Liquid biopsy for the identification of intravascular large B-cell lymphoma

Spheroid culture to select theoretical therapeutic drugs in intravascular large B-cell lymphoma

Intravascular large B-cell lymphoma (IVLBCL) is a rare type of extranodal large B-cell lymphoma that is characterized by the proliferation of lymphoma cells in the lumina of small vessels. Recent progress uncovering the genetic characteristics associated with MYD88/CD79B mutations has stimulated interest in the use of drugs targeting B-cell receptor signaling, including Bruton's tyrosine kinase. However, difficulties in culturing ex vivo IVLBCL cells has hampered research on the development of novel therapies. In the present study, we demonstrated the establishment of an ex vivo culture system of IVLBCL cells obtained from patient-derived xenograft (PDX) models. The spheroid culture enabled us to culture IVLBCL PDX cells for more than 10 days and to explore the efficacy of drug treatments acting on these cells. We found that carfilzomib and ibrutinib were effective for treating IVLBCL in ex vivo experiments and conducted in vivo analyses to assess the efficacy of these drugs. Although the efficacy of carfilzomib was difficult to confirm due to its toxicity in our models, ibrutinib showed comparable efficacy to a standard combination of chemotherapy drugs. Together, our data provide a new culture method for IVLBCL PDX cells and a rationale for translating ibrutinib to clinical use in IVLBCL patients.

Successful treatment of hemophagocytic intravascular large B-cell lymphoma with CNS involvement with BTK inhibitor combined with rituximab and high-dose methotrexate

This is a case of hemophagocytic intravascular large B-cell lymphoma (IVLBCL) with central nervous system (CNS) involvement. Although R-CHOP chemotherapy regimen has been shown significant improvement in survival rate. The prognosis and outcomes remain unsatisfactory, which is identified as outstanding challenges and need solutions. Gene and molecular profiling studies may provide new therapeutic strategies, especially the BCR/TLR/IL-1R/NF-κB signaling pathway in IVLBCL. Here, we treated the hemophagocytic IVLBCL CNS-involved patient with the Bruton tyrosine kinase inhibitor (BTKi) to block NF-κB pathway, and indicated that the second-generation BTKi zanubrutinib-based treatment was feasible and efficient.

Plasma circulating tumour DNA is a better source for diagnosis and mutational analysis of IVLBCL than tissue DNA

Diagnosis of intravascular large B-cell lymphoma (IVLBCL) is a challenge due to its heterogeneous clinical presentation and lack of specific markers. This retrospective study investigated the utility of circulating tumour DNA (ctDNA) sequencing for diagnosing IVLBCL and analysing its mutation landscape. A cohort of 34 IVLBCL patients enrolled and underwent plasma ctDNA targeted sequencing. The median plasma ctDNA concentration was 135.0 ng/mL, significantly higher than that in diffuse large B-cell lymphoma (DLBCL) controls. Correlations were found between ctDNA concentration and disease severity indicators, LDH and SF. Mutation analysis revealed frequent mutations in B-cell receptor and NF-κB signalling pathways, including MYD88 (56%), CD79B (44%), TNFAIP3 (38%) and IRF4 (29%). CNS involvement was significantly related with BCL6 and CD58 mutation. Patients with complicated hemophagocytic lymphohistiocytosis had significantly higher mutation rates in B2M. Comparison with DLBCL subtypes showed distinctive mutation profiles in IVLBCL. Moreover, plasma ctDNA detected more mutations with higher variant allele fraction than tissue DNA, suggesting its superiority in sensitivity and accessibility. Dynamic monitoring of ctDNA during treatment correlated with therapeutic responses. This study revealed the role of ctDNA in IVLBCL diagnosis, mutation analysis, and treatment monitoring, offering a promising avenue for improving patient diagnosis in this rare lymphoma subtype.

Insulin-like Growth Factor II mRNA-binding Protein 3 is a Highly Sensitive Marker for Intravascular Large B-cell Lymphoma: Immunohistochemical Analysis of 152 Pathology Specimens From 88 Patients

Intravascular large B-cell lymphoma (IVLBCL) is a rare type of aggressive extranodal large B-cell lymphoma characterized by the selective growth of lymphoma cells within the lumina of blood vessels, particularly capillaries. IVLBCL lacks mass formation, and its diagnosis can be challenging. We analyzed the utility of insulin-like growth factor II mRNA-binding protein 3 (IMP3) immunohistochemistry for IVLBCL diagnosis in various organs. Double staining with paired box 5 (PAX5) was performed for validation. Overall, 152 pathological specimens (111 positive and 41 negative for IVLBCL) obtained from 88 patients with a diagnosis of IVLBCL were stained for IMP3 and IMP3/PAX5. As negative controls, 40 pathology specimens from 38 patients with no history of IVLBCL or other B-cell lymphomas were stained for IMP3, which comprised 31 benign pathological specimens from 29 patients in whom malignancy was suspected, 7 cases of appendicitis with intravascular and/or intralymphatic lymphoid proliferations, and 2 cases of intravascular natural killer/T-cell lymphoma. All mononuclear cells with cytoplasmic staining were considered positive for IMP3 expression, but expression restricted to germinal center B cells was excluded from evaluation. All 111 IVLBCL pathological specimens were positive for IMP3 and IMP3/PAX5. In addition, 11 of the 41 specimens originally diagnosed as IVLBCL-negative showed IMP3/PAX5 double-positive cells, raising the suspicion of IVLBCL. However, of the 40 negative control samples, IMP3-positive non-germinal center B cells were detected in only 2 samples ( P = 0.0131) and no intravascular IMP3-positive B cells suspicious for IVLBCL were identified. Altogether, IMP3 immunohistochemistry is a highly sensitive marker of IVLBCL and can be a helpful adjunct for IVLBCL diagnosis.

EBV-Positive Intravascular Large B-Cell Lymphoma of the Small Intestine: A Case Report and Literature Review

Intravascular large B-cell lymphoma (IVLBCL) is a rare lymphoma that affects the brain, skin, and bone marrow. We describe the case of a 75-year-old man who was admitted to the hospital after 4 h of stomach aches. A thorough physical examination indicated stomach discomfort and skin discoloration. Laboratory tests revealed thrombocytopenia and elevated lactate dehydrogenase levels. A computed tomography scan of the abdomen revealed that the small intestine wall was thickened, edematous, and necrotic. The necrotic small bowel was surgically removed, revealing many little round, homogenous, and unusual cells in the mesenteric vein. In-situ hybridization revealed that these cells were positive for PAX5, CD20, CD79a, CD10, and BCL2, as well as Epstein-Barr virus-encoded small RNA. After 1 week of hospitalization without treatment, the patient was diagnosed with IVLBCL and died of multiple organ dysfunction syndrome. IVLBCL is a rare illness that affects the small intestine and possibly the gastrointestinal system. It has an insidious start, a fast development, and a dismal prognosis. Knowing its clinicopathologic traits helps in understanding the illness, making an early diagnosis, and preventing rapid worsening.

