increased in BCL2-break-negative early-stage FLs. Patient characteristics did not differ between FLs with and without BCL2 breaks and neither did survival times in advanced-stage FLs. These results suggest that the molecular profile differs to some extent between FLs with and without BCL2 breaks and support the notion that FLs with and without BCL2 breaks belong to the same lymphoma entity.

Cytogenetic findings and results of combined immunophenotyping and karyotyping in Hodgkin's disease.

Cytogenetic studies were performed in 21 cases of Hodgkin's disease. Fourteen cases revealed chromosomally aberrant clones which could be fully described in 12 cases. Two cases showed different unrelated clones and five cases only single cell aberrations. Recurrent breakpoints were 1p13/21 (six cases), 7q32/34 (five cases), 2p16/21 and 19p13 (four cases each), 4q25/28, 6q15/21 and 12q22/23 (three cases each). In two cases, a translocation between band 19q13 and band 14q11 or 14q32 was found. This finding may indicate that an unknown oncogene in 19p13 is activated by juxtaposition next to a T-cell receptor or immunoglobulin gene in 14q11 or 14q32, respectively. In eight cases each, total or partial monosomy 4 or 6 was present suggesting that tumor suppressor genes in 4q or 6q play a role in tumor development in Hodgkin's disease. Moreover, the aberrant clones lacked the Y-chromosome in men and the second X-chromosome in women in eight out of nine and in two out of three cases, respectively. Although different cell populations, especially T cells, showed mitotic activity in unstimulated short term culture, combined immunophenotyping and karyotyping unequivocally demonstrated that CD30 and CD15 positive Hodgkin and Sternberg-Reed cells represented the chromosomally aberrant clones.

Different biological risk factors in young poor-prognosis and elderly patients with diffuse large B-cell lymphoma.

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 overexpression of MYC and BCL2 showed only limited association with inferior OS. All immunohistochemical cell of origin 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 with an elderly population, with BCL2 translocations emerging as a powerful negative prognostic marker.

T-cell receptor and immunoglobulin gene rearrangements in cutaneous T-cell-rich pseudolymphomas.

T-cell rich, small lymphoid infiltrates of the skin may cause considerable problems in the differential diagnosis of reactive versus neoplastic lymphoproliferations, particularly when they lack the morphologic and immunophenotypical criteria for a malignant lymphoma. We did histologic, immunohistologic, and gene rearrangement studies on 10 biopsies from patients with persistent nodular T-cell-rich skin lesions refractory to topical therapy. Based on clinical and immunohistochemical findings, no discrimination was possible between reactive lesions and malignant lymphoproliferations. Histologically, most of the cases contained T-lymphocytic infiltrations that were assumed to be reactive; however, in four biopsies a neoplastic infiltration could not be excluded. Although the T-cell receptor (TCR) beta chain and the immunoglobulin heavy chain (IgH) genes were in germ-line configuration in nine of 10 cases, indicating a predominantly polyclonal lymphocellular infiltrate, in one patient without clinical evidence of malignant lymphoma at presentation a clonally rearranged TCR beta chain gene with the IgH gene in germ-line configuration was detected. One year later, the patient developed a cutaneous pleomorphic T-cell lymphoma and subsequently a large cell anaplastic (CD30+) T-cell lymphoma in an inguinal lymph node. We conclude that clonal T-cell proliferations can be detected by molecular genetic analysis of T-cell-rich, small lymphoid infiltrates of the skin. This finding may precede development of an overt malignant T-cell lymphoma.

Simultaneous enzyme-immunocytochemical detection of antigens in monocellular specimens with monoclonal antibodies.

An immunoperoxidase and immunoalkaline phosphatase technique is described specially devised for separate cell specimens such as smears, cytospins, and tissue imprints. The reaction may be used alone or in combination for simultaneous staining with 2 different monoclonal antibodies. Monoclonal antibodies Leu3a, Leu2a, T4, T8, anti-kappa, and anti-lambda light chain were used in combination to visualize subsets of human lymphocytes selectively. Six cases of chronic lymphocytic leukemia were classified by this method.

Colonic primary large cell lymphoma with marginal zone growth pattern presenting as multiple polyps.

