Marginal zone cell lymphoma--an update on recent advances

Morphological and immunohistochemical approaches to the diagnosis of Hashimoto thyroiditis and mucosa associated lymphoid tissue lymphomas: An audit

Most cases of autoimmune hypothyroidism are due to Hashimoto thyroiditis (HT). It is sometimes difficult to distinguish HT from mucosa associated lymphoid tissue (MALT) lymphoma using cytology or histology alone. This has necessitated the use of immunohistochemistry and other molecular techniques. A descriptive study was undertaken to determine the prevalence of MALT lymphoma and other associations of HT using histopathological and immunohistochemical methods. For testing of kappa and lambda antibodies, paraffin sections were prepared for immunohistochemical staining using a peroxidase-antiperoxidase immune complex method. Immunostaining in HT, demonstrated a polyclonal lymphoid population, as evidenced by dual positivity for kappa and lambda staining cells, whereas MALT lymphoma revealed a monoclonal lymphoid population, with strong positivity for kappa immunostaining and lack of lambda light chain expression. The proportion of MALT lymphoma in surgically treated cases of HT in the present study was 3.5% (95% CI: 0%–8.3%). The common malignancy associated with HT was papillary carcinoma of the thyroid (8.8%). Among the benign conditions, nodular colloid goiter (7%) was more commonly associated. Although modern molecular techniques are available for the confirmation of lymphomas, they are more expensive, time consuming and are available only in a few centers. Strict morphological criteria can differentiate HT from MALT lymphoma, but in suspicious cases, paraffin section immunohistochemistry using light chain restriction can offer comparable and reliable results. Since papillary carcinoma and MALT lymphoma have been associated with HT, these patients require careful surveillance.

Marginal Zone Lymphoma: State-of-the-Art Treatment

OPINION STATEMENT

Despite being the second most common indolent non-Hodgkin's lymphoma (iNHL), marginal zone lymphoma (MZL) remains largely understudied, and given its underlying disease heterogeneity, it is challenging to define a single treatment approach for these patients. For localized disease, local therapy is recommended such as triple therapy for H. pylori in gastric extranodal MZL, splenectomy for splenic MZL, and radiotherapy for nodal MZL. For disseminated disease with low tumor burden, a watch and wait or single-agent rituximab can be used. However, for symptomatic disease, a similar approach to follicular lymphoma (FL) can be used with chemoimmunotherapy approaches such as bendamustine and rituximab. High FDG uptake is not common in MZL and is not diagnostic by itself of transformation to high-grade lymphoma but informs the choice of the site to be biopsied. Transformation into a large B cell lymphoma is treated with R-CHOP-like regimens. Patients with relapsing disease after at least one CD20-based therapy have several recently approved chemotherapy-free options including B cell receptor inhibitors such ibrutinib (approved specifically in MZL) and immunomodulatory agents such as lenalidomide and rituximab (FDA approved in MZL and FL). Phosphoinositide 3-kinase (PI3K) inhibitors have shown excellent activity in iNHL, specifically in MZL, with breakthrough designation status for copanlisib and umbralisib, allowing off label use of this class of agents in clinical practice. With the availability of prospective clinical trials using chemo-free approaches, specifically those targeting abnormal signaling pathways activated in MZL tumors and its microenvironment, treating physicians are encouraged to enroll patients on these clinical trials in order to better understand the underlying biology, mechanisms of response, and resistance to current therapies and help design future rationale combination strategies.

A Rare Case of Composite Dural Extranodal Marginal Zone Lymphoma and Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma

Background

Primary extranodal marginal zone lymphoma (MZL) of the dura is a rare neoplastic entity in the central nervous system (CNS).

Methods

We used literature searches to identify previously reported cases of primary dural MZL. We also reviewed clinical, pathologic, and radiographic data of an adult patient with concurrent dural MZL and chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL).

