Anti-ALK Antibodies in Patients with ALK-Positive Malignancies Not Expressing NPM-ALK.

Patients with Nucleophosmin (NPM)- Anaplastic Lymphoma Kinase (ALK) fusion positive Anaplastic Large Cell Lymphoma produce autoantibodies against ALK indicative of an immune response against epitopes of the chimeric fusion protein. We asked whether ALK-expression in other malignancies induces specific antibodies. Antibodies against ALK were detected in sera of one of 50 analysed ALK-expressing neuroblastoma patients, 13 of 21 ALK positive non-small cell lung carcinoma (NSCLC) patients, 13 of 22 ALK translocation-positive, but NPM-ALK-negative lymphoma patients and one of one ALK-positive rhabdomyosarcoma patient, but not in 20 healthy adults. These data suggest that boosting a pre-existent anti-ALK immune response may be more feasible for patients with ALK-positive NSCLC, lymphomas and rhabdomyosarcomas than for tumours expressing wild-type ALK.This work was supported by a grant from the Deutsche Jose Carreras Leukämie-Stiftung (DJCLS08/ 09) to WW, and RS. CDW and WW are additionally supported by the von behring röntgen stiftung (60-0011) and the Forschungshilfe Peiper, IO and RS by the Kinderkrebsinitiative Buchholz/HolmSeppensen and KP by Bloodwise, the Julian Starmer-Smith Memorial Fund and the Sam Foye Fund. SDT is a Bloodwise University Senior Lecturer and is also supported by the Alex Hulme Foundation and the Sam Foye Fund. MH is supported by a PhD studentship from the Wellcome Trust.This is the final version of the article. It first appeared from Ivyspring International via http://dx.doi.org/10.7150/jca.1523

A unifying hypothesis for PNMZL and PTFL: morphological variants with a common molecular profile

Pediatric nodal marginal zone lymphoma (PNMZL) is an uncommon B-cell neoplasm affecting mainly male children and young adults. This indolent lymphoma has distinct characteristics that differ from those of conventional nodal marginal zone lymphoma (NMZL). Clinically, it exhibits overlapping features with pediatric-type follicular lymphoma (PTFL). To explore the differences between PNMZL and adult NMZL and its relationship to PTFL, a series of 45 PNMZL cases were characterized morphologically and genetically by using an integrated approach; this approach included whole-exome sequencing in a subset of cases, targeted next-generation sequencing, and copy number and DNA methylation arrays. Fourteen cases (31%) were diagnosed as PNMZL, and 31 cases (69%) showed overlapping histologic features between PNMZL and PTFL, including a minor component of residual serpiginous germinal centers reminiscent of PTFL and a dominant interfollicular B-cell component characteristic of PNMZL. All cases displayed low genomic complexity (1.2 alterations per case) with recurrent 1p36/TNFRSF14 copy number-neutral loss of heterozygosity alterations and copy number loss (11%). Similar to PTFL, the most frequently mutated genes in PNMZL were MAP2K1 (42%), TNFRSF14 (36%), and IRF8 (34%). DNA methylation analysis revealed no major differences between PTFL and PNMZL. Genetic alterations typically seen in conventional NMZL were absent in PNMZL. In summary, overlapping clinical, morphologic, and molecular findings (including low genetic complexity; recurrent alterations in MAP2K1, TNFRSF14, and IRF8; and similar methylation profiles) indicate that PNMZL and PTFL are likely part of a single disease with variation in the histologic spectrum. The term "pediatric-type follicular lymphoma with and without marginal zone differentiation" is suggested.Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved

Mantle cell lymphomas with concomitant MYC and CCND1 breakpoints are recurrently TdT positive and frequently show high-grade pathological and genetic features

