Guideline for the diagnosis and management of marginal zone lymphomas: a British Society of Haematology guideline

The objective of this guideline is to provide healthcare professionals with clear guidance on the diagnosis and management of patients with marginal zone lymphoma (MZL).

Prognostic factors for relapse and survival among patients with ocular adnexal lymphoma: validation of the eighth edition of the American Joint Committee on Cancer (AJCC) TNM classification.

BACKGROUND/AIMS: To validate the prognostic performance of the American Joint Committee on Cancer (AJCC) eighth edition classification for ocular adnexal lymphoma (OAL). METHODS: We performed a retrospective review of 140 consecutive patients treated for primary OAL between March 2010 and September 2017. Associations between T/N/M categories at presentation and disease-related outcomes, including relapse, progression-free survival (PFS) and overall survival (OS) were evaluated. RESULTS: Seventy-nine women and 61 men (median age, 52 (range 20-84) years; median follow-up, 57 (range 7-131) months) were included. Histological subtypes included mucosa-associated lymphoid tissue lymphoma (92.1%, n=129), diffuse large B-cell lymphoma (5.0%, n=7), follicular lymphoma (1.4%, n=2) and mantle cell lymphoma (1.4%, n=2). Patients with ≥T2 disease had significantly higher risks of overall relapse (unadjusted HR)=4.32, p=0.016), decreased PFS (uHR=5.19, p=0.004) and decreased OS (uHR=9.21, p=0.047). Patients with ≥N1 disease had significantly higher risks of overall relapse (uHR=9.17, p<0.001) and decreased PFS (uHR=9.24, p<0.001). M1 disease was significantly associated with higher risks of overall relapse (uHR=3.62, p=0.036), decreased PFS (uHR=5.13, p=0.001) and decreased OS (uHR=9.24, p=0.013). On considering TNM categories as continuous data, the uHRs for per level increase in T, N and M categories were 1.77, 1.83 and 2.30 for overall relapse and 1.72, 1.87 and 2.78 for decreased PFS, respectively (p<0.05 for each comparison). CONCLUSION: The T, N and M categories of the AJCC eighth edition classification have prognostic value for relapse and survival among patients with primary OAL. Particularly, nodal/metastatic involvement at presentation indicated less favourable outcome.

Actualités dans les lymphomes à petites cellules non folliculaires.

Non-follicular small cell lymphomas include several entities whose clinical and pathological descriptions have been refined in the last 20 years. MALT lymphoma, developed at the expense of lymphoid tissue associated with the mucosa, is usually localized to a given organ, but can also disseminate. Some patients with MALT lymphoma can be treated by eradicating the associated infectious agent, whereas local treatment should be preferred for other cases ; disseminated forms and relapsed patients are eligible for anti-CD20 antibodies associated with cytotoxic agents. Patients with mantle cell lymphoma have benefited from many advances, including the use of cytarabine and bendamustine, anti-CD20 antibodies, intensive treatments (autograft) and recently targeted therapy (ibrutinib, inhibitor or the Bruton tyrosine kinase). Patients with splenic nodal marginal zone lymphomas should be evaluated for different options, of which immunochemotherapy remains important. For all these entities, the implementation of treatments may be delayed by several years for certain groups of patients. Although considered as incurable, the prognosis of these pathologies has improved significantly and the majority of patients will be able to live for many years with often treatment-free intervals.

IRTA1 and MNDA Expression in Marginal Zone Lymphoma: Utility in Differential Diagnosis and Implications for Classification.

Objectives: To evaluate the clinical utility of immune receptor translocation-associated protein 1 (IRTA1) and myeloid nuclear differentiation antigen (MNDA) expression in the diagnosis and classification of marginal zone lymphomas (MZLs). Methods: IRTA1 was examined using a novel RNA in situ hybridization assay and MNDA expression determined by immunohistochemistry in 127 small B-cell neoplasms, including 80 cases of MZL. Results: IRTA1 expression was detected in 31 (42%) of 74 MZLs vs one (2%) of 43 other small B-cell neoplasms (P < .001). MNDA staining was positive in 51 (64%) of 79 MZLs vs 21 (45%) of 46 non-MZLs (P = .06). MNDA expression was particularly uncommon in follicular lymphoma (3/14, 21%; P = .003 vs MZL). There was no association between MNDA and IRTA1 expression and the presence of monocytoid cytology. IRTA1 expression was less frequent in cases with a diffuse growth pattern. Conclusions: IRTA1 and MNDA are useful markers in the differential diagnosis of MZLs.

Cutaneous B-cell lymphomas: 2019 update on diagnosis, risk stratification, and management.