Results

We identified 104 cases of dural MZL in the literature. None of them presented concurrently with another type of non-Hodgkin lymphoma. This is the first report of composite lymphoma consisting of dural MZL and CLL/SLL in the bone marrow and lymph nodes.

Conclusion

Primary dural MZL is a rare, indolent low-grade CNS lymphoma, with a relatively good prognosis. Its treatment is multidisciplinary and often requires surgical intervention due to brain compression, along with low to moderate doses of radiotherapy and/or systemic chemotherapy.

Epidemiology and environmental aspects of marginal zone lymphomas

Marginal zone lymphomas (MZLs) account for between 5% and 17% of all non-Hodgkin's lymphomas. MZLs consist of 3 different subtypes with extranodal being the most commonly reported, representing 50-70% of MZL, followed by splenic (20%) and nodal (10%). Median age at presentation varies between these lymphoma sub-types, ranging between 50 and 69 years, with an overall greater incidence noted in males compared to females. Given the rarity of these lymphomas, epidemiologic data has been sparse, although it has been suggested the aetiology is multi-factorial including ethnicity and geographical factors. Other reported associations include autoimmune disease and infection, with Helicobacter pylori and Campylobacter psittaci, being the most commonly reported pathogens. Larger population studies are required to investigate the role of these environmental factors further as these can direct the future management of these lymphomas, through the use of more effective targeted treatments.

Splenic marginal zone lymphoma: An indolent malignancy leading to the development of neurolymphomatosis

INTRODUCTION

Acute neuropathic pain and weakness with a sensory level in a patient with a history of lymphoma has a broad differential diagnosis. Evaluation of such a presentation often includes MRI, neurophysiologic studies, and cerebrospinal fluid evaluation. We report a patient with splenic marginal zone lymphoma who developed acute weakness, sensory loss, and neuropathic pain due to neurolymphomatosis.

METHODS

Clinical evaluation, MRI of the lumbar spine, cerebrospinal fluid evaluation, electrodiagnostic (EDx) studies, and biopsy of a dorsal nerve root were undertaken.

RESULTS

EDx studies were consistent with an acute, acquired demyelinating sensorimotor polyradiculoneuropathy. Treatment with intravenous immunoglobulin and plasma exchange did not lead to clinical improvement. Ultimately, biopsy of a dorsal nerve root was performed and revealed neurolymphomatosis.

CONCLUSION

This case emphasizes that, when it can be performed safely, biopsy for suspected neurolymphomatosis is imperative for appropriate diagnosis and treatment. Muscle Nerve 55: 440-444, 2017.

PET/Computed Tomography in the Diagnosis and Staging of Gastric Cancers

Although there has been a reduction of the incidence and mortality of gastric cancer, it remains among the commonest causes of cancer-related death. Accurate staging and evaluation of treatment response are vital for management. PET is used to complement anatomic imaging in cancer management. PET/computed tomography (CT) has demonstrated its potential value for preoperative staging, evaluation of response to therapy, and detection of recurrence. Not all types of gastric cancers have a high affinity for fluorodeoxyglucose. PET/CT in the evaluation and staging of gastric cancer is not established, but studies indicate that there may be an evolving role for this imaging modality.

Role of molecular studies in the classification of lymphoma

The classification of lymphomas has historically lacked both precision and accuracy, potentially compromising both optimal diagnosis and therapy. The genetic characterization of key oncogenic events and the advent of expression profiling have afforded the opportunity to understand, diagnose and treat these diseases in a much more rational and targeted manner. As exciting as these new and testable data are, it is also worth noting that molecular genetic analysis of the tumor in isolation will not be the sole arbiter of patient outcome. It is likely that we will remain reliant on traditional and sometimes subjective technologies, albeit probably to a lesser degree, with molecular studies significantly complementing, but certainly not replacing, microscopic, immunophenotypic and cytogenetic approaches. Furthermore, we will perhaps need to extend genotyping to the tumor milieu (the patient) in order to molecularly dissect drug metabolic pathways and the immune response.

