Utility of leukocyte-associated immunoglobulin-like receptor-1 (CD305) in flow cytometric detection of minimal bone marrow involvement by B-cell non-Hodgkin lymphoma

Multicolor flow cytometry (MFC) is crucial in detecting occult or minimal bone marrow (BM) involvement by non-Hodgkin lymphomas (NHL), which may not be detected using trephine biopsy or imaging studies. Detection of low-level BM involvement can be challenging without definite immunophenotypic aberrancies. We studied the utility of CD305 in MFC detection of minimal BM involvement by B-NHL, especially in the absence of aberrancies by commonly used markers. The study included 1084 consecutive BM samples submitted for the staging of B-NHLs (excluding CLL) over two years. Samples were studied for morphological, immunophenotypic, and histopathological assessment. MFC studies were performed using 10-13 color MFC, including CD305-antibody (clone, DX26). Minimal BM involvement was defined with a cutoff of ≤10% lymphoma cells in viable cells on MFC assessment. Of 1084, 148 samples revealed overt morphological involvement by B-NHL and were excluded from analysis. BM samples of 172/936 patients were morphologically negative but revealed involvement using MFC independently. Corresponding trephine biopsy involvement was detected in only 79/172 (45.9%) patients. On MFC, 23/172 samples showed BM involvement with >10% lymphoma cells, and 149/172 (86.6%) samples revealed minimal involvement. In 54/149 (36.24%) samples, lymphoma cells were detected only with aberrant loss of CD305 expression. In 78 of the remaining 95 samples (82.1%), it provided an immunophenotypic aberrancy addition to other markers and supported the results. CD305 is a highly useful marker in the flow cytometric assessment of minimal BM involvement by B-NHL. MFC is a superior modality to trephine biopsy in detecting low-level BM involvement.

Splenic marginal zone lymphoma with monoclonal IgG: A case report

RATIONALE

Splenic marginal zone lymphoma (SMZL), an indolent small B-cell lymphoma, is uncommon, and part of the patients exist plasmocytic differentiation and secrete monoclonal paraproteins including IgM predominantly. SMZL with monoclonal IgG is rarer.

PATIENT CONCERNS

We report a case of SMZL (49-year-old, male) with monoclonal IgG, MYD88L265P mutation and hepatitis B virus infection.

DIAGNOSES

The patient was presented to our hospital with aggravating complaints of dizziness, fatigue, postprandial abdominal distension, and night sweats. The diagnosis was confirmed by clinical manifestations, immunophenotype, bone marrow pathology.

INTERVENTIONS

The patient received rituximab-based chemotherapy and sequential ibrutinib in combination with entecavir.

OUTCOMES

After 1 year of follow-up, his blood routine examination had returned to normal with normal level of albumin and significantly lower globulin than before, and the spleen was of normal size.

LESSONS

We conclude that rituximab-based chemotherapy is the main treatment option for the patients with SMZL, and Bruton's tyrosine kinase inhibitor has also shown beneficial efficacy.

Lymphoma-Sink Effect in Marginal Zone Lymphoma Based on CXCR4-Targeted Molecular Imaging

PURPOSE

Recent studies investigating a tumor-sink effect in solid tumors reported on decreasing uptake in normal organs in patients with higher tumor burden. This phenomenon, however, has not been evaluated yet for theranostic radiotracers applied to hematological neoplasms. As such, we aimed to determine a potential "lymphoma-sink effect" in patients with marginal zone lymphoma (MZL) imaged with C-X-C motif chemokine receptor (CXCR) 4-directed PET/CTs.

PROCEDURES

We retrospectively analyzed 73 patients with MZL who underwent CXCR4-directed [⁶⁸Ga]Ga-PentixaFor PET/CT. Normal unaffected organ uptake (heart, liver, spleen, bone marrow, kidneys) was quantified using volumes of interests (VOIs) and mean standardized uptake values (SUV_mean) were derived. MZL manifestations were also segmented to determine the maximum and peak standardized uptake values SUV (SUV_max/peak) and volumetric parameters, including lymphoma volume (LV), and fractional lymphoma activity (FLA, defined as LV*SUV_mean of lymphoma burden). This approach resulted in 666 VOIs to capture the entire MZL manifestation load. We used Spearman's rank correlations to determine associations between organ uptake and CXCR4-expressing lymphoma lesions.