DISEASE OVERVIEW: Approximately one-fourth of cutaneous lymphomas are B-cell derived and are generally classified into three distinct subgroups: primary cutaneous follicle center lymphoma (PCFCL), primary cutaneous marginal zone lymphoma (PCMZL), and primary cutaneous diffuse large B-cell lymphoma, leg type (PCDLBCL, LT). DIAGNOSIS: Diagnosis and disease classification are based on histologic review and immunohistochemical staining of an appropriate skin biopsy. Pathologic review and an appropriate staging evaluation are necessary to distinguish primary cutaneous B-cell lymphomas from systemic B-cell lymphomas with secondary skin involvement. RISK STRATIFICATION: Disease histology remains the most important prognostic determinant. Both PCFCL and PCMZL are indolent lymphomas that infrequently disseminate to extracutaneous sites and are associated with 5-year survival rates that exceed 95%. In contrast, PCDLBCL, LT is an aggressive lymphoma with an inferior prognosis. RISK-ADAPTED THERAPY: PCFCL and PCMZL patients with solitary or relatively few skin lesions may be affectively managed with local radiation therapy. While single-agent rituximab may be employed for patients with more widespread skin involvement, multiagent chemotherapy is rarely appropriate. In contrast, management of patients with PCDLBCL, LT is comparable to the management of patients with systemic DLBCL.

Reexamining post-transplant lymphoproliferative disorders: Newly recognized and enigmatic types.

Post-transplant lymphoproliferative disorders (PTLD) are a known risk for both solid organ transplant and stem cell transplant recipients. Overall transplant recipients have a six fold increase in risk for developing any kind of non-Hodgkin lymphoma and PTLDs occur in up to 10% of SOT recipients. Several new entities have been accepted or renamed in the 2018 update of the WHO classification of tumors of hematopoietic and lymphoid neoplasms, including florid follicular hyperplasia and extranodal marginal zone lymphomas of mucosa-associated lymphoid tissue (MALT-lymphoma) (excluding common locations such as stomach and salivary gland). Other more rare types of PTLD have been reclassified including EBV-positive mucocutaneous ulcer, which is now a recognized diagnosis in its own right and should not be considered polymorphous PTLD. In this paper newly recognized PTLD entities and more unusual PTLDs will be examined.

Distribution of lymphoid neoplasms in Northwest China: Analysis of 3244 cases according to WHO classification in a single institution.

To explore the distribution of lymphoid neoplasms in Northwest China, the clinical and pathological data of lymphoma patients from 2006 to 2014 were analyzed according to the WHO classification in Xijing Hospital. Of the 3244 cases, mature B-cell neoplasms occupied 60.7%, while mature T/NK-cell neoplasms and Hodgkin's lymphomas (HL) occupied 26.2% and 8.1%, respectively. The most common subtype of lymphoma was diffuse large B-cell lymphoma (35.0%), followed by extranodal NK/T-cell lymphoma, nasal type (ENKTCL) (12.9%) and marginal zone B-cell lymphoma (7.8%). Mixed cellularity (34.0%) was the most common subtype of HL. The especially high proportion of ENKTCL was the most outstanding feature of our study in comparison to previous reports. The mean age of all lymphoid neoplasms cases was 51years and most subtypes showed male predominance, with an average male-female ratio of 1.6. Extranodal lymphomas took up about 60% of all cases and gastrointestinal tract was the most frequently involved site. In conclusion, the distribution of lymphoid neoplasms of Northwest China showed some features similar to previous reports of China and other countries, but some subtypes presented distinct features.

Marginal Zone Lymphoma: Clinicopathologic Variations and Approaches to Therapy.

PURPOSE OF REVIEW: The purpose of the study is to summarize the current conundrums in the management of marginal zone lymphomas (MZL). RECENT FINDINGS: In 2017, the US Food and Drug Administration (FDA) approved ibrutinib, a first in class Bruton Tyrosine Kinase inhibitor, for the treatment of relapsed/refractory MZL based on pivotal open-label phase II trial demonstrating an overall response rates of 48%. Clinical trials design utilizing chemotherapy-free regimens for relapsed/refractory disease are gaining popularity. Recent studies have identified multiple genetic biomarkers that helped characterize and prognosticate different subtypes of MZL. MZLs are heterogeneous, mostly indolent, malignancies derived from B lymphocytes. Three disease subtypes are recognized, extranodal, nodal, and splenic. The disease characteristics, clinical picture, and treatment algorithms vary considerably based on subtype and site of involvement. Recent discoveries have enhanced our knowledge of the pathogenesis of MZLs leading to development of more accurate prognostic models as well as novel targeted systemic therapies.

Pathology of nodal marginal zone lymphomas.