SUVmax/THKmax as a biomarker for distinguishing advanced gastric carcinoma from primary gastric lymphoma

Background

Gastric carcinoma and primary gastric lymphoma (PGL) are the two most common malignancies in stomach. The purpose of this study was to screen and validate a biomarker of ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) for distinguishing advanced gastric carcinoma (AGC) from PGL for clinical applications.

Methodology/Principal Findings

We reviewed PET/CT scans collected from January 2008 to April 2012 of 69 AGC and 38 PGL (14 low-grade mucosa-associated lymphoid tissue [MALT], 24 non-MALT aggressive non-Hodgkin lymphoma [ANHL]) with a focus on FDG intensity (maximum standardized uptake value [SUVmax]) of primary lesions and its CT-detected abnormalities, including maximal gastrointestinal wall thickness (THKmax) and mucosal ulcerations. Gastric FDG uptake was found in 69 (100%) patients with AGC and 36 (95%, 12 MALT vs. 24 ANHL)with PGL. The presence of CT-detected abnormalities of AGC and PGL were 97% (67/69) and 89% (12 MALT vs. 22 ANHL), respectively. After controlling for THKmax, SUVmax was higher with ANHL than AGC (17.10±8.08 vs. 9.65±5.24, p<0.05) and MALT (6.20±3.60, p<0.05). THKmax did not differ among MALT, ANHL and AGC. Mucosal ulceration was more common with AGC (n = 9) than PGL (n = 2),but the difference was not statistically significant (p>0.05). Cross-validation analysis showed that for distinguishing ANHL from AGC, the classifier with SUVmax as a feature achieved a correct classification rate of 81% with thresholds 13.40±1.12 and the classifier with SUVmax/THKmax as a feature achieved a correct classification rate of 83% with thresholds 7.51±0.63.

Conclusions/Significance

SUVmax/THKmax may be as a promising biomarker of FDG-PET/CT for distinguishing ANHL from AGC. Structural CT abnormalities alone may not be reliable but can help with PET assessment of gastric malignancies. ¹⁸F-FDG PET/CT have potential for distinguishing AGC from PGL at the individual level.

Primary gastric lymphoma: utility of 18F-fluorodeoxyglucose positron emission tomography-computed tomography for detecting relapse after treatment

The purpose of this study was to evaluate the role of 18F-fluorodeoxyglucose ((18)F-FDG) positron emission tomography-computed tomography (PET-CT) in detecting relapse in patients with primary gastric lymphoma (PGL) post-treatment. Data of 39 previously treated patients with PGL (age: 50.3 ± 13.8 years; male: 24) who underwent 71 (18)F-FDG PET-CT studies for suspected relapse (n = 53) or routine follow-up (n = 18) were retrospectively evaluated. PET-CT images were evaluated both qualitatively and quantitatively (standardized uptake value [SUVmax]). A combination of clinical/imaging follow-up, endoscopy and/or histopathology was taken as the reference standard. The per patient based sensitivity of PET-CT was 96%, specificity 91% and accuracy 93%. The lymph node was the commonest site of relapse on PET-CT. Mean lesion SUVmax was 5.9 ± 3.1 (2.3-13.6). Accuracy was similar in suspected relapse and routine follow-up groups (90.5% vs. 100%; p = 0.409). Based on the data, (18)F-FDG PET-CT appears to be highly accurate for the detection of relapse in patients with PGL post-treatment.

Extranodal diffuse large B cell lymphoma of cutaneous follicle centre lymphoma type: a study of 24 patients with non-cutaneous primary limited stage extranodal diffuse large B cell lymphoma in support of a new concept

AIMS

Follicle centre cell lymphoma of small cell type showing either a follicular or diffuse growth pattern similar to cutaneous follicle centre lymphoma (cFCL) has been recognized in extranodal non-cutaneous sites. Our aim was (i) to investigate whether diffuse large B cell lymphoma (DLBCL) of cFCL type could be identified in extranodal non-cutaneous sites and (ii) whether clinical characteristics similar to primary cFCL could be recognized.