Chromosomal breakpoints involving the MYC gene locus, frequently referred to as MYC rearrangements (MYC - R+), are a diagnostic hallmark of Burkitt lymphoma and recurrent in many other subtypes of B-cell lymphomas including follicular lymphoma, diffuse large B-cell lymphoma and other high-grade B-cell lymphomas and are associated with an aggressive clinical course. In remarkable contrast, in MCL, only few MYC - R+ cases have yet been described. In the current study, we have retrospectively analysed 16 samples (MYC - R+, n = 15, MYC - R-, n = 1) from 13 patients and describe their morphological, immunophenotypic and (molecular) genetic features and clonal evolution patterns. Thirteen out of fifteen MYC - R+ samples showed a non-classical cytology including pleomorphic (centroblastic, immunoblastic), anaplastic or blastoid. MYC translocation partners were IG-loci in 4/11 and non-IG loci in 7/11 analysed cases. The involved IG-loci included IGH in 3 cases and IGL in one case. PAX5 was the non-IG partner in 2/7 patients. The MYC - R+ MCL reported herein frequently displayed characteristics associated with an aggressive clinical course including high genomic-complexity (6/7 samples), frequent deletions involving the CDKN2A locus (7/10 samples), high Ki-67 proliferation index (12/13 samples) and frequent P53 expression (13/13 samples). Of note, in 4/14 samples, SOX11 was not or only focally expressed and 3/13 samples showed focal or diffuse TdT-positivity presenting a diagnostic challenge as these features could point to a differential diagnosis of diffuse large B-cell lymphoma and/or lymphoblastic lymphoma/leukaemia

Clinical relevance of molecular characteristics in Burkitt lymphoma differs according to age

While survival has improved for Burkitt lymphoma patients, potential differences in outcome between pediatric and adult patients remain unclear. In both age groups, survival remains poor at relapse. Therefore, we conducted a comparative study in a large pediatric cohort, including 191 cases and 97 samples from adults. While TP53 and CCND3 mutation frequencies are not age related, samples from pediatric patients showed a higher frequency of mutations in ID3, DDX3X, ARID1A and SMARCA4, while several genes such as BCL2 and YY1AP1 are almost exclusively mutated in adult patients. An unbiased analysis reveals a transition of the mutational profile between 25 and 40 years of age. Survival analysis in the pediatric cohort confirms that TP53 mutations are significantly associated with higher incidence of relapse (25 ± 4% versus 6 ± 2%, p-value 0.0002). This identifies a promising molecular marker for relapse incidence in pediatric BL which will be used in future clinical trials

Ki-67 as a prognostic marker in mantle cell lymphoma—consensus guidelines of the pathology panel of the European MCL Network

Mantle cell lymphoma (MCL) has a heterogeneous clinical course and is mainly an aggressive B cell non-Hodgkin lymphoma; however, there are some indolent cases The Ki-67 index, defined by the percentage of Ki-67-positive lymphoma cells on histopathological slides, has been shown to be a very powerful prognostic biomarker. The pathology panel of the European MCL Network evaluated methods to assess the Ki-67 index including stringent counting, digital image analysis, and estimation by eyeballing. Counting of 2 × 500 lymphoma cells is the gold standard to assess the Ki-67 index since this value has been shown to predict survival in prospective randomized trials of the European MCL Network. Estimation by eyeballing and digital image analysis showed a poor concordance with the gold standard (concordance correlation coefficients [CCC] between 0.29 and 0.61 for eyeballing and CCC of 0.24 and 0.37 for two methods of digital image analysis, respectively). Counting a reduced number of lymphoma cells (2 × 100 cells) showed high interobserver agreement (CCC = 0.74). Pitfalls of the Ki-67 index are discussed and guidelines and recommendations for assessing the Ki-67 index in MCL are given

Correction. "The 5th edition of The World Health Organization Classification of Haematolymphoid Tumours: Lymphoid Neoplasms" Leukemia. 2022 Jul;36(7):1720-1748