RESULTS

We recorded the following median SUV_mean in normal organs: heart, 1.82 (range, 0.78-4.11); liver, 1.35 (range, 0.72-2.99); bone marrow, 2.36 (range, 1.12-4.83); kidneys, 3.04 (range, 2.01-6.37); spleen, 5.79 (range, 2.07-10.5). No relevant associations between organ radiotracer uptake and MZL manifestation were observed, neither for SUV_max (ρ ≤ 0.21, P ≥ 0.07), SUV_peak (ρ ≤ 0.20, P ≥ 0.09), LV (ρ ≤ 0.13, P ≥ 0.27), nor FLA (ρ ≤ 0.15, P ≥ 0.33).

CONCLUSIONS

Investigating a lymphoma-sink effect in patients with hematological neoplasms, we observed no relevant associations between lymphoma burden and uptake in normal organs. Those observations may have therapeutic implications, e.g., for "cold" SDF1-pathway disrupting or "hot," CXCR4-directed radiolabeled drugs, as with higher lymphoma load, normal organ uptake seems to remain stable.

Lymphoplasmacytic lymphoma and marginal zone lymphoma involving bone marrow: A diagnostic dilemma. Useful clinicopathological features to accurate the diagnosis

Lymphoplasmacytic lymphoma (LPL) and marginal zone lymphoma (MZL) frequently infiltrate the bone marrow with similar histologic and immunohistochemical characteristics posing diagnostic problems. Bone marrow biopsy specimens from 25 LPL and 16 MZL have been studied, correlating with clinical, laboratory parameters and the MYD88_p.L265P mutation. Paratrabecular and interstitial infiltration pattern, serum IgM paraprotein levels, and MYD88_p.L265P mutation were significantly more frequent in LPL. Nodular or intrasinusoidal pattern with lymphocytosis and splenomegaly were associated with MZL diagnosis. Different clinical and histological parameters should be collected when LPL or MZL is suspected in bone marrow biopsy specimens.

Atypical Presentation of Marginal Zone Lymphoma as Isolated Diffuse Bone Marrow Involvement: Utility of F-18 FDG PET/CT in Diagnosis and Response Assessment

Non-Hodgkin's lymphoma (NHL) with secondary bone marrow involvement is relatively common. However, isolated involvement of bone marrow in marginal zone type of NHL is atypical and rare. Here, we describe a patient of atypical marginal zone lymphoma with isolated bone marrow involvement who presented with weight loss and bicytopenia, where F-18 FDG PET/CT (fluorine-18-labeled fluorodeoxyglucose positron emission tomography with computed tomography) imaging played a pivotal role in establishing the diagnosis when conventional imaging modalities were unremarkable. The patient was successfully treated with systemic chemotherapy (rituximab, cyclophosphamide, prednisolone) and achieved complete remission, as demonstrated by a follow-up F-18 FDG PET/CT scan.

Myeloid Nuclear Differentiation Antigen (MNDA): an aid in differentiating lymphoplasmayctic lymphoma and splenic marginal zone lymphoma in bone marrow biopsies at presentation

The differential diagnosis between lymphoplasmacytic lymphoma (LPL) and marginal zone B-cell lymphoma, particularly splenic type (SMZL) can be challenging on onset bone marrow biopsy (BMB) since morphology and phenotype are not specific and clinical features can overlap or be mildly developed at diagnosis. The LPL-specific L265P mutation in the MYD88 gene is not available in all laboratories and genetic aberrancies identified in SMZL (del7q, mutations of NOTCH2 and KLF2) are seldom searched in routine practice. The study aim is to investigate the potential role of MNDA expression in this specific differential diagnosis. We report MNDA reactivity in 559 small B-cell lymphoma (SBCL) patients including bone marrow biopsies from 90 LPL and 91 SMZL. MYD88 p.Leu265Pro mutation status was assessed and confirmed as positive in 24 of 90 LPL cases, which served as the test set. MNDA staining was negative in 23/24 LPL cases in the test set (96%). In the 157 remaining cases (66 LPL, 91 SMZL), which served as validation set, the MYD88 p.Leu265Pro mutation was unavailable and MNDA was more frequently expressed in SMZL (p<0.00001). In addition, immunohistochemical features more consistent with SMZL (i.e. presence of CD23+ follicular dendritic cell meshworks, polytypic plasma cells, DBA44 reactivity) were more often present in MNDA positive cases (statistically significant for 2 such parameters). On the widest case-series so far published focusing on LPL and SMZL immunohistochemical diagnosis at onset on BMB, we demonstrated that MNDA expression significantly support the diagnosis of SMZL. This observation may be of particular help in cases where the MYD88 p.Leu265Pro mutational status and/or SMZL-related genetic aberrations are unavailable.