METHODS AND RESULTS

Of 24 extranodal non-cutaneous DLBCLs, nine (38%) had large centrocytoid morphology and 15 (62%) were either 'centrocytoid and centroblastic' or 'centroblastic and immunoblastic'. Six centrocytoid cases were Irf-4 negative, Bcl-6 positive and at most weakly CD10- or Bcl-2-positive by immunohistochemistry, consistent with DLBCL of cFCL type. All patients with cFCL type were stage IE and were significantly younger than other patients. Recurrences occurred in two patients and were exclusively extranodal.

CONCLUSION

Our results suggest that DLBCL of cFCL type can be identified in extranodal non-cutaneous sites and shows clinical characteristics similar to genuine cFCL. We propose to expand the concept of cFCL to encompass large cell lymphomas in extranodal sites.

Imaging of extranodal lymphoma with PET/CT

Hodgkin disease (HD) and non-Hodgkin lymphoma (NHL) represent a spectrum of malignant neoplasms arising from the lymphoid system with an incidence of around 8% of all malignancies. Although they are generally known as tumors of lymph nodes, 25% to 40% of HD/NHL tumors, especially NHL, arise at extranodal sites along the gastrointestinal tract, head and neck, orbit, central and peripheral nervous system, thorax, bone, skin, breast, testis, thyroid, and genitourinary tract. Extranodal involvement is an important pretreatment prognostic factor for patients with lymphoma and its incidence has increased in the past 2 decades. Imaging plays an important role in the noninvasive pretreatment assessment of patients with extranodal lymphoma. This involvement can be subtle and may be overlooked during computed tomography (CT). Positron emission tomography/CT (PET/CT) has evolved into an important imaging tool for evaluation of lymphomas, facilitating the detection of affected extranodal sites even when CT shows subtle or no obvious lesions. Familiarity with extranodal manifestations and suggestive PET/CT features in different sites is important for accurate evaluation of lymphoma. This article reviews the extranodal PET/CT imaging findings regarding HD and NHL.

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.

Primary central nervous system mucosa-associated lymphoid tissue lymphoma: case report and literature review

Primary presentation of intradural non-Hodgkin lymphoma is rare. Recently, B-cell lymphomas of mucosa-associated lymphoid tissue (MALT) have been recognized as an important pathologic subtype. When MALT lymphomas present in the central nervous system (CNS), they are distinguishable from primary high-grade CNS lymphomas. We present the clinicopathologic features of 5 patients with primary CNS MALT lymphoma treated at our institution from 1999 to 2006. Four out of 5 patients were women, and all patients presented with headaches, focal motor deficits, or cranial nerve palsy. Radiologic studies demonstrated ill-defined dural masses in 3 and well-defined masses in 2 patients. Pathology revealed small to medium-sized cells with a moderate amount of cytoplasm and irregular nuclear borders, expressing pan B-cell markers (CD19, CD20, and CD79a) but lacking CD10, CD23, and cyclin D1, confirming low-grade MALT lymphoma. Plasma cells were encountered in all the biopsies with variable reactive T-cell infiltration. wedge chain restriction was seen in 3 patients. Therapy consisted of either surgical resection, whole-brain radiation, or systemic or intrathecal chemotherapy. There was no evidence of recurrence or systemic relapse in 4 patients at 4 years of follow-up. One patient died in 2 months, unrelated to CNS lymphoma. This case series illustrates the rare occurrence of low-grade dural B-cell lymphoma and the need to consider this entity in the differential diagnosis of CNS lesions.