Nodal marginal zone B cell lymphomas (NMZLs) are a rare group of lymphoid disorders part of the spectrum of marginal zone B-cell lymphomas, which encompass splenic marginal one B-cell lymphoma (SMZL) and extra nodal marginal zone of B-cell lymphoma (EMZL), often of MALT-type. Two clinicopathological forms of NMZL are recognized: adult-type and pediatric-type, respectively. NMZLs show overlapping features with other types of MZ, but distinctive features as well. In this review, we will focus on the salient distinguishing features of NMZL mostly under morphological/immunophenotypical/molecular perspectives in views of the recent acquisitions and forthcoming updated 2016 WHO classification of lymphoid malignancies.

[Mediastinal lymphomas]. / Lymphome des Mediastinums.

Lymphomas infiltrating the mediastinum are a challenge for the treating physician as well as for the pathological diagnostics. The clinical scenario is often an emergency situation, while the pathologist is usually confronted only with small biopsy samples. Classical Hodgkin's lymphoma is by far the most frequently occurring lymphoma in the mediastinum and predominantly the nodular sclerosis subtype. In small and very sclerotic specimens it can be difficult to morphologically detect Hodgkin and Reed-Sternberg cells and to identify the characteristic phenotype by immunohistochemistry. Primary mediastinal large B­cell lymphomas should be distinguished from classical Hodgkin's lymphomas as the treatment is different. This is characterized by the detection of sheets of blast cells, which immunohistochemically show a strong B­cell phenotype (positivity for CD20 and CD79a), while CD30 can also often be expressed. The intimate biological relationship between classical Hodgkin's lymphomas and mediastinal large B­cell lymphomas is illustrated by the existence of B­cell lymphomas with intermediate features (so-called mediastinal grey zone lymphomas). It is important to recognize and diagnose these lymphomas as they are associated with a slightly inferior prognosis. Extranodal thymic marginal zone lymphomas of the mucosa-associated lymphoid tissue (MALT) type are a rare form of lymphoma encountered in the mediastinum, which can be associated with autoimmune diseases. T­lymphoblastic lymphomas and leukemia, which occur predominantly in children and young adults, represent a rapidly growing precursor cell neoplasia and must be distinguished from thymomas in the differential diagnostics as well as from normal and hyperplastic thymus glands.

Diagnosis and Management of Cutaneous B-cell Lymphoma.

The diagnosis of primary cutaneous B-cell lymphoma (CBCL) requires that the search for a more widespread lymphoma has been negative. The clinical presentation, outlook, and treatment options of the common types of CBCLs, with emphasis on differences or similarities to their nodal counterparts, are discussed. Treatment may range from observation to topical therapies to systemic therapies, depending on the histology, degree and area of skin involvement, patient performance, and comorbidities. Rare lymphomas, such as intravascular large B-cell lymphoma and Epstein-Barr virus-positive cutaneous lymphoproliferations that are associated with immunodeficiency, are also briefly described.

Clinicopathological analysis of small-sized anterior mediastinal tumors.

PURPOSE: The purpose of this study was to determine the clinicopathological findings and prognosis of small-sized anterior mediastinal tumors (SSAMTs). METHODS: A retrospective study was conducted on 43 patients who underwent surgery between January 1989 and December 2011 for SSAMTs. RESULTS: From the preoperative radiological findings, the tumors were classified into solid (n = 28) and cystic lesions (n = 15). The pathological diagnoses of the solid lesions included thymoma (n = 24), thymic carcinoma (n = 1), mucosa-associated lymphoid tissue lymphoma (n = 1), teratoma (n = 1) and neurofibroma (n = 1), and those of the cystic lesions included thymic cysts (n = 8), thymoma (n = 3), bronchogenic cysts (n = 2), teratoma, (n = 1) and a pericardial cyst (n = 1). The 27 thymomas were composed of stages I (n = 22), II (n = 3), III (n = 1) and IVb (n = 1). The overall survival in the 43 patients was 97.1 % at 5 years. In the 28 patients with solid lesions, the overall survival was 95.8 % at 5 years. All patients with cystic lesions were still alive at the last follow-up. CONCLUSION: Cystic lesions of SSAMTs were benign lesions or stage I thymoma, and most of the solid lesions of SSAMTs were stage I or II thymomas. SSAMTs are good candidates for video-assisted thoracic surgery procedures, as conversion to sternotomy can be selected based on the intraoperative findings of pericardial invasion and a rapid pathological diagnosis of thymic carcinoma.

Clonal B-cell lymphocytosis exhibiting immunophenotypic features consistent with a marginal-zone origin: is this a distinct entity?