Transformed diffuse large B-cell lymphoma from marginal zone lymphoma in the anterior mediastinum: A case report and review of the literature

Marginal zone lymphoma (MZL) arising from the anterior mediastinum is rare. In the majority of reported cases, the tumor was incidentally discovered, reflecting its indolent clinical features. We present a 38-year-old woman who had no medical history, and presented with a bulky anterior mediastinal tumor complicated by life-threatening compression of the vasculature and bronchi. Biopsy specimens of the neoplasm suggested transformed diffuse large B-cell lymphoma (DLBCL) from MZL. To our best knowledge, this is the first case report of anterior mediastinum MZL associated with an aggressive clinical course and life-threatening complications likely due to transformation to DLBCL.

CD5 expression in marginal zone lymphoma predicts differential response to rituximab or bendamustine/rituximab

We examined outcomes of 244 patients with marginal zone lymphoma (MZL) diagnosed in 2010-2020, of which 25 (10%) expressed CD5. CD5 expression was present in 22% of splenic, 8% of nodal, and 5% of extranodal MZL, and showed frequent blood/bone marrow involvement, elevated lactate dehydrogenase, and TP53 deletions. CD5 expression was not associated with progression-free or overall survival, but it conferred a significantly higher risk of histologic transformation (22% versus 4% at 5 years, p = 0.002). Among patients receiving first-line rituximab monotherapy, CD5 expression was associated with lower response rate (30% versus 77%, p = 0.006), PFS (25% versus 45% at 3 years, p = 0.003) and OS (44% versus 77%, p = 0.010), whereas CD5 status did not significantly affect outcomes of patients receiving bendamustine with rituximab (P for interaction = 0.012 for progression-free survival). CD5-positive MZL may have a propensity to leukemic dissemination, histologic transformation, and may derive benefit from first-line bendamustine/rituximab rather than rituximab alone.

Refractoriness to rituximab-based therapy and elevated serum B2-microglobulin predict for inferior survival in marginal zone lymphoma

Short responses to immunochemotherapy predict for an inferior OS in follicular lymphoma. We set out to determine whether this is also the case in marginal zone lymphoma. A group of 139 marginal zone lymphoma (MZL) patients treated with front-line immuno- or immunochemotherapy (I/ICT) were categorized into I/ICT-refractory (non-response or relapse/progression within six months of treatment response assessment) or I/ICT-sensitive. Twenty-three patients (17%) were refractory. Refractory patients had inferior OS (4-yr probabilities of 57% vs. 83%, p = .0003) as did those with beta2-microglobulin (B2M)>3 mg/L (4-yr probabilities of 80% vs. 100%, p = .0029). On multivariable analysis they both showed a borderline significant correlation with OS (p = .06 and .07, respectively). B2M > 3 mg/L was also an adverse prognostic factor for progression-free survival in both univariable (4-yr probability of 61% vs. 83%, p = .02) and multivariable analysis (HR 2.9, p = .02). In conclusion, B2M and refractoriness to I/ICT may identify patients with MZL at higher risk of inferior survival.