Leukaemic Subtype of Marginal Zone Lymphoma: A Presentation of Three Cases and Literature Review

The recent World Health Organization (WHO) classification recognizes three subtypes of marginal zone lymphoma (MZL): extranodal MZL of mucosa-associated lymphoid tissue (MALT), splenic MZL and nodal MZL. As a group, MZL share morphological and immunophenotypic features similar to that of the marginal zone B-cell in secondary B-follicles, the postulated common cell of origin. There is, however, increasing information about molecular heterogeneity between the types of MZL, suggesting different aetiology and highlighting our current incomplete understanding of this evolving entity. We describe the presentation and clinical course of three patients with MZL who do not fit the currently recognized WHO categories, and best fit the putative category of MZL, leukaemic subtype. We review the current literature on this newly described entity, highlighting the importance of its recognition.

Marginal zone B-cell lymphoma: a retrospective immunophenotypic analysis

BACKGROUND

Marginal zone B-cell lymphoma (MZL) comprises three related yet biologically distinct subtypes--splenic MZL (SMZL), nodal MZL (NMZL), and extranodal MZL of MALT type (MALT). In cases without adequate morphology, immunophenotypic characterization by flow cytometric immunophenotyping (FCI) relies heavily on exclusion of other low-grade lymphomas. We performed a retrospective review of FCI studies of MZL to search for immunophenotypes specific for MZL and its subtypes. We compared these to follicular lymphoma (FL) as we were specifically interested in differentiating MZL from CD10 negative FL.

DESIGN

FCI findings for MZL and FL cases were reviewed. Statistical analysis of patterns and intensity of antigen expression [mean channel fluorescence (MCF)] were performed.

RESULTS

Thirty-one cases of MZL (7 SMZL, 6 NMZL, 15 MALT, 3 MZL not otherwise specified) and 31 cases of FL were identified. All expressed CD19, CD20, and CD45. Thirty-two percent of MZL and 77% of FL expressed CD38. Expression of CD11c was seen in 57% of SMZL and 8% of other MZL (P < 0.01). Statistically significant differences in antigen expression between MZL and FL were seen for CD10, CD11c, and CD38. CD19 expression was significantly brighter in MZL (mean MCF of 455.3) than in FL (mean MCF of 166.9) (P < 0.001). MCF for isotype controls and CD20 were similar for FL and MZL.

CONCLUSIONS

MZL expresses typical pan-B-cell antigens. Expression of CD11c is highly associated with SMZL. Levels of CD19 expression in conjunction with CD11c and CD38 expression can distinguish MZL from CD10 negative FL.

FDG avidity and PET/CT patterns in primary gastric lymphoma

PURPOSE

The use of 18F-fluoro-deoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) in primary gastric lymphoma (PGL) is challenging due to physiologic FDG activity in the stomach and variability in the degree of uptake in various histologic subtypes. This study assesses FDG avidity and PET/CT patterns in newly diagnosed PGL.

METHODS

Sixty-two PET/CT studies of newly diagnosed PGL were reviewed (24 low-grade mucosa-associated lymphoid tissue [MALT], 38 aggressive non-Hodgkin's lymphoma [AGNHL]). FDG avidity, patterns (focal/diffuse), and intensity (visually vs. the liver and SUVmax) were assessed and compared to 27 controls. Gastric CT abnormalities and extragastric sites were recorded.

RESULTS

Gastric FDG uptake was found in 55/62 (89%) PGL (71% MALT vs. 100% AGNHL, p < 0.001) and 63% controls. A diffuse pattern was found in 60% PGL (76% MALT vs. 53% AGNHL, p = NS) and 47% controls. FDG uptake higher than liver was found in 82% PGL (58% MALT vs. 97% AGNHL, p < 0.05) and 63% controls. SUVmax in FDG-avid PGLs was 15.3 +/- 11.7 (5.4 +/- 2.9 MALT vs. 19.7 +/- 11.5 AGNHL, p < 0.001) and 4.6 +/- 1.4 in controls. CT abnormalities were found in 79% PGL (thickening, n = 49; ulcerations, n = 22). Extra-gastric FDG-avid sites were seen in none of MALT, but 61% of AGNHL (nodal, n = 18; nodal and extranodal, n = 5).