We herein present an overview of the upcoming 5th edition of the World Health Organization Classification of Haematolymphoid Tumours focussing on lymphoid neoplasms. Myeloid and histiocytic neoplasms will be presented in a separate accompanying article. Besides listing the entities of the classification, we highlight and explain changes from the revised 4th edition. These include reorganization of entities by a hierarchical system as is adopted throughout the 5th edition of the WHO classification of tumours of all organ systems, modification of nomenclature for some entities, revision of diagnostic criteria or subtypes, deletion of certain entities, and introduction of new entities, as well as inclusion of tumour-like lesions, mesenchymal lesions specific to lymph node and spleen, and germline predisposition syndromes associated with the lymphoid neoplasms

2009

ABSTRACT © F e r r a t a S t o r t i F o u n d a t i o n N o c o m m e r c i a l u s e software (Biodiscovery, El Segundo, CA, USA). Gains and losses were evaluated by 2 different observers. Fluorescence in situ hybridization (FISH) analyses were performed for the detection of breakpoints or gene fusions and for verification of gains in chromosome 6p25 as previously described. Potential point mutations detected by MIP-assay in PIK3CA, FBXW7, ABL1, NOTCH1, STK11 and PTEN were also analyzed by direct sequencing using ABI PRISM 3100 Genetic Analyzer system (Applied Biosystems, Foster City, CA, USA). Details are described in the Online Supplementary Appendix. Similarly, the coding exons of TNFRSF14 (Online Clonality analysis was performed investigating the framework 1-3 regions of the immunoglobulin heavy chain (IGH) according to the Biomed-2 protocol. 11 Statistical analyses were performed using PASW Statistics software version 18 (SPSS Inc., Chicago, IL, USA). The study was performed in the framework of the BFM-NHL trial, for which central and local institutional review board (IRB) approvals were obtained, and according to the guidelines of the MMML Network Project of the Deutsche Krebshilfe (approved by the Institutional Review Board of the Medical Faculty Kiel under 403/05). Results and Discussion Pediatric FL is a rare disease that differs from its adult counterpart both genetically and clinically. 1238 haematologica | 2013; 98(8) Germline homozygosity (e.g. AA, BB alleles) at a given SNP results in calls at the 0 and 1 levels, respectively, germline heterozygosity (AB-alleles) in calls around 0.5 (y-Axis: 0-1). CNN-LOH in the tumor leads to loss of calls around 0.5 and to the presence of allelic imbalance calls derived from a sum of heterozygous normal cell (AB) and homozygous tumor cell (AA or BB) calls for a given locus resulting in values between 0-0.5 or 0.5-1 depending on the amount of cells carrying the aberration. Thus, in the areas with only contribution from one parent (LOH/CNN-LOH), two bands should we expected (0% and 100%->0 and 1.0. y Axis). In the 3 cases (pFL7, pFL10, pFL14), the probes did not reach such thresholds because alterations are detected to be in mosaicism (not germline alterations .4 In the present study, we determined genetic aberrations in a series of 18 pediatric FL cases lacking such IRF4 translocation. Of these 18 FL, 9 (50%) were classified as FL grade 3a (FL3a), 6 (33%) as grade 3b (FL3b), one (6%) as grade 3 unclassified, and 2 (11%) as grade 2. Areas of grade 1 or 2 FL as a second lymphoma component were detectable in 4 cases diagnosed as FL3a (22%), while a simultaneous diffuse large B-cell lymphoma (DLBCL) component was noted in 4 (22%) cases, 3 diagnosed as FL3b and one as FL3a. Seven patients presented with stage I disease, 5 were rated as stage II and 3 suffered from stage III disease. Tumor localization in or dissemination to the neck region was the most frequent presentation (11 of 18). Notably, the present series of pediatric FL seems to differ from those of other recently published series with regard to sites of involvement, clinical stage and presence of a DLBCL component. CN determination by aCGH and/or MIP-assay was successful in 16 of the 18 FL (89%) (Online Supplementary Both the gain in 6p as well as CNN-LOH/loss of 1p seem not to be exclusive to pediatric FL, since they have also been described in adult FL independently of the presence of t(14;18) translocation. 14 In fact, deletions and CNN-LOH of 1p36 have been described as one of the most frequent secondary genetic aberrations in adult FL A synopsis of the obtained molecular profiling results revealed that all cases with breaks in IGH or BCL6 also showed CN alterations and/or mutations in TNFRSF14 or EZH2 genes. Based on the results of the molecular analyses, two groups of FL could be distinguished: one containing the genetically aberrant pediatric FL and another one comprising the pediatric FL without any aberration ( Studying IGH clonality revealed that the 2 samples with polyclonal pattern (pFL2 and pFL11) were in the set lacking genomic aberrations. In one of the cases (pFL2), only the FR3 region was evaluable in the central IGH clonality analysis. Therefore, we cannot exclude that clonality could be detectable with FR1 or FR2 primers. Despite the polyclonal pattern, both cases displayed clear histomorphological features of malignancy with subtotal effacement of the underlying lymphnode structure, destruction of the normal germinal center architecture, loss of follicle mantles and abnormaly enlarged in part confluent neoplastic follicles. Although there is general agreement regarding the absence of BCL2-rearrangement in pediatric FL at the molecular level, reported levels of BCL2 protein expression vary considerably ranging from 0% to 50%. Comparing the two groups defined by the genomic aberration status with clinical data, the group with aberrations was enriched for patients showing higher grade histology and higher stage disease patterns. For example, advanced disease stage (>II), grade 3b or a DLBCL component occurred almost exclusively in the genetically altered group In summary, we describe the pattern of genomic imbalances in IRF4 translocation negative pediatric FL and identify recurrent mutation of TNFRSF14. Moreover, we show genetic alterations to distinguish two subsets of pediatric FL. In the first subset genomic aberrations could be identified with the techniques applied and this subset is associated with higher grade and/or diffuse large B-cell lymphoma component and more widespread disease. The second group lacks genetic alterations detectable with the present approaches and is associated with a more limited disease. Despite the absence of genomic aberrations, these I. Martin-Guerrero et al. 1240 haematologica | 2013; 98(8) Given that the patients included in this study have been treated independently of the genomic aberration status and show excellent survival rates, we cannot, therefore, comment on whether the detectability or pattern of genomic differences also translate into a different clinical outcome or whether the genetically normal appearing FL might be treated less intensively or if a "watch and wait" approach can be adopted in completely resected local disease. Acknowledgment