The biological and clinical significance of a clonal B-cell lymphocytosis with an immunophenotype consistent with marginal-zone origin (CBL-MZ) is poorly understood. We retrospectively evaluated 102 such cases with no clinical evidence to suggest a concurrent MZ lymphoma. Immunophenotyping revealed a clonal B-cell population with Matutes score ≤2 in all cases; 19/102 were weakly CD5 positive and all 35 cases tested expressed CD49d. Bone marrow biopsy exhibited mostly mixed patterns of small B-lymphocytic infiltration. A total of 48/66 (72.7%) cases had an abnormal karyotype. Immunogenetics revealed overusage of the IGHV4-34 gene and somatic hypermutation in 71/79 (89.8%) IGHV-IGHD-IGHJ gene rearrangements. With a median follow-up of 5 years, 85 cases remain stable (group A), whereas 17 cases (group B) progressed, of whom 15 developed splenomegaly. The clonal B-cell count, degree of marrow infiltration, immunophenotypic, or immunogenetic findings at diagnosis did not distinguish between the 2 groups. However, deletions of chromosome 7q were confined to group A and complex karyotypes were more frequent in group B. Although CBL-MZ may antedate SMZL/SLLU, most cases remain stable over time. These cases, not readily classifiable within the World Heath Organization classification, raise the possibility that CBL-MZ should be considered as a new provisional entity within the spectrum of clonal MZ disorders.

Is bone marrow biopsy always indicated in patients with primary cutaneous marginal zone B-cell lymphoma?

Bone marrow involvement at the time of diagnosis is uncommon in patients with primary cutaneous marginal zone B-cell lymphoma (PCMZL). Moreover, in these patients such involvement is rarely found in isolation on diagnosis. Typically the few patients with PCMZL who have early bone marrow involvement also present secondary nodal or visceral involvement, which is detected by other staging studies (usually computed tomography). In recent years, this has given rise to some debate about whether a bone marrow biopsy should be routinely performed in patients diagnosed with PCMZL in view of the good prognosis and low incidence of bone marrow infiltration and/or extracutaneous involvement in this type of lymphoma.

Primary cutaneous B-cell lymphomas: part I. Clinical features, diagnosis, and classification.

Primary cutaneous B-cell lymphomas (PCBCLs) are defined as lymphomas with a B-cell phenotype that present in the skin without evidence of systemic or extracutaneous disease at initial presentation, after adequate staging. In non-Hodgkin lymphomas, the skin is the second most common site of extranodal involvement after the gastrointestinal tract. PCBCLs are histologically very similar to their nodal counterparts, and these histologic similarities can lead to confusion about both therapy and prognosis. This article will summarize the clinical, pathologic, and diagnostic features of the 3 main types of PCBCL: primary cutaneous follicle center lymphoma, primary cutaneous marginal zone lymphoma, and primary cutaneous diffuse large B-cell lymphoma, leg-type, and the appropriate evaluation and staging procedures for each of these entities.

Current concepts on cutaneous MALT lymphomas.

Concepts on cutaneous mucosa-associated lymphoid tissue lymphomas have been one of the most evolving areas of interest in dermatopathology in the past few decades. Researchers not only have modified the classification of such entities from the old concept of immunocytoma but have also developed a better understanding about how such lymphomas evolve from a chronic stimulating environment and about their associated genetic alterations. Because the latest advances point to the existence of several types of cutaneous mucosa-associated lymphoid tissue lymphomas, we believe that clarity about the concepts on marginal-zone cells can only contribute to the understanding of this fascinating type of lymphoma.

IGHV gene features and MYD88 L265P mutation separate the three marginal zone lymphoma entities and Waldenström macroglobulinemia/lymphoplasmacytic lymphomas.

To clarify the relationships between marginal zone lymphomas (MZLs) and Waldenström macroglobulinemia/lymphoplasmacytic lymphomas (WM/LPLs), immunoglobulin heavy chain variable gene (IGHV) features were analyzed and the occurrence of MYD88 L265P mutations was identified in a series of 123 patients: 53 MZLs from the spleen (SMZLs), 11 from lymph nodes (NMZLs), 28 mucosa-associated lymphatic tissue (MALT) lymphomas and 31 WM/LPLs. SMZLs were characterized by overrepresentation of IGHV1-2 gene rearrangements with a canonical motif, without selection pressure and with long CDR3 segments. NMZLs had increased frequencies of IGHV3 genes. The IGHV gene was unmutated in most cases, often with long CDR3 segments. MALT lymphomas were usually associated with a mutated IGHV gene, but with the absence of selection pressure. WM/LPLs were associated with an IGHV3-23 overrepresentation and high IGHV mutation rate, with features of selection pressure and short CDR3 segments. MYD88 L265P mutations were almost restricted exclusively to WM/LPL patients. Taken all diagnoses together, all patients with MYD88 L265P mutations had an immunoglobulin M peak and almost all patients except one had bone marrow infiltration. These results demonstrate that the history of antigen exposure of the four entities studied was different and MYD88 L265P was specifically associated with WM/LPLs. WM/LPL may thus be functionally associated with constitutive nuclear factor-κB activation.