Management of relapsed/refractory marginal zone lymphoma: focus on ibrutinib

Marginal zone lymphomas (MZLs) consist of a diverse family of malignancies, which are derived from B-cells. The disease subtypes are recognized extranodal, nodal, and splenic MZLs. The disease characteristics, clinical course, and treatment vary considerably based on the site of involvement. In 2017, the US Food and Drug Administration approved ibrutinib, a first in class Bruton’s tyrosine kinase inhibitor that revolutionized the care of chronic lymphocytic leukemia patients; for, the treatment of relapsed/refractory MZL based on pivotal open-label Phase II trial demonstrated an overall response rate of 48%, with a complete response rate of 3%, median progression-free survival of 14.2 months, and median overall survival not yet reached at a median follow-up of 19.4 months. In this review, we aim to summarize the current conundrums in the management of MZL and the evolving role of ibrutinib in the treatment of MZL.

First-line treatment with bendamustine and rituximab, in patients with intermediate-/high-risk splenic marginal zone lymphomas

Splenic marginal zone lymphomas (SMZLs) are rare indolent B cell neoplasms that affect the spleen, bone marrow, and blood. Although they have an indolent course in the majority of patients, who have a median survival of 8-10 years, ∼ 30% may experience a worse outcome. The prognostic criteria of progression are lymph node and extra-nodal involvement, high lymphocyte counts, anaemia, and thrombocytopenia. The treatment of SMZLs include a "wait and watch strategy", splenectomy, and alkylating agents ± rituximab. We here describe data relating to 70 patients with intermediate-/high-risk SMZLs, who received rituximab/bendamustine as first-line treatment for a median of 60 days (range 1-75) after diagnosis. Sixty patients (86%) achieved a complete response (CR), and seven (10%) a partial response (PR). Three patients (4.3%) experienced disease progression (PD). The median duration of remission was 18 months. Side effects were generally mild. Our findings suggest that rituximab/bendamustine is a feasible treatment option in patients with intermediate-/high-risk SMZLs.

Splenic marginal zone lymphoma: from genetics to management

Splenic marginal zone lymphoma (SMZL) is a rare B-cell malignancy involving the spleen, bone marrow, and frequently the blood. SMZL lymphomagenesis involves antigen and/or superantigen stimulation and molecular deregulation of genes (NOTCH2 and KLF2) involved in the physiological differentiation of spleen marginal zone B cells. Diagnosis requires either spleen histology or, alternatively, the documentation of a typical cell morphology and immunophenotype on blood cells coupled with the detection of intrasinusoidal infiltration by CD20+ cells in the bone marrow. Among B-cell tumors, deletion of 7q and NOTCH2 mutations are almost specific lesions of SMZL, thus representing promising diagnostic biomarkers of this lymphoma. Although the majority of SMZLs show an indolent course with a median survival of approximately 10 years, nearly 30% of patients experience a poor outcome. No randomized trials are reported for SMZL, and few prospective trials are available. A watch-and-wait approach is advisable for asymptomatic patients. Treatment options for symptomatic patients ranges from splenectomy to rituximab alone or combined with chemotherapy. In some geographic areas, a subset of patients with SMZL associates with hepatitis C virus infection, prompting virus eradication as an effective lymphoma treatment. It would be worthwhile to explore deregulated cellular programs of SMZL as therapeutic targets in the future; improved clinical and biological prognostication will be essential for identifying patients who may benefit from novel approaches.

Discordant bone marrow involvement in non-Hodgkin lymphoma

A discordant lymphoma occurs where 2 distinct histologic subtypes coexist in at least 2 separate anatomic sites. Histologic discordance is most commonly observed between the bone marrow (BM) and lymph nodes (LNs), where typically aggressive lymphoma is found in a LN biopsy with indolent lymphoma in a BM biopsy. Although the diagnosis of discordance relied heavily on histopathology alone in the past, the availability of flow cytometry and molecular studies have aided the identification of this entity. The true prevalence and clinical ramifications of discordance remain controversial as available data are principally retrospective, and there is therefore little consensus to guide optimal management strategies. In this review, we examine the available literature on discordant lymphoma and its outcome, and discuss current therapeutic approaches. Future studies in discordant lymphoma should ideally focus on a large series of patients with adequate tissue samples and incorporate molecular analyses.

Vanishing bile duct syndrome and immunodeficiency preceding the diagnosis of Hodgkin lymphoma

Vanishing bile duct syndrome (VBDS) in association with Hodgkin lymphoma (HL) is well described but not well understood. We report an unusual case of a 75-year-old patient presenting with biopsy-proven VBDS and immunodeficiency, without identifiable cause, which showed a waxing and waning course, culminating in the development of HL 18 months later. To our knowledge, this is the first adult case in which VBDS preceded the diagnosis of HL by such a long period.