Cutaneous Intravascular Hematolymphoid Entities: A Review

Intravascular lymphomas are rare disease conditions that exhibit neoplastic lymphoid cells that are confined mainly to the lumens of small capillaries and medium-sized vessels. The majority of the intravascular lymphomas are of B-cell origin, but they can include NK/T-cell and CD30+ immunophenotypes. In the histologic differential diagnosis are benign proliferations such as intralymphatic histiocytosis and intravascular atypical CD30+ T-cell proliferation. In this review, we discuss the clinical, histopathologic, and molecular findings of intravascular B-cell lymphoma, intravascular NK/T-cell lymphoma, intralymphatic histiocytosis, and benign atypical intravascular CD30+ T-cell proliferation.

Whole-exome sequencing is feasible on a fresh-frozen skin sample of intravascular large B cell lymphoma

Intravascular large B-cell lymphoma (IVLBCL) is a rare aggressive extranodal non-Hodgkin lymphoma. The predominant, if not exclusive, growth of neoplastic cells within the lumina of small-sized vessels represents the hallmark of the disease. Diagnosis is challenging due to the absence of marked lymphadenopathy, the highly heterogeneous clinical presentation, and the rarity of the condition. Clinical presentation is characterized by variable combinations of nonspecific signs and symptoms (such as fever and weight loss), organ-specific focal manifestations due to altered perfusion, and hemophagocytic syndrome. The rarity of this entity and the paucity of neoplastic cells in biopsy samples hamper the study of recurrent molecular abnormalities. The purpose of this study was to explore the feasibility of a different approach to recover a sufficient amount of DNA of acceptable quality to perform next-generation sequencing studies. Here, we report the findings of whole-exome next-generation sequencing performed on a fresh-frozen cutaneous sample of IVLBCL, paired with the patient saliva used as germline DNA. To increase the cancer cell fraction, only the subcutaneous tissue was selected. With this approach, we obtained high-quality DNA and were able to identify oncogenic mutations specific for this entity and recapitulating its post-germinal center origin, even if the tumor fraction was low. Molecular studies performed on fresh-frozen cutaneous sample are feasible in IVLBCL, especially when analysis is restricted to the subcutaneous tissue. Wide adoption of this reproducible and cost-effective approach may foster further studies, which may be of help in supporting diagnosis, providing pathogenetic insights, and guiding treatment decisions.

Utility of cerebrospinal fluid liquid biopsy in distinguishing CNS lymphoma from cerebrospinal infectious/demyelinating diseases

BACKGROUND

Distinguishing between central nervous system lymphoma (CNSL) and CNS infectious and/or demyelinating diseases, although clinically important, is sometimes difficult even using imaging strategies and conventional cerebrospinal fluid (CSF) analyses. To determine whether detection of genetic mutations enables differentiation between these diseases and the early detection of CNSL, we performed mutational analysis using CSF liquid biopsy technique.

METHODS

In this study, we extracted cell-free DNA from the CSF (CSF-cfDNA) of CNSL (N = 10), CNS infectious disease (N = 10), and demyelinating disease (N = 10) patients, and performed quantitative mutational analysis by droplet-digital PCR. Conventional analyses were also performed using peripheral blood and CSF to confirm the characteristics of each disease.

RESULTS

Blood hemoglobin and albumin levels were significantly lower in CNSL than CNS infectious and demyelinating diseases, CSF cell counts were significantly higher in infectious diseases than CNSL and demyelinating diseases, and CSF-cfDNA concentrations were significantly higher in infectious diseases than CNSL and demyelinating diseases. Mutation analysis using CSF-cfDNA detected MYD88L265P and CD79Y196 mutations in 60% of CNSLs each, with either mutation detected in 80% of cases. Mutual existence of both mutations was identified in 40% of cases. These mutations were not detected in either infectious or demyelinating diseases, and the sensitivity and specificity of detecting either MYD88/CD79B mutations in CNSL were 80% and 100%, respectively. In the four cases biopsied, the median time from collecting CSF with the detected mutations to definitive diagnosis by conventional methods was 22.5 days (range, 18-93 days).

CONCLUSIONS

These results suggest that mutation analysis using CSF-cfDNA might be useful for differentiating CNSL from CNS infectious/demyelinating diseases and for early detection of CNSL, even in cases where brain biopsy is difficult to perform.

Large B-Cell Lymphomas in the 5th Edition of the WHO-Classification of Haematolymphoid Neoplasms-Updated Classification and New Concepts

The family/class of the large B-cell lymphomas (LBCL) in the 5th edition of the World Health Organization (WHO) classification of haematolymphoid tumors (WHO-HAEM5) features only a few major changes as compared to the 4th edition. In most entities, there are only subtle changes, many of them only representing some minor modifications in diagnostic terms. Major changes have been made in the diffuse large B-cell lymphomas (DLBCL)/high-grade B-cell lymphomas (HGBL) associated with MYC and BCL2 and/or BCL6 rearrangements. This category now consists of MYC and BCL2 rearranged cases exclusively, while the MYC/BCL6 double hit lymphomas now constitute genetic subtypes of DLBCL, not otherwise specified (NOS) or of HGBL, NOS. Other major changes are the conceptual merger of lymphomas arising in immune-privileged sites and the description of LBCL arising in the setting of immune dysregulation/deficiency. In addition, novel findings concerning underlying biological mechanisms in the pathogenesis of the different entities are provided.

Cardiac Tamponade as a Recurrence of Angioimmunoblastic T-Cell Lymphoma with the Detection of a p.Gly17Val RHOA Mutation in the Pericardial Effusion

Angioimmunoblastic T-cell lymphoma (AITL) is an intractable type of T-cell lymphoma. We and others have identified that the p.Gly17Val RHOA mutation is specifically identified in AITL. We herein report a patient whose condition deteriorated, resulting from massive pericardial effusion one month after undergoing autologous transplantation for AITL. He was diagnosed with cardiac tamponade caused by AITL recurrence in the presence of the p.Gly17Val RHOA mutation as well as T-lineage cells with an aberrant immune-phenotype in the pericardial effusion. This case suggests that a precision medicine approach by detecting the presence of a p.Gly17Val RHOA mutation is useful for the management of AITL.