CONCLUSIONS

FDG avidity was present in 89% of PGLs, including all patients with AGNHL but only 71% of MALT. FDG uptake can be differentiated, in particular in AGNHL-PGL, from physiologic tracer activity by intensity but not by pattern. Extragastric foci on PET and structural CT abnormalities are additional parameters that can improve PET/CT assessment of PGL. Defining FDG avidity and PET/CT patterns in AGNHL and a subgroup of MALT-PGL before treatment may be important for further monitoring therapy response.

An important role for B-cell activation factor and B cells in the pathogenesis of Sjögren's syndrome

PURPOSE OF REVIEW

This review provides an update on the specific, strong association between dysregulated production of the cytokine B-cell activation factor and Sjögren's syndrome, and offers new perspectives on potential pathogenic mechanisms.

RECENT FINDINGS

Excess B-cell activation factor in mice triggers Sjögren's syndrome-like symptoms, and elevated serum B-cell activation factor in humans correlates with Sjögren's syndrome. B-cell activation factor is produced locally by activated monocytes, T cells and dendritic cells, and by epithelial cells and infiltrating B cells. Moreover, recent data in humans suggest that the innate immune system plays a role as an initiator of immune disorders in inflamed tissues.

SUMMARY

Recent data have demonstrated the critical role of B-cell activation factor and B cells in the pathogenesis of Sjögren's syndrome, and its association with B lymphomas. Moreover, B-cell depleting treatments have confirmed the critical role of B cells in Sjögren's syndrome. Excess B-cell activation factor possibly corrupts B-cell tolerance and allows the emergence of self-reactive B cells that efficiently present antigen to T cells. In addition, B-cell activation factor may stimulate T-cell independent activation of B cells via Toll-like receptors; this recently identified mechanism could also play a separate, detrimental role in autoimmunity.

Fluorine-18 Fluorodeoxyglucose PET/CT Patterns of Extranodal Involvement in Patients with Non-Hodgkin Lymphoma and Hodgkin's Disease

Lymphoma may originate in extranodal sites. Extranodal lymphoma may also be secondary to and accompany nodal disease. Fluorine-18 fluorodeoxyglucose (18F-FDG) imaging has an essential role in the staging of lymphoma, in monitoring the response to therapy, and in detection of recurrence. The introduction of 18F-FDG PET/CT hybrid imaging allows for accurate localization of disease and may be specifically beneficial for the detection of unexpected extranodal sites of disease or exclusion of disease in the presence of nonspecific extranodal CT findings. Accurate staging and localization often dictate the appropriate treatment strategy in patients with lymphoma. Therefore, at any stage in the course of the disease, the potential presence of extranodal disease should be considered when interpreting 18F-FDG PET/CT studies in patients with non-Hodgkin lymphoma and Hodgkin's disease.

Splenic Marginal-zone Lymphoma: One or More Entities? A Histologic, Immunohistochemical, and Molecular Study of 42 Cases