Recognizing nodal marginal zone lymphoma: recent advances and pitfalls. A systematic review

The diagnosis of nodal marginal zone lymphoma is one of the remaining problem areas in hematopathology. Because no established positive markers exist for this lymphoma, it is frequently a diagnosis of exclusion, making distinction from other low-grade B-cell lymphomas difficult or even impossible. This systematic review summarizes and discusses the current knowledge on nodal marginal zone lymphoma, including clinical features, epidemiology and etiology, histology, and cytogenetic and molecular features. In particular, recent advances in diagnostics and pathogenesis are discussed. New immunohistochemical markers have become available that could be used as positive markers for nodal marginal zone lymphoma. These markers could be used to ensure more homogeneous study groups in future research. Also, recent gene expression studies and studies describing specific gene mutations have provided clues to the pathogenesis of nodal marginal zone lymphoma, suggesting deregulation of the nuclear factor kappa B pathway. Nevertheless, nodal marginal zone lymphoma remains an enigmatic entity, requiring further study to define its pathogenesis to allow an accurate diagnosis and tailored treatment. However, recent data indicate that it is not related to splenic or extranodal lymphoma, and that it is also not related to lymphoplasmacytic lymphoma. Thus, even though the diagnosis is not always easy, it is clearly a separate entity.

Bone marrow stroma CD40 expression correlates with inflammatory mast cell infiltration and disease progression in splenic marginal zone lymphoma

Splenic marginal zone lymphoma (SMZL) is a mature B-cell neoplasm characterized by rather indolent clinical course. However, nearly one third of patients experience a rapidly progressive disease with a dismal outcome. Despite the characterization of clone genetics and the recognition of deregulated immunologic stimulation in the pathogenesis of SMZL, little is known about microenvironment dynamics and their potential biological influence on disease outcome. Here we investigate the effect of stroma-intrinsic features on SMZL disease progression by focusing on the microenvironment of the bone marrow (BM), which represents an elective disease localization endorsing diagnostic and prognostic relevance. We show that the quality of the BM stromal meshwork of SMZL infiltrates correlates with time to progression. In particular, we describe the unfavorable prognostic influence of dense CD40 expression by BM stromal cells, which involves the contribution of CD40 ligand (CD40L)-expressing bystander mast cells infiltrating SMZL BM aggregates. The CD40/CD40L-assisted crosstalk between mesenchymal stromal cells and mast cells populating the SMZL microenvironment finds correlation in p53(-/-) mice developing SMZL and contributes to the engendering of detrimental proinflammatory conditions. Our study highlights a dynamic interaction, playing between nonneoplastic elements within the SMZL niche, toward disease progression.

Bone marrow trephine biopsy involvement by lymphoma: review of histopathological features in 511 specimens and correlation with diagnostic biopsy, aspirate and peripheral blood findings

AIMS

This study aimed to evaluate the key features of bone marrow trephine (BMT) biopsy involvement by lymphoma.

METHODS

511 cases were assessed for percentage of marrow involvement, pattern of involvement (diffuse, nodular, paratrabecular, interstitial or intrasinusoidal), presence/absence of granulomas, stromal fibrosis and necrosis, presence/absence of neoplastic/reactive follicles and discordance with other biopsy sites. Correlation with aspirate and peripheral blood findings was made in a subset of 345 patients (167 aspirates, 178 blood).

RESULTS

The most frequent subtype was follicular lymphoma (26.2%) followed by extranodal marginal zone (23.1%), lymphoplasmacytic (19.2%), diffuse large B cell (DLBCL) (12.5%), Hodgkin (HL) (5.7%) and mantle cell lymphomas (4.3%). The predominant pattern in follicular lymphoma was paratrabecular. Marginal zone lymphomas of all types and lymphoplasmacytic lymphoma showed a relatively even distribution between diffuse, interstitial, paratrabecular and nodular patterns. The majority of mantle cell lymphoma cases showed either diffuse or nodular patterns. A diffuse pattern was common in DLBCL and Burkitt lymphomas. An intrasinusoidal pattern was seen only in extranodal and splenic marginal zone lymphomas. Granulomas and fibrosis were uncommon in small cell B cell lymphomas but frequent in DLBCL and HL. Aspirate and trephine results concurred in 73.8% of cases overall, but this varied widely between subtypes. Peripheral blood involvement rates by lymphoma also varied, with a mean of 37.1%.