Intravascular Large B-Cell Lymphoma Genomic Profile Is Characterized by Alterations in Genes Regulating NF-κB and Immune Checkpoints

Intravascular large B-cell lymphoma (IVLBCL) is an uncommon lymphoma with an aggressive clinical course characterized by selective growth of tumor cells within the vessels. Its pathogenesis is still uncertain and there is little information on the underlying genomic alterations. In this study, we performed a clinicopathologic and next-generation sequencing analysis of 15 cases of IVLBCL using a custom panel for the detection of alterations in 68 recurrently mutated genes in B-cell lymphomagenesis. Six patients had evidence of hemophagocytic syndrome. Four patients presented concomitantly a solid malignancy. Tumor cells outside the vessels were observed in 7 cases, 2 with an overt diffuse large B-cell cell lymphoma. In 4 samples, tumor cells infiltrated lymphatic vessel in addition to blood capillaries. Programmed death-ligand 1 (PD-L1) was positive in tumor cells in 4 of 11 evaluable samples and in macrophages intermingled with tumor cells in 8. PD-L1 copy number gains were identified in a higher proportion of cases expressing PD-L1 than in negative tumors. The most frequently mutated gene was PIM1 (9/15, 60%), followed by MYD88L265P and CD79B (8/15, 53% each). In 6 cases, MYD88L265P and CD79B mutations were detected concomitantly. We also identified recurrent mutations in IRF4 , TMEM30A , BTG2 , and ETV6 loci (4/15, 27% each) and novel driver mutations in NOTCH2 , CCND3 , and GNA13 , and an IRF4 translocation in 1 case each. The mutational profile was similar in patients with and without evidence of hemophagocytic syndrome and in cases with or without dissemination of tumor cells outside the vessels. Our results confirm the relevance of mutations in B-cell receptor/nuclear factor-κB signaling and immune escape pathways in IVLBCL and identify novel driver alterations. The similar mutational profile in tumors with extravascular dissemination suggests that these cases may also be considered in the spectrum of IVLBCL.

Molecular Monitoring of Lymphomas

Molecular monitoring of tumor-derived alterations has an established role in the surveillance of leukemias, and emerging nucleic acid sequencing technologies are likely to similarly transform the clinical management of lymphomas. Lymphomas are well suited for molecular surveillance due to relatively high cell-free DNA and circulating tumor DNA concentrations, high somatic mutational burden, and the existence of stereotyped variants enabling focused interrogation of recurrently altered regions. Here, we review the clinical scenarios and key technologies applicable for the molecular monitoring of lymphomas, summarizing current evidence in the literature regarding molecular subtyping and classification, evaluation of treatment response, the surveillance of active cellular therapies, and emerging clinical trial strategies.

The International Consensus Classification of Mature Lymphoid Neoplasms: a report from the Clinical Advisory Committee

Since the publication of the Revised European-American Classification of Lymphoid Neoplasms in 1994, subsequent updates of the classification of lymphoid neoplasms have been generated through iterative international efforts to achieve broad consensus among hematopathologists, geneticists, molecular scientists, and clinicians. Significant progress has recently been made in the characterization of malignancies of the immune system, with many new insights provided by genomic studies. They have led to this proposal. We have followed the same process that was successfully used for the third and fourth editions of the World Health Organization Classification of Hematologic Neoplasms. The definition, recommended studies, and criteria for the diagnosis of many entities have been extensively refined. Some categories considered provisional have now been upgraded to definite entities. Terminology for some diseases has been revised to adapt nomenclature to the current knowledge of their biology, but these modifications have been restricted to well-justified situations. Major findings from recent genomic studies have impacted the conceptual framework and diagnostic criteria for many disease entities. These changes will have an impact on optimal clinical management. The conclusions of this work are summarized in this report as the proposed International Consensus Classification of mature lymphoid, histiocytic, and dendritic cell tumors.

Circulating tumor DNA in B-cell lymphoma: technical advances, clinical applications, and perspectives for translational research

Noninvasive disease monitoring and risk stratification by circulating tumor DNA (ctDNA) profiling has become a potential novel strategy for patient management in B-cell lymphoma. Emerging innovative therapeutic options and an unprecedented growth in our understanding of biological and molecular factors underlying lymphoma heterogeneity have fundamentally increased the need for precision-based tools facilitating personalized and accurate disease profiling and quantification. By capturing the entire mutational landscape of tumors, ctDNA assessment has some decisive advantages over conventional tissue biopsies, which usually target only one single tumor site. Due to its non- or minimal-invasive nature, serial and repeated ctDNA profiling provides a real-time picture of the genetic composition and facilitates quantification of tumor burden any time during the course of the disease. In this review, we present a comprehensive overview of technologies used for ctDNA detection and genotyping in B-cell lymphoma, focusing on pre-analytical and technical requirements, the advantages and limitations of various approaches, and highlight recent advances around improving sensitivity and suppressing technical errors. We broadly review potential applications of ctDNA in clinical practice and for translational research by describing how ctDNA might enhance lymphoma subtype classification, treatment response assessment, outcome prediction, and monitoring of measurable residual disease. We finally discuss how ctDNA could be implemented in prospective clinical trials as a novel surrogate endpoint and be utilized as a decision-making tool to guide lymphoma treatment in the future.

Controversies in the Interpretation of Liquid Biopsy Data in Lymphoma

The rapid evolution of genomic technologies over the last years has led to the development of different methods for the detection, measurement and analysis of cell-free DNA fragments (cfDNA) which are shed into the bloodstream by apoptotic cells and circulate at a low concentration in plasma. In cancer patients, the proportion of tumor-derived cfDNA is defined as circulating tumor DNA. This analysis, commonly known as liquid biopsy, allows to access tumor DNA through a simple blood sampling and therefore without the need of an invasive tissue biopsy. For this reason, this tool may have several clinical applications in terms of diagnosis, prognosis, and monitoring of minimal residual disease. However, there are still several critical issues that need to be resolved. In this review, we will discuss some of the controversies around this method and its potential clinical applications.

Case Report: Intravascular Large B-Cell Lymphoma: A Clinicopathologic Study of Four Cases With Review of Additional 331 Cases in the Literature

Intravascular large B-cell lymphoma (IVLBCL) is a rare and highly malignant non-Hodgkin B-cell lymphoma with uncommon clinical presentation and poor prognosis. The diagnostic pitfall of IVLBCL is mainly due to the fact that subtle histological changes could be easily overlooked, in addition to its rare occurrence, non-specific and variable clinical presentations, and the absence of significant mass lesions. The purpose of this study is to further explore the clinicopathologic and molecular features of IVLBCL to ensure an accurate diagnosis of this entity. Here, we retrospectively present the data of the four new cases and the literature cases. The age ranged from 23 to 92, with a medium age of 67 and a male-to-female ratio of 1:1. The clinical manifestations are extremely variable, including fever, night sweats, weight loss, anemia, thrombocytopenia, unexplained hypoxemia, impaired consciousness, and skin lesions, as well as the extremely low levels of serum albumin, high levels of serum lactate dehydrogenase (LDH), soluble interleukin-2 receptor (sIL2R), and ferritin. Morphologically, 99.9% of cases showed a selective growth pattern with large, atypical lymphocytes within the lumen of small blood vessels. In addition, vast majority of cases were positive for CD20, CD79a, PAX5, MUM1, and BCL6, and a subset of cases expressed BCL2 and CD5, whereas CD3 and CD10 were typically negative. Ki-67 proliferative index ranged from 20% to 100%. To sum up, we have conducted comprehensive case reports, to the best of our knowledge, this is the largest reported cohort of IVLBCL cases. Comprehensive assessments and more IVLBCL cases are required for early diagnosis and prompt treatment.