Co-Occurrence of EBV-Positive Mucocutaneous Ulcer (EBV-MCU) and CLL/SLL in the Head and Neck Region

EBV-positive mucocutaneous ulcer (EBV-MCU) was classified as a rare new entity of the lymphoproliferative B-cell diseases by the WHO in 2017 and must be distinguished from head and neck squamous cell carcinoma by early biopsy. The aim of the study is to raise awareness of the disease and to give a review of the current literature and a recommendation for EBV-MCU management. All EBV-MCU cases of the head and neck region published so far were included. We also report a case of a pharyngeal EBV-MCU in an 89-year-old patient who was immunosuppressed by chronic lymphatic leukaemia/small lymphocytic lymphoma (CLL/SLL). In contrast to all previously described cases, histopathology showed a co-infiltration of EBV-MCU and CLL/SLL. A total of 181 cases were identified on PubMed and summarised. EBV-MCU was predominantly caused by immunosuppressive drug therapy. Complete remission could be achieved in 68% of cases and was mainly attributed to a reduction of the immunosuppressive therapy alone (72%). However, some severe cases require more aggressive treatment. Regarding the various histopathologic similarities to other lymphoproliferative disorders, the diagnosis of EBV-MCU can be misleading, with a great impact on patient care and treatment. This diagnosis must be made with caution and requires a combination of clinical, morphological and immunophenotypic features