CONCLUSIONS

Different lymphomas often demonstrate reliably characteristic architectural patterns of marrow involvement which can help differentiate them even when cytological features do not permit this, and marrow stromal and other background changes may also be useful pointers towards a particular lymphoma subtype.

Splenic marginal zone B-cell lymphoma: a distinct clinicopathological and molecular entity. Recent advances in ontogeny and classification

PURPOSE OF REVIEW

Indolent B-cell lymphomas that are supposed to derive from marginal zone encompass three distinct entities: extranodal marginal zone lymphoma (MZL) or mucosa-associated lymphatic tissue (MALT), nodal MZL (NMZL) and splenic MZL (SMZL). Although MALT lymphoma is well characterized and extensively studied at the clinical and molecular levels, SMZL and NMZL remain incompletely characterized. However, during the last years, the clinical and molecular heterogeneity of SMZL has been clarified. The recent 2008 WHO classification has maintained the distinction between the three diseases according to the organ where it arises and introduced a new provisional category of unclassified splenic lymphoma for overlapping entities, splenic diffuse red pulp lymphoma (SDRPL) and hairy cell leukemia-variant (HCL-V).

RECENT FINDINGS

Recent findings in SMZL contributed to a better characterization, including the few cases associated with hepatitis C, the recurrence of 7q deletion and the possibility of CD5 expression. Furthermore, the peculiar pattern of immunoglobulin heavy chain genes mutations and the biased usage of immunoglobulin heavy chain variable region genes (IGHV)1-2 segment are suggestive of a T-independent antigen driven proliferation, at least at initial steps. This review will focus on recent findings and differential diagnosis with SDRPL and HCL-V.

SUMMARY

The conjunction of morphologic, cytogenetic and clinical data has increased diagnosis reproducibility.

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.

The many faces of marginal zone lymphoma

Indolent B-cell lymphomas that are supposed to derive from the marginal zone (marginal zone lymphomas [MZLs]) include 3 specific entities: extranodal marginal zone lymphoma (EMZL) or mucosa-associated lymphatic tissue (MALT) lymphoma, splenic MZL (SMZL), and nodal MZL (NMZL). The clinical and molecular characteristics are different for each entity, with some shared phenotypic and genetic features. EMZL is the most common entity, accounting for approximately 70% of all MZLs. These neoplasms can arise at virtually any extranodal site and are commonly associated with chronic antigenic stimulation either as a result of infection (eg, Helicobacter pylori in the stomach) or autoimmune disease (eg, Sjögren syndrome and salivary glands). Several chromosomal translocations were also identified in EMZL, accounting in the aggregate for approximately one-third of all cases. SMZL accounts for approximately 20% of all MZLs. Patients typically present with an enlarged spleen and involvement of abdominal lymph nodes and BM. Approximately 40%-50% of SMZLs are associated with deletions of chromosome 7q. NMZL is the less common entity, representing approximately 10% of all MZLs. Patients with NMZL, by definition, have lymph node–based disease without involvement of the spleen or extranodal sites. The molecular pathogenesis of NMZL is still unknown.

Absence of TCL1A expression is a useful diagnostic feature in splenic marginal zone lymphoma