Intravascular Large B-Cell Lymphoma: A Review with a Focus on the Prognostic Value of Skin Involvement

Intravascular large B-cell lymphoma (IVLBCL) is an aggressive Non-Hodgkin lymphoma (NHL) characterised by the presence of neoplastic lymphoid cells within small- and medium-sized blood vessels. According to the clinical presentation, the current WHO classification distinguishes the 'classic' (formerly 'Western') from a hemophagocytic syndrome-associated (formerly 'Asian') variant. A third 'cutaneous' variant has been proposed, characterised by a good prognosis and unique clinical features. While laboratory findings can hint at diagnosis, symptoms are rather nonspecific, and deep skin biopsy supported by further measures such as bone marrow aspiration and positron emission tomography-computed tomography scanning is needed to make a definite diagnosis. Treatment is comprised of anthracycline-based chemotherapy supplemented with rituximab and central nervous system prophylaxis. While there are various prognostic models for NHL, only one is specific to IVLBCL, which does not sufficiently represent some patient groups, especially regarding the lack of differentiation within the patient collective with skin involvement. This underlines the necessity for the establishment of further prognostic models in particular for IVLBCL patients with cutaneous manifestations.

Circulating Tumor DNA in Lymphoma: Principles and Future Directions

Lymphomas are heterogeneous tumors with striking genetic diversity and variable outcomes even within pathologic diagnoses. Treatment response assessment relies on radiologic and nuclear scans, which cannot detect disease at the molecular level. Molecular tumor analyses require invasive tissue biopsies that cannot accurately capture spatial tumor heterogeneity within each patient. Circulating tumor DNA (ctDNA) is a minimally invasive and highly versatile biomarker that overcomes fundamental limitations of imaging scans and tissue biopsies and may aid clinical decision-making in lymphoma. In this review, we highlight the key established principles regarding ctDNA in lymphoma and emphasize the important research questions and future directions. SIGNIFICANCE: ctDNA is an emerging biomarker for lymphomas that noninvasively provides genotypic information and can measure the effectiveness of treatment by detecting the presence of minimal residual disease. Key principles have emerged related to ctDNA for lymphoma, but further studies are needed to standardize its use and establish clinical utility.

Effect of ibrutinib with R-CHOP chemotherapy in genetic subtypes of DLBCL

In diffuse large B cell lymphoma (DLBCL), tumors belonging to the ABC but not GCB gene expression subgroup rely upon chronic active B cell receptor signaling for viability, a dependency that is targetable by ibrutinib. A phase III trial ("Phoenix;" ClinicalTrials.gov: NCT01855750) showed a survival benefit of ibrutinib addition to R-CHOP chemotherapy in younger patients with non-GCB DLBCL, but the molecular basis for this benefit was unclear. Analysis of biopsies from Phoenix trial patients revealed three previously characterized genetic subtypes of DLBCL: MCD, BN2, and N1. The 3-year event-free survival of younger patients (age ≤60 years) treated with ibrutinib plus R-CHOP was 100% in the MCD and N1 subtypes while the survival of patients with these subtypes treated with R-CHOP alone was significantly inferior (42.9% and 50%, respectively). This work provides a mechanistic understanding of the benefit of ibrutinib addition to chemotherapy, supporting its use in younger patients with non-GCB DLBCL.

Frequent genetic alterations in immune checkpoint-related genes in intravascular large B-cell lymphoma

Intravascular large B-cell lymphoma (IVLBCL) is a unique type of extranodal lymphoma characterized by selective growth of tumor cells in small vessels without lymphadenopathy. Greater understanding of the molecular pathogenesis of IVLBCL is hampered by the paucity of lymphoma cells in biopsy specimens, creating a limitation in obtaining sufficient tumor materials. To uncover the genetic landscape of IVLBCL, we performed whole-exome sequencing (WES) of 21 patients with IVLBCL using plasma-derived cell-free DNA (cfDNA) (n = 18), patient-derived xenograft tumors (n = 4), and tumor DNA from bone marrow (BM) mononuclear cells (n = 2). The concentration of cfDNA in IVLBCL was significantly higher than that in diffuse large B-cell lymphoma (DLBCL) (P < .0001) and healthy donors (P = .0053), allowing us to perform WES; most mutations detected in BM tumor DNA were successfully captured in cfDNA and xenograft. IVLBCL showed a high frequency of genetic lesions characteristic of activated B-cell-type DLBCL, with the former showing conspicuously higher frequencies (compared with nodal DLBCL) of mutations in MYD88 (57%), CD79B (67%), SETD1B (57%), and HLA-B (57%). We also found that 8 IVLBCL (38%) harbored rearrangements of programmed cell death 1 ligand 1 and 2 (PD-L1/PD-L2) involving the 3' untranslated region; such rearrangements are implicated in immune evasion via PD-L1/PD-L2 overexpression. Our data demonstrate the utility of cfDNA and imply important roles for immune evasion in IVLBCL pathogenesis and PD-1/PD-L1/PD-L2 blockade in therapeutics for IVLBCL.

Liquid biopsy in lymphoma: Is it primed for clinical translation?

The simultaneous growth in our understanding of lymphoma biology and the burgeoning therapeutic options has come with a renewed drive for precision-based approaches and how best to incorporate them into contemporary and future patient care. In the hunt for accurate and sensitive biomarkers, liquid biopsies, particularly circulating tumour DNA, have come to the forefront as a promising tool in multiple cancer types including lymphomas, with considerable implications for clinical practice. Liquid biopsy analyses could supplement existing tissue biopsies with distinct advantages including the minimally invasive nature and the ease with which it can be repeated during a patient's clinical journey. Circulating tumour DNA (ctDNA) analyses has been and continues to be evaluated across lymphoma subtypes with potential applications as a diagnostic, disease monitoring and treatment selection tool. To make the leap into the clinic, these assays must demonstrate accuracy, reliability and a quick turnaround to be employed in the real-time clinical management of lymphoma patients. Here, we review the available ctDNA assays and discuss key practical and technical issues around improving sensitivity. We then focus on their potential roles in several lymphoma subtypes exemplified by recent studies and provide a glimpse of different features that can be analysed beyond ctDNA.

Current progress and future perspectives of research on intravascular large B-cell lymphoma

Intravascular large B‐cell lymphoma is a rare disease of the large B cells characterized by selective growth in the lumina of small vessels in systemic organs. Since first reported in 1959, the difficulty of obtaining sufficient tumor cells from biopsy specimens has hampered the elucidation of its underlying biology. Recent progress using xenograft models and plasma cell‐free DNA has uncovered genetic features that are similar to those of activated B‐cell type diffuse large B‐cell lymphoma, including MYD88 and CD79B mutations and frequent alterations in immune check point‐related genes such as PD‐L1 and PD‐L2. Given the improvement in clinical outcomes and a higher risk of secondary central nervous system (CNS) involvement in the rituximab era, a phase 2 trial of R‐CHOP combined with high‐dose methotrexate and intrathecal chemotherapy as a CNS‐oriented therapy has been conducted. This trial, the PRIMEUR‐IVL study, has displayed good progression‐free survival and a low cumulative incidence of secondary CNS involvement. Long‐term follow‐up within this trial is still ongoing. Further understanding of the pathophysiology of the disease and improvements in clinical outcomes are still needed.