We analyzed 42 splenic marginal-zone lymphoma (SMZL) cases diagnosed on splenectomy specimens after established World Health Organization criteria. A predominantly nodular growth pattern was observed in 24 cases; the remainder showed predominantly (11/42) or exclusively (7/42) diffuse infiltration. Twenty-one cases showed the "classic" biphasic appearance; 13 cases exhibited marginal-zone morphology; finally, 8 cases were composed predominantly of small cells. CD21 and CD35 were expressed by 12/42 and 17/38 cases, respectively. DBA.44 was detected in 24/42 cases. Seventeen of 37 cases were surface IgD (SIgD)-positive. Twenty-one of 22 analyzed cases were SIgM-positive (12/21 coexpressed SIgD). Five of 37 cases were SIgG-positive. CD27 staining was observed in 21/35 cases; 7/18 CD27-positive cases coexpressed SIgD; 7/14 CD27-negative cases were SIgD-positive. Forty IGHV-D-J rearrangements were amplified in 34/42 cases: the IGHV4-34 gene predominated, followed by IGHV1-2. Using the 98% homology cut-off, 25/40 (62.5%) IGHV sequences were considered as "mutated": 10/11 cases with monomorphous, marginal-zone morphology were IGHV-mutated; in contrast, 4/6 cases with monomorphous, small-cell morphology were IGHV-unmutated. Five of 7 cases expressing IGHV1 subgroup genes had biphasic morphology, whereas 6/9 IGHV3-expressing cases had monomorphous, marginal-zone morphology. Most IGHV-mutated cases (14/20; 70%) were SIgD-negative; in contrast, 8/11 IGHV-unmutated cases expressed SIgD. CD27 was detected in 10/17 IGHV-mutated and 6/10 IGHV-unmutated cases. Seven of 11 CD27-negative cases were IGHV-mutated; 5/7 CD27-negative/IGHV-mutated cases expressed DBA.44. These results confirm the considerable histologic, immunohistochemical, and molecular heterogeneity of SMZL and indicate an origin from the diverse resident B-cell populations of the normal SMZ.

Extranodal marginal zone B-cell lymphoma of the lung in Sjögren's syndrome patients: Reappraisal of clinical, radiological, and pathology findings

BACKGROUND

Primary Sjögren's syndrome (pSs) is an autoimmune rheumatic disease that may express in a small number of patients a spectrum of lymphoproliferative diseases. The aim of this study was to describe clinical, imaging and pathology features of the extranodal marginal zone B-cell lymphoma (MZCL) of the lung of mucosa-associated lymphoid tissue (MALT) type in patients with pSs.

METHODS

All patients (N=10) with biopsy proven MZCL of the lung of MALT type diagnosed in a tertiary teaching hospital during the last 7 years were studied.

RESULTS

Seven patients had pSs. Almost all patients presented an indolent clinical course, contrasting strongly with the spectacular radiological findings in both chest roentgenograms and computed tomography. Pathology infiltration patterns observed were either nodular, peribronchial-perivascular, alveolar, or interstitial. Immunohistochemical study in all cases showed B cell phenotypes. Immunoglobulin light chain restriction was demonstrated in all patients. Monoclonal IgM(kappa) was evident in 5/7, IgM(lambda) in 1/7 and IgG (kappa) in 1/7 of patients.

CONCLUSIONS

Lung MZCL associated with pSs are characterized by an important dissociation between clinical expression and radiological pattern. Clinical presentation and imaging features are not specific. Therefore, histologic documentation is mandatory to ensure diagnosis. Various chemotherapeutic agents in combination with rituximab lead to partial or complete remission in the majority of patients.

Pathology of primary central nervous system lymphoma

✓ The understanding of primary central nervous system lymphoma (PCNSL) has lagged behind that of the much more common systemic, nodal lymphomas. Reasons for this include the relative rarity of PCNSL and the fact that these lesions differ in some ways from their histologically similar systemic counterparts. The purpose of this paper is twofold: first, the author provides concise descriptions of the pathological features of both common and uncommon types of PCNSL while discussing issues such as the confusion surrounding histological classification of PCNSLs, problems related to intraoperative diagnosis, and the appropriate diagnostic work up. Second, the author discusses a small number of molecular studies to demonstrate the great promise they offer. Such studies have already clarified some issues, including the category of lymphocyte from which the majority of PCNSLs are derived. Hopefully in the future these studies will help guide treatment decisions.