Splenic marginal zone lymphoma (SMZL) is a low-grade lymphoma showing a rather nonspecific immunophenotype. Gene expression profiling studies suggested that TCL1A could be a marker of SMZL, but reported data are conflicting. We evaluated TCL1A expression in a series of spleen and bone marrow samples involved by SMZL and correlated the findings with other immunophenotypical, morphological, and clinical data. In addition, we evaluated the expression of TCL1A in a series of spleens and lymph nodes involved by lymphomas that might mimic SMZL (13 nodal marginal zone lymphomas (NMZL), 39 follicular lymphomas (FL), 30 B-cell chronic lymphocytic leukemias (B-CLL), 31 mantle cell lymphomas (MCL), 1 lymphoplasmacytic lymphoma) and 15 bone marrow specimens involving hairy cell leukemia (HCL). TCL1A staining was negative in 24/31 cases of SMZL (77 %); 27/31 MCL and all B-CLL were positive for TCL1A; 32/34 cases of nodal FL (96 %) and all five splenic FL were positive for TCL1A, although at a lower intensity. Eight of 13 NMZL were positive for TCL1A, often showing a heterogeneous staining pattern. All HCL samples were strongly positive for TCL1A. No correlation was found between the pattern of splenic infiltration, TCL1A expression, and the clinical course. TCL1A-positive SMZL showed a higher rate of DBA44 staining compared to the negative ones, and this difference was statistically significant (Fisher test, single-tailed, p = 0.0397). Our data support the use of TCL1A in the panel of diagnostic markers used in the differential diagnosis of splenic low-grade B-cell lymphoma; a possible prognostic value, however, needs a larger series to be established.

Non-MALT marginal zone lymphoma

PURPOSE OF REVIEW

Non-MALT marginal zone lymphoma regroups two subtypes of lymphoma, the splenic marginal zone lymphoma (SMZL) and the nodal marginal zone lymphoma (NMZL). Although they share a common cell of origin from the 'marginal zone', they display different clinical characteristics, reflecting probable biological variations according to the organ.

RECENT FINDINGS

Within the past decade, new data regarding pathogenic mechanisms as well as therapeutic advances have been reported.

SUMMARY

SMZL and NMZL often present with disseminated disease at diagnosis, with specific clinical presentation, SMZL with predominant enlarged splenomegaly and NMZL with disseminated nodal involvement. Diagnosis may be difficult among the small B-cell lymphomas and criteria for diagnosis have been recently improved. The therapeutic approaches comprise splenectomy for SMZL, and immunochemotherapy for both of SMZL and NMZL, but with no consensus about the best treatment, except when associated with hepatitis C virus. This review addresses the current knowledge on the biological findings, clinical features and therapeutic approaches for the individual SMZLs and NMZLs.

Distinctive clinical and histological features of Waldenström's macroglobulinemia and splenic marginal zone lymphoma

We studied 122 patients with Waldenström's macroglobulinemia (WM) and 98 with splenic marginal zone lymphoma (SMZL); 29 SMZL patients (30%) had a serum MC (IgM in 17 patients). SMZL differed from WM for female prevalence, abdominal and superficial adenopathy, spleen and liver involvement, positive HCV. The median MC level was 2.0 g/dL in WM and 0.95 g/dL in SMZL (P<.001). On BM histology, SMZL was characterized by sinusoidal infiltration (70% of cases) and by a more frequent nodular pattern (P<.01) while WM had a higher incidence of interstitial BM localization. After a median follow-up of 5.3 years, median OS was not reached for SMZL and was 12 years for WM (P=.23; 14 years for asymptomatic WM, 8 years for symptomatic WM). In conclusion, despite similar outcomes of these 2 entities, SMZL appears as a disease with distinct clinical features and BM histology and a peculiar association with HCV infection.

Prognostic factors in low-grade non-Hodgkin lymphomas

Low-grade non-Hodgkin lymphomas were once considered as a heterogenous group of lymphomas characterized by an indolent clinical course. Today, low-grade non-Hodgkin lymphomas are classified as a group of 10 distinct entities, each characterized by unique clinico biologic features. Follicular lymphoma, chronic lymphocytic leukemia/small lymphocytic lymphoma, lymphoplasmacytic lymphoma, and marginal zone lymphoma are the most-investigated subtypes. Several studies have been performed to identify prognostic factors specific for each subtype in an effort to help clinicians in treatment decisions. The field of biologically specific associated parameters holds great potential but requires more research and work to produce translational results.