Cell-Free Total Nucleic Acid-Based Genotyping of Aggressive Lymphoma: Comprehensive Analysis of Gene Fusions and Nucleotide Variants by Next-Generation Sequencing

Simple Summary

This study aimed to simultaneously demonstrate pathogenic chromosomal translocations and point mutations from both tissue biopsy and peripheral blood (PB) liquid biopsy (LB) samples of aggressive lymphoma patients. Matched samples were analyzed by next-generation sequencing for the same 125 genes. Eight different gene fusions, including the classical BCL2, BCL6, and MYC genes were detected in the corresponding samples with generally good agreement. Besides, mutations of 29 commonly affected genes, such as BCL2, MYD88, NOTCH2, EZH2, and CD79B could be identified in the matched samples at a rate of 16/24 (66.7%). Our prospective study demonstrates a non-invasive approach to identify frequent gene fusions and variants in aggressive lymphomas. In conclusion, PB LB sampling substantially supports the oncogenetic diagnostics of lymphomas, especially at anatomically critical sites (such as the central nervous system).

Abstract

Chromosomal translocations and pathogenic nucleotide variants both gained special clinical importance in lymphoma diagnostics. Non-invasive genotyping from peripheral blood (PB) circulating free nucleic acid has been effectively used to demonstrate cancer-related nucleotide variants, while gene fusions were not covered in the past. Our prospective study aimed to isolate and quantify PB cell-free total nucleic acid (cfTNA) from patients diagnosed with aggressive lymphoma and to compare with tumor-derived RNA (tdRNA) from the tissue sample of the same patients for both gene fusion and nucleotide variant testing. Matched samples from 24 patients were analyzed by next-generation sequencing following anchored multiplexed polymerase chain reaction (AMP) for 125 gene regions. Eight different gene fusions, including the classical BCL2, BCL6, and MYC genes, were detected in the corresponding tissue biopsy and cfTNA specimens with generally good agreement. Synchronous BCL2 and MYC translocations in double-hit high-grade B-cell lymphomas were obvious from cfTNA. Besides, mutations of 29 commonly affected genes, such as BCL2, MYD88, NOTCH2, EZH2, and CD79B, could be identified in matched cfTNA, and previously described pathogenic variants were detected in 16/24 cases (66.7%). In 3/24 cases (12.5%), only the PB sample was informative. Our prospective study demonstrates a non-invasive approach to identify frequent gene fusions and variants in aggressive lymphomas. cfTNA was found to be a high-value representative reflecting the complexity of the lymphoma aberration landscape.

Stance of MRD in Non-Hodgkin's Lymphoma and its upsurge in the novel era of cell-free DNA

Cancer genomics has evolved over the years from understanding the pathogenesis of cancer to screening the future possibilities of cancer occurrence. Understanding the genetic profile of tumors holds a prognostic as well as a predictive value in this era of therapeutic surveillance, molecular remission, and precision medicine. Identifying molecular markers in tumors is the current standard of approach, and requires an efficient combination of an accessible sample type and a profoundly sensitive technique. Liquid biopsy or cell-free DNA has evolved as a novel sample type with promising results in recent years. Although cell-free DNA has significant role in various cancer types, this review focuses on its application in Non-Hodgkin's Lymphoma. Beginning with the current concept and clinical relevance of minimal residual disease in Non-Hodgkin's lymphoma, we discuss the literature on circulating DNA and its evolving application in the realm of cutting-edge technology.

Circulating tumour DNA in B-cell lymphomas: current state and future prospects

Circulating tumour DNA (ctDNA) is a highly versatile analyte and an emerging biomarker for detection of tumour-specific sequences in lymphoid malignancies. Since ctDNA is derived from tumour cells throughout the body, it overcomes fundamental limitations of tissue biopsies by capturing the complete molecular profile of tumours, including those from inaccessible anatomic locations. Assays for ctDNA are minimally invasive and serial sampling monitors the effectiveness of therapy and identifies minimal residual disease below the detection limit of standard imaging scans. Dynamic changes in ctDNA levels measure real-time tumour kinetics, and early reductions in ctDNA during treatment correlate with clinical outcomes in multiple B-cell lymphomas. After therapy, ctDNA can effectively discriminate between patients who achieved a complete molecular remission from those with residual treatment-resistant disease. Serial monitoring of ctDNA after therapy can detect early molecular relapse and identify drug-resistant clones that harbour targetable mutations. In order for ctDNA to reach its full potential, the standardization and harmonization of the optimal pre-analytical and analytical techniques for B-cell lymphomas is a critically necessary requirement. Prospective validation of ctDNA within clinical studies is also required to determine its clinical utility as an adjunctive decision-making tool.

The future of cell-free DNA testing to guide therapeutic decisions in B-cell lymphomas

PURPOSE OF REVIEW

Tissue biopsy is the current gold standard technique for diagnosis and molecular profiling of lymphomas, but it carries several disadvantages in terms of procedural risks (infectious and haemorrhagic complications, anaesthesiologic risks) and analytic aspects (heterogeneity of tumors, low representation of tumor cells in the tissue). Noninvasive genotyping of B-cell lymphomas through circulating tumor DNA (ctDNA) is emerging as a practical tool to monitor the genetics and course of the disease from diagnosis to eventual relapse.This review will explore recent advances in the field of liquid biopsy in lymphomas, highlighting their clinical implications.

RECENT FINDINGS

ctDNA has been recently proposed an alternative source of tumor DNA for genotyping purposes, especially for those samples having low tumor representation or when longitudinal genetic monitoring is limited by the inaccessibility of relapsed tumor tissues. Also, ctDNA has been recently proposed radiation-free tool for the early identification of chemorefractory lymphoma patients.

SUMMARY

The detection of ctDNA circulating in the bloodstream of lymphoma patients can inform about the genetics of the disease at diagnosis identifying druggable alterations, detect the onset of mutation of resistance during treatment, anticipate about relapse earlier than standard methods [e.g. PET associated with computed tomography (PET/CT)] during follow-up.

Plasma circulating tumor DNA assessment reveals KMT2D as a potential poor prognostic factor in extranodal NK/T-cell lymphoma

Background

The early detection of tumors upon initial diagnosis or during routine surveillance is important for improving survival outcomes. Here, we investigated the feasibility and clinical significance of circulating tumor DNA (ctDNA) detection for Extranodal NK/T-cell lymphoma, nasal type (ENTKL).

Methods

The plasma ctDNA assessment was based on blood specimens collected from 65 newly diagnosed patients with ENKTL in the hematology medical center of Xinqiao Hospital. Longitudinal samples collected under chemotherapy were also included. The gene mutation spectrum of ENKTL was analyzed via next generation sequencing.