We report a rare case of primary gastrointestinal lymphoma, stage IE, in a 58-year-old white man who had multiple colonic polyps measuring up to 1 x 1.1 cm. The tumor originated in the marginal zone of the follicles infiltrating the interfollicular spaces. Follicular colonization was frequently seen. The mucosa was spared by the infiltrate. Morphologically, the neoplastic cells were monomorph, intermediate-sized blasts. Rare small to intermediate sized cells, some with centrocyte-like morphology, intermingled the blastic infiltrate. The neoplastic cells expressed CD20 and had a monotypic immunoglobulin of cytoplasmic IgM (kappa) on paraffin sections. Tumor cells stained negative for CD45RO, CD5, CD10, IgD, and CD23. Polymerase chain reaction revealed a clonal V-D-J rearrangement. Bcl-1 and bcl-2 rearrangement were not detected. We therefore suggest the diagnosis of primary large cell lymphoma with marginal zone growth pattern mimicking colonic adenomas.

Efficacy of histologic criteria for diagnosing early mycosis fungoides: an EORTC cutaneous lymphoma study group investigation. European Organization for Research and Treatment of Cancer.

The correct classification of lymphoproliferative disorders provides valuable information regarding subsequent clinical evolution of the disease. The ability of pathologists to distinguish such lesions is generally low, especially when dealing with minimal lymphoid infiltrates. To improve the efficacy of histopathology in the diagnosis of early lesions of mycosis fungoides (MF), we reviewed 24 skin biopsies from 18 patients with patch stage lesions of MF early in the course of their disease and 13 slides of lichenoid, spongiotic, or psoriasiform simulators of MF as a control series. A series of cytoarchitectural features was assessed, and differences in the distribution of histopathologic parameters between the two groups (early MF lesions and MF simulators) were evaluated by the chi-square test and Fisher's exact test. For these parameters, sensitivity and specificity also were calculated. A multivariate log-linear analysis was performed to estimate which of the morphologic parameters yielded independent diagnostic information. We found that the most important feature for the diagnosis of lymphoma was the presence of lymphocytes with extremely convoluted, medium-large (7-9 microm in diameter) nuclei (medium-large cerebriform cells), singly or clustered in the epidermis and in small sheets in the dermis. Additional significant histologic features were epidermotropism as single cells lined up along the basal keratinocytes of the dermal-epidermal junction, absence of significant papillary dermis fibrosis, and absence of significant numbers of dermal blastlike cells. We conclude that the efficacy of single histopathologic features in the diagnosis of early MF is generally poor. Only the presence of medium-large cerebriform cells in the epidermis or in clusters in the dermis proved to be a highly reliable feature. However, the histopathologic diagnosis of early MF lesions and their discrimination from inflammatory simulators can be achieved using the constellation of cytoarchitectural parameters proposed.

The distribution of non-Hodgkin's lymphoma in the lymphoid compartments of the human spleen.

In a series of 139 spleens involved by non-Hodgkin's lymphoma, we found that each type of lymphoma (as classified according to the Kiel classification) has a specific pattern of infiltration in the red and white pulp. Tumor infiltration in preexistent follicles was not a feature of B-cell lymphomas, but tumor nodules were found in the red pulp nonfiltering areas in cases of immunocytoma (small lymphocytic plasmacytoid) and centroblastic-centrocytic lymphoma (follicle center-cell lymphoma). B-chronic lymphocytic leukemia and centrocytic-centroblastic lymphoma were located along central arteries of T-cell areas. T-cell areas were infiltrated by B-prolymphocytic leukemia, immunocytoma, centrocytic lymphoma (lymphocytic lymphoma of intermediate differentiation), and T-cell lymphoma/leukemia. The red pulp showed diffuse involvement in leukemic cases. Additionally, there was pericapillary growth in all cases of low-grade B-cell lymphoma. The findings, which are related to the physiological counterparts of the lymphoma cells, contribute to our knowledge of the routes of circulation as well as the homing areas of lymphocytes in the human spleen.

Polymorphous high-grade B cell lymphoma is the predominant type of spontaneous primary cerebral malignant lymphomas. Histological and immunomorphological evaluation of computed tomography-guided stereotactic brain biopsies.

In this retrospective study, a series of 54 patients (1982-1989) with sporadic primary cerebral malignant lymphomas is presented. All diagnoses were uniformly done on computed tomography-guided stereotactic brain biopsies according to histological criteria and immunomorphological data. In this series, the tumors were predominantly (25 of 48; 52%) classified as polymorphous high-grade blastic B cell lymphomas. This lymphoma type is therefore regarded as the most common type of sporadic primary cerebral non-Hodgkin's lymphoma. Severe regression (++/ ), which may dramatically alter the morphological appearance of a brain lymphoma, was found in 24 of 28 (86%) of cases with glucocorticoid administration prior to stereotactic brain biopsy.