Diagnosis and staging in gastrointestinal lymphoma

The diagnosis gastrointestinal lymphoma can be made on endoscopic biopsies in the vast majority of cases. Definitive subtyping of the lymphoma according to the WHO classification with the use of additional immunological and molecular markers is the cornerstone for further decision making. Several lymphomas may occur multifocally or show both small cell and large cell components. Therefore, a second endoscopy with an extensive biopsy protocol (mapping) may be mandatory. Staging procedures are required for therapeutic decision making and should include CT-scan, laboratory studies and bone marrow examination as required in other lymphomas. Additional studies must be performed depending subtype and localisation of the lymphoma. In gastric lymphoma endosonography reveals prognostic information. In marginal zone lymphoma of MALT-type attention to other MALT-sites and autoimmune diseases is necessary. In enteropathy-associated T-cell lymphoma screening for coeliac disease and enteroscopy are required. In several lymphomas (diffuse large B-cell lymphoma and mantle cell lymphoma) a PET-scan is considered as standard of care. The value of staging procedures after treatment is less well defined. At least in gastric lymphomas, histology is the gold standard after treatment and during follow-up.

Subcutaneous 'lipoma-like' B-cell lymphoma associated with HCV infection: a new presentation of primary extranodal marginal zone B-cell lymphoma of MALT

BACKGROUND

Hepatitis C virus (HCV) infection has been linked to lymphoproliferative disorders. Marginal zone B-cell lymphoma (MZL) represents one of the most frequent lymphoma subtypes associated with HCV infection. We describe an unusual subset of HCV-associated MZL characterized by subcutaneous presentation.

MATERIALS AND METHODS

A series of 12 HCV-positive patients presenting with subcutaneous nodules that revealed lymphoma infiltration at biopsy. Molecular analysis of immunoglobulin heavy chain (IGH) gene rearrangement and FISH investigations for t(11;18)(q21;q21) and t(14;18)(q32;q21) were carried out in nine patients.

RESULTS

The 12 patients (median age 69.5 years), all with positive HCV serology, presented with single or multiple subcutaneous nodules resembling lipomas. Histologically the lesions showed lymphoid infiltrates, consistent with extranodal MZL of mucosa-associated lymphoid tissue (MALT). Functional IGH gene rearrangements were identified in nine tested patients, with somatic mutations in 82%, indicating a histogenesis from germinal center-experienced B cells. The t(11;18) was found in two of nine cases. Staging did not show any other lymphoma localization. In two patients, a response was achieved with antiviral treatment. Extracutaneous spread to MALT sites occurred in a case.

CONCLUSIONS

Our observations expand the spectrum of HCV-associated lymphomas to include a subset of extranodal MZL characterized by a novel primary 'lipoma-like' subcutaneous presentation and indolent clinical course.

Splenectomy with chemotherapy vs surgery alone as initial treatment for splenic marginal zone lymphoma

AIM: To evaluate the clinical characteristics of splenic marginal-zone lymphoma (SMZL) following antigen expression and the influence of therapeutic approaches on clinical outcome and overall survival (OS).

METHODS: A total of 30 patients with typical histological and immunohistochemical SMZL patterns were examined. Splenectomy plus chemotherapy was applied in 20 patients, while splenectomy as a single treatment-option was performed in 10 patients. Prognostic factor and overall survival rate were analyzed.

RESULTS: Complete remission (CR) was achieved in 20 (66.7%), partial remission (PR) in seven (23.3%), and lethal outcome due to disease progression occurred in three (10.0%) patients. Median survival of patients with a splenectomy was 93.0 mo and for patients with splenectomy plus chemotherapy it was 107.5 mo (Log rank = 0.056, P > 0.05). Time from onset of first symptoms to the beginning of the treatment (mean 9.4 mo) was influenced by spleen dimensions, as measured by computerized tomography and ultra-sound (t = 2.558, P = 0.018). Strong positivity (+++) of CD20 antigen expression in splenic tissue had a positive influence on OS (Log rank = 5.244, P < 0.05). The analysis of factors interfering with survival (by the Kaplan-Meier method) revealed that gender, general symptoms, clinical stage, and spleen infiltration type (nodular vs diffuse) had no significant (P > 0.05) effects on the OS. The expression of other antigens (immunohistochemistry) also had no effect on survival-rate, as measured by a χ² test (P > 0.05).

CONCLUSION: Initial splenectomy combined with chemotherapy has been shown to be beneficial due to its advanced remission rate/duration; however, a larger controlled clinical study is required to confirm our findings.