Results

We found that the most frequently mutated genes were KMT2D (23.1%), APC (12.3%), ATM (10.8%), ASXL3 (9.2%), JAK3 (9.2%), SETD2 (9.2%), TP53 (9.2%) and NOTCH1 (7.7%). The mutation allele frequencies of ATM and JAK3 were significantly correlated with the disease stage, and mutated KMT2D, ASXL3 and JAK3 were positively correlated with the metabolic tumor burden of the patients. Compared with the tumor tissue, ctDNA profiling showed good concordance (93.75%). Serial ctDNA analysis showed that treatment with chemotherapy could decrease the number and mutation allele frequencies of the genes. Compared with PET/CT, ctDNA has more advantages in tracking residual disease in patients. In addition, patients with mutated KMT2D had higher expression compared with those with wild type, and mutated KMT2D predicted poor prognosis.

Conclusion

Our results unveil the mutation spectrum of ENKTL patients' plasma, which can be used to monitor the disease status of the patients exactly, and KMT2D is the most frequently mutated gene with prognosis prediction value. The application of ctDNA sequencing can provide precision treatment strategies for patients.

Trial registration

This study is registered with chictr.org (ChiCTR1800014813, registered 7 February, 2018-Retrospectively registered).

Potential of Circulating Tumor DNA for the Management of Patients With Lymphoma

The characterization of circulating tumor-derived DNA (ctDNA) has recently emerged in the field of oncology as a powerful method to identify tumor-specific genetic aberrations using peripheral blood testing. Several technical precautions are needed at the pre-analytic stage (given the short half-life of free nucleic acids in plasma), and numerous techniques-with different sensitivities-are available to identify these molecular aberrations, ranging from the detection of single point mutations to extended genetic screening panels. Although a "liquid biopsy" cannot be substituted for the pathological examination of tissue specimens for diagnostic purposes, it can sometimes complement pathology results or serve as a proxy approach for particular lymphoma presentations where biopsies are sometimes difficult to perform. Moreover, ctDNA testing can characterize, at diagnosis or during treatment, mutations that may contribute to the choice of an optimal targeted therapy (such as Bruton tyrosine kinase or EZH2 inhibitors) or detect the emergence of resistance to those therapies. High levels of ctDNA before treatment appear to be correlated with advanced disease stages and prognosis in diffuse large B-cell and follicular lymphomas. Real-time follow-up of ctDNA levels during therapy in several lymphoma subtypes (diffuse large B-cell and Hodgkin lymphomas) has been explored: preliminary studies have demonstrated that this monitoring technique can predict clinical outcomes (end of treatment response and risk of progression after treatment completion) and that this approach may complement the information provided by metabolic imaging assessments. Technical standardization and careful prospective evaluation of the role of ctDNA monitoring in clinical studies represent current important challenges to allowing its application in routine practice.

PD-L1 (SP142) expression in neoplastic cells predicts a poor prognosis for patients with intravascular large B-cell lymphoma treated with rituximab-based multi-agent chemotherapy

Background

Intravascular large B‐cell lymphoma (IVLBCL) is a rare form of diffuse large B‐cell lymphoma (DLBCL) arising in extranodal sites. PD‐L1 expression of tumor cells has been reported in IVLBCL cells, but its clinicopathological relevance remains to be elucidated.

Aims

This study was aimed to reveal the characteristics of PD‐L1⁺ IVLBCL.

Methods and results

Neoplastic PD‐L1 expression was examined in 34 cases of IVLBCL and clinicopathological characteristics between patients with PD‐L1⁺ and PD‐L1⁻ IVLBCL were compared. We assessed PD‐L1 expression with SP142 antibody. Twelve (35%) of 34 cases showed positivity for PD‐L1. The PD‐L1⁺ group had significantly lower survival rates compared to the PD‐L1⁻ group. The PD‐L1⁺ IVLBCL group also had a significantly lower age distribution and a lower frequency of patients older than 60 years compared to the PD‐L1⁻ group. Very recently, we speculate that there is possible link between PD‐L1⁺ IVLBCL and PD‐L1⁺ extranodal DLBCL‐NOS (eDLBCL) because features of the two groups showed overlapping. Therefore, we compared the clinicopathological characteristics of the PD‐L1⁺ IVLBCL and PD‐L1⁺ eDLBCL. There were no significant differences in clinicopathological parameters and prognosis.

Conclusion

The worse prognosis of the PD‐L1⁺ group might be caused by immune evasion mechanisms, which are linked to PD‐L1 expression. Therefore, PD‐L1⁺ IVLBCL cases might be regarded as good candidates for targeted immunotherapy. We also highlighted the overlapping features of PD‐L1⁺ IVLBCL and PD‐L1⁺ eDLBCL. This result suggests that they should be regarded as one entity, immune evasion‐related extranodal large B‐cell lymphoma.

Intravascular Large B-cell lymphoma: A case series and review of literatures

Background

Intravascular large B-cell lymphoma (IVLBCL) is a rare subtype of non-Hodgkin lymphoma with uncommon clinical presentations and poor prognosis. The purpose of this study is to report the clinical features and outcome of IVLBCL in a single institution of Taiwan.

Methods

Ten patients with IVLBCL diagnosed from June 2006 to January 2018 were retrospectively reviewed.

Results

The median age was 61 (range 39–88) years. The most common presentation was fever (90%), cytopenia (90%), and confusion (50%). For all patients, the median progression free survival (PFS) and overall survival (OS) were 12.6 (95% confidence interval [CI] 0.0–76.1) and 18.8 (95% CI 0–59.3) months, respectively. Six patients received rituximab combined chemotherapy, and the other one patient was treated with chemotherapy alone. Six of seven (85.7%) patients achieved complete response after chemotherapy. The median PFS and OS for six patients who completed treatment were not reached. Three-year PFS and OS rates were 80% and 75%, respectively.

Conclusion

Our study showed that patients might achieve durable remission after rituximab-based chemotherapy. The outcome of IVLBCL patients may further improve if early diagnosis and prompt treatment were made.

A Probabilistic Classification Tool for Genetic Subtypes of Diffuse Large B Cell Lymphoma with Therapeutic Implications

The development of precision medicine approaches for diffuse large B cell lymphoma (DLBCL) is confounded by its pronounced genetic, phenotypic, and clinical heterogeneity. Recent multiplatform genomic studies revealed the existence of genetic subtypes of DLBCL using clustering methodologies. Here, we describe an algorithm that determines the probability that a patient's lymphoma belongs to one of seven genetic subtypes based on its genetic features. This classification reveals genetic similarities between these DLBCL subtypes and various indolent and extranodal lymphoma types, suggesting a shared pathogenesis. These genetic subtypes also have distinct gene expression profiles, immune microenvironments, and outcomes following immunochemotherapy. Functional analysis of genetic subtype models highlights distinct vulnerabilities to targeted therapy, supporting the use of this classification in precision medicine trials.

The role of cell free DNA and liquid biopsies in haematological conditions

Cell free nucleic acids (CFNAs) are nucleic acids released from cells that circulate within bodily fluids. Recent advances in molecular techniques have led the ability to interrogate CFNAs in a clinically meaningful way, for example the identification and assessment of foetal CFNAs in maternal blood, allowing minimally invasive testing for foetal genetic abnormalities. The majority of CFNAs arise from haemopoietic cells, making it a particularly rich source of genetic information in haematological conditions. Furthermore, the innate genetic heterogeneity of haematological malignancies, as epitomised by multiple myeloma, lend itself well to “liquid biopsies”. This approach promises to provide a more wholistic assessment of whole disease genetics, especially when contrasted against the current gold-standard of single site tissue biopsies. This review briefly summarises the definitions and physiology of CFNAs, both cell free DNA (cfDNA) and extracellular RNA (exRNA), before exploring the literature surrounding the current and future roles of cfDNA in the haematological malignancies and patient care.

Rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone combined with high-dose methotrexate plus intrathecal chemotherapy for newly diagnosed intravascular large B-cell lymphoma (PRIMEUR-IVL): a multicentre, single-arm, phase 2 trial

BACKGROUND

Intravascular large B-cell lymphoma (IVLBCL) is a rare disease for which there is no available standard treatment. We aimed to ascertain the safety and activity of R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone) with high-dose methotrexate and intrathecal chemotherapy as CNS-oriented therapy for patients with previously untreated IVLBCL.

METHODS

PRIMEUR-IVL is a multicentre, single-arm, phase 2 trial at 22 hospitals in Japan. Eligible patients had untreated histologically confirmed IVLBCL, were aged 20-79 years, had an Eastern Cooperative Group performance status of 0-3, and had no apparent CNS involvement at diagnosis. Patients received three cycles of R-CHOP (rituximab 375 mg/m² intravenously on day 1 [except cycle one, which was on day 8]; cyclophosphamide 750 mg/m², doxorubicin 50 mg/m², and vincristine 1·4 mg/m² [maximum 2·0 mg] intravenously on day 1 of cycle one and day 2 of cycles two and three; and prednisolone 100 mg/day orally on days 1-5 of cycle one and days 2-6 of cycles two and three) followed by two cycles of rituximab with high-dose methotrexate (3·5 g/m² intravenously on day 2 of cycles four and five) every 2 weeks and three additional cycles of R-CHOP. Intrathecal chemotherapy (methotrexate 15 mg, cytarabine 40 mg, and prednisolone 10 mg) was administered four times during the R-CHOP phase. The primary endpoint was 2-year progression-free survival. Efficacy analyses were done in all enrolled patients; safety analyses were done in all enrolled and treated patients. The trial is registered in the UMIN Clinical Trials Registry (UMIN000005707) and the Japan Registry of Clinical Trials (jRCTs041180165); the trial is ongoing for long-term follow-up.

FINDINGS

Between June 16, 2011, and July 21, 2016, 38 patients were enrolled, of whom 37 were eligible; one patient was excluded because of a history of testicular lymphoma. Median follow-up was 3·9 years (IQR 2·5-5·5). 2-year progression-free survival was 76% (95% CI 58-87). The most frequent adverse events of grade 3-4 were neutropenia and leucocytopenia, which were reported in all 38 (100%) patients. Serious adverse events were hypokalaemia, febrile neutropenia with hypotension, hypertension, and intracerebral haemorrhage (reported in one [3%] patient each). No treatment-related deaths occurred during protocol treatment.

INTERPRETATION

R-CHOP combined with rituximab and high-dose methotrexate plus intrathecal chemotherapy is a safe and active treatment for patients with IVLBCL without apparent CNS involvement at diagnosis, and this regimen warrants future investigation.

FUNDING

The Japan Agency for Medical Research and Development, the Center for Supporting Hematology-Oncology Trials, and the National Cancer Center.

A Western Case of Intravascular Large B-Cell Lymphoma as Unusual Cause of Persistent Fever

Fever of unknown origin (FUO) is a common and challenging clinical condition that can be referred, among others, to infections, drug's effects, various inflammatory disorders, and cancers. Among the latter, lymphomas can indeed cause fever, which is therefore accounted as a lymphoma-related sign in patients' staging. Intravascular large B-cell lymphoma (IVLBCL) is a very rare tumor, characterized by lymphoma cell accumulation within sinusoids and, despite a very aggressive course, the evidence of this disease is scarce. Two variants are currently recognized, respectively, occurring in either Western (mainly characterized by neurological symptoms and skin involvement) or Eastern countries (with hemophagocytic syndrome, bone marrow, spleen, and liver involvement). We describe an atypical and unprecedented IVLBCL patient, presenting with pronounced features of Eastern cases as well as skin involvement. Due to the scant amount of neoplastic cells, the diagnosis was very challenging, with FUO being the first and for a certain time unique clinical sign. Although lymphoma was suspected, the lack of evidence for neoplastic cells delayed the final diagnosis. Eventually, only autopsy revealed the extensive involvement of different organs and tissues.

Diffuse large B-cell lymphoma variants: an update

Diffuse large B-cell lymphoma (DLBCL) is the most common type of lymphoma, representing approximately one-third of all cases worldwide. In the World Health Organization (WHO) classification of lymphomas, most cases of DLBCL are designated as not otherwise specified (NOS). About 20% of cases, however, are designated as specific variants of DLBCL. These variants, 13 in total, are specified on the basis of distinctive morphological or immunophenotypic findings or distinctive biological or clinical issues associated with their diagnoses. In this review we discuss the following variants: T-cell/histiocyte-rich large B-cell lymphoma; ALK-positive large B-cell lymphoma; plasmablastic lymphoma; intravascular large B-cell lymphoma; large B-cell lymphoma with IRF4 rearrangement; primary mediastinal large B-cell lymphoma; primary cutaneous diffuse large B-cell lymphoma, leg type; primary diffuse large B-cell lymphoma of the central nervous system; diffuse large B-cell lymphoma associated with chronic inflammation; lymphomatoid granulomatosis; primary effusion lymphoma; and HHV8-positive diffuse large B-cell lymphoma, NOS. Two additional variants recognised in the WHO classification, EBV-positive diffuse large B-cell lymphoma and EBV-positive mucocutaneous ulcer are discussed elsewhere in another review within this issue of Pathology. Although not recognised as a specific variant in the current WHO classification, primary testicular diffuse large B-cell lymphoma also has unique biological features and requires some modification of the standard treatment approach for patients with DLBCL. Therefore, we suggest that primary testicular diffuse large B-cell lymphoma also should be recognised as a specific variant of DLBCL in a future version of the WHO classification.

Cell-free DNA and the monitoring of lymphoma treatment

The technique of cell-free DNA (cfDNA) analysis, also called liquid biopsy, has been developed over the past several years to serve as a minimal residual disease tool, as has already been done with reliability and robustness in acute leukemias. This technique has important theoretical advantages, including the simplicity of acquiring blood samples, which can easily be repeated over time, its noninvasive and quantitative nature, which provides results consistent with the results obtained from tumor genomic DNA, and its speed and low cost. cfDNA analysis, as the leading tool to quantify somatic mutations, is a major technological leap in the noninvasive management of lymphomas. This technology may empower monitoring and treatment adjustment in real time and enable the quick detection of refractory lymphomas and resistance to routine therapies. Here, we summarize the results that have established the clinical relevance of cfDNA in diagnostic and prognostic stratification and the monitoring of lymphoma treatments.

Diagnosis of intravascular large B cell lymphoma: novel insights into clinicopathological features from 42 patients at a single institution over 20 years

This study aimed to clarify the comprehensive clinical, laboratory, pathological and imaging features of intravascular large B‐cell lymphoma (IVLBCL) using data on 42 IVLBCL patients diagnosed at our hospital over the past 20 years. The majority of patients were diagnosed via random skin biopsy (29/42, 69·0%) followed by bone marrow biopsy alone (8/42, 19·0%). Characteristic features included persistent fever (41/42, 97·6%), decreased performance status (≥2) (100%), hypoxaemia (32/40, 80·0%), impaired consciousness (19/42, 45·2%), hypoalbuminemia (42/42, 100%) and extreme elevation of lactate dehydrogenase and soluble interleukin 2 receptor levels. Brain magnetic resonance imaging showed abnormal findings in 32/37 patients (86·4%). Hyperintense lesion in the pons was a peculiar finding that was unrelated to the neurological deficits. Positron emission tomography‐computed tomography revealed a high incidence of bone marrow (26/34, 76·5%), spleen (19/34, 55·9%) and adrenal gland (9/34, 26·5%) involvement. Neurolymphomatosis was noted in 6 patients during the course of the disease. About 60% of IVLBCL patients in whom in vivo diagnosis was possible survived more than 5 years with combination chemotherapy. Our observations provide additional insight into the diagnosis of IVLBCL and indicate that early disease recognition via random skin biopsy combined with imaging, enables in vivo diagnosis of the disease and improved survival for many patients.

Timely Diagnosis and Successful Treatment of Intravascular Large B-Cell Lymphoma in an Elderly Patient with Poor Performance Status

BACKGROUND Intravascular large B-cell lymphoma (IVLBCL) is a rare type of extranodal large B-cell lymphoma characterized by involvement of lymphoma cells in the lumina of small blood vessels in various organs. Although many studies have claimed that timely diagnosis and early initiation of chemotherapy are important, the literature on the successful treatment of IVLBCL in elderly patients over the age of 80 years is scarce. CASE REPORT An 82-year-old man presented with abnormal elevation of lactate dehydrogenase at 1605 IU/L and altered mental status, which manifested as forgetfulness, abnormal behavior, and worsening performance status for 2 days. There was no evidence of lymphadenopathy or skin lesions, but a computed tomography scan of the chest showed bilateral diffuse ground-glass opacities. With a primary consideration of IVLBCL, random skin biopsy and transbronchial lung biopsy were performed. Immediately after the pathologic findings on hematoxylin-eosin staining alone revealed abnormal large cells in the small vessels, chemotherapy with cyclophosphamide, doxorubicin, vincristine, and prednisolone (CHOP) at half the usual dose was started; later on, immunostaining revealed CD20 expression in the abnormal lymphoid cells. Immediately after CHOP administration, his mental and physical symptoms rapidly resolved. After 8 cycles of dose-reduced CHOP with rituximab, he remained free from disease progression 2 years after the diagnosis. CONCLUSIONS We presented a case of successful early chemotherapy for IVLBCL in an elderly patient with poor performance status. Early chemotherapy with CHOP, even before obtaining a definitive diagnosis based on immunostaining, may contribute to good outcomes.

Updates on Circulating Tumor DNA Assessment in Lymphoma

PURPOSE OF REVIEW

The use of circulating tumor DNA (ctDNA) for the purposes of diagnosis, prognosis, assessment of treatment response, and monitoring for relapse is a new and developing field in lymphoma. This review aims to summarize many of the most recent advances in ctDNA applications.

RECENT FINDINGS

Recent studies have demonstrated the use of ctDNA assessment across many lymphoma subtypes including diffuse large B-cell lymphoma, follicular lymphoma, Hodgkin lymphoma, and T-cell lymphoma. In addition, many novel applications of ctDNA assessment have been described such as the development of new prognostic models, investigation of clonal evolution and heterogeneity, early assessment of treatment response, and prediction of response to targeted therapy as a form of personalized medicine. The use of ctDNA has been shown to be feasible across many lymphoma subtypes and has shown significant promise for several new applications. Additional studies will be needed to validate these findings prior to routine use in clinical practice.

CD30 expression in a case of intravascular large B-cell lymphoma, cutaneous variant

Intravascular large B-cell lymphoma (IVLBCL) is one of the rarest B-cell non-Hodgkin lymphomas (NHL), with an aggressive clinical behavior and a poor prognosis; in fact, its treatment is still an unmet clinical need, with a 3-year overall survival (OS) rate of 60% to 81%, and a central nervous system relapse rate of 25%. It usually presents as a widespread disease at diagnosis, with multi-organ involvement. Previously considered as a diffuse large B-cell lymphoma variant, it now represents a different extranodal large B-cell lymphoma entity in the last WHO Classification of tumors of hematopoietic and lymphoid tissues. We hereby describe the case of an 84-year-old Italian woman with an IVLBCL, cutaneous variant, who suffered from early relapse after R-COMP chemotherapy regimen, and was therefore treated with a palliative metronomic chemotherapy. Interestingly, neoplastic cells showed CD30 expression at relapse. CD30 positivity has never been reported in this disease so far, and its expression is known to be involved in NF-kB activation. CD30 expression may be further studied as for prognostic and therapeutic significance; in fact, new therapeutic strategies, such as antibody-drug conjugate targeting CD30, are now available.

CD5-Positive Intravascular Large B-Cell Lymphoma in a Patient with Wilson's Disease: Case Report and Review of the Literature

Intravascular large B-cell lymphoma (IVLBCL) is a rare extra-nodal B-cell lymphoma that proliferates within small/intermediate blood vessels and capillaries while sparing large blood vessels and organ parenchyma. Clinical presentation is highly variable and may include B symptoms, neurological deficits, and/or cutaneous findings. The diagnosis of IVLBCL is difficult due to multiorgan involvement and nonspecific symptoms. We describe the case of a 68-year-old male who presented with progressive weakness, confusion, and falls. He had a past medical history of liver cirrhosis secondary to Wilson's disease. Physical exam and laboratory results revealed a lethargic man with jaundice, hepatic encephalopathy, and abnormal liver/kidney function tests. He expired after a short hospital course in the setting of hepatic and renal failure. Postmortem examination revealed large neoplastic lymphoid cells involving multiple organ blood vessels; however skin and neurologic involvement was absent. The neoplastic cells demonstrated B-cells positive for CD5, rendering a diagnosis of IVLBCL. Our case represents the occurrence of IVLBCL with CD5-positivity in a patient with Wilson's disease, diagnosed at autopsy demonstrating the challenging nature of diagnosing IVLBCL.