Molecular pathogenesis of MALT lymphoma: two signaling pathways underlying the antiapoptotic effect of API2-MALT1 fusion protein

At least three recurrent chromosomal translocations, t(11;18)(q21;q21), t(1;14)(p22;q32), t(14;18)(q32;q21), involving the API2-MALT1 fusion protein, BCL10 and MALT1, have been implicated in the pathogenesis of mucosa-associated lymphoid tissue (MALT) lymphoma. Several lines of evidence indicated that both BCL10 and MALT1 are required for nuclear factor kappa B (NF-kappaB) activation by antigen receptor stimulation in lymphocytes, and API2-MALT1 can bypass this BCL10/MALT1 signaling pathway. Nuclear factor kappa B activation may contribute to antiapoptotic effect through NF-kappaB-mediated upregulation of apoptotic inhibitor genes. We recently demonstrated that API2-MALT1 can induce transactivation of the API2 gene through NF-kappaB activation, thus highlighting a positive feedback-loop mechanism of self-activation by upregulating its own expression in t(11;18) MALT lymphomas. We also demonstrated that API2-MALT1 possesses an antiapoptotic effect, in part, through its direct interaction with apoptotic regulators. These findings therefore led us to hypothesize that the antiapoptotic effect by API2-MALT1 may be mediated by its interaction with apoptotic regulators, on the one hand, and by NF-kappaB-mediated upregulation of apoptotic inhibitor genes on the other. We also found that BCL10 and MALT1 are shuttling between nucleus and cytoplasm, and that MALT1 can regulate the subcellular location of BCL10.

Surgery and chemotherapy versus chemotherapy as treatment of high-grade MALT gastric lymphoma

BACKGROUND AND OBJECTIVES

Treatment of high-grade MALT (mucosa-associated lymphoid tissue) gastric lymphoma remains uncertain. To assess efficacy and toxicity of the most common therapies--surgery followed by chemotherapy or chemotherapy alone--we began a controlled clinical trial in patients in early stage (I and II 1).

METHODS

One hundred and two patients were randomized to be treated with surgery followed by six cycles of CEOP-Bleo (cyclophosphamide, epirubicin, vincristine, prednisone, and bleomycin at standard doses) (52 cases) or with chemotherapy alone (49 cases).

RESULTS

Complete response rates were 94% [95% confidence interval (CI): 88-99%] and 96% (93-100%), respectively. Actuarial curves at 5 yr showed that event-free survival were 70% (95% CI: 59-74%) in patients treated with surgery and chemotherapy, that were not statistically significant to 67% (95% CI: 51-69%) in the patients who received chemotherapy (p = 0.5). Also, overall survival that was not statistically significant: 78% (95% CI: 70-88%) in the combined treatment and 76% (95% CI: 70-87%) in chemotherapy (p = 0.8). Acute and late toxicity were mild and well controlled. No acute leukemia or second neoplasm has been observed.

CONCLUSIONS

The use of surgery and chemotherapy did not improve outcome in patients with early-stage high-grade gastric MALT lymphoma. It is apparent that chemotherapy alone is sufficient treatment in this select group of patients.

Surgery and chemotherapy versus chemotherapy as treatment of high-grade MALT gastric lymphoma

BACKGROUND AND OBJECTIVES

Treatment of high-grade MALT (mucosa-associated lymphoid tissue) gastric lymphoma remains uncertain. To assess efficacy and toxicity of the most common therapies--surgery followed by chemotherapy or chemotherapy alone--we began a controlled clinical trial in patients in early stage (I and II 1).

METHODS

One hundred and two patients were randomized to be treated with surgery followed by six cycles of CEOP-Bleo (cyclophosphamide, epirubicin, vincristine, prednisone, and bleomycin at standard doses) (52 cases) or with chemotherapy alone (49 cases).

RESULTS

Complete response rates were 94% [95% confidence interval (CI): 88-99%] and 96% (93-100%), respectively. Actuarial curves at 5 yr showed that event-free survival were 70% (95% CI: 59-74%) in patients treated with surgery and chemotherapy, that were not statistically significant to 67% (95% CI: 51-69%) in the patients who received chemotherapy (p = 0.5). Also, overall survival that was not statistically significant: 78% (95% CI: 70-88%) in the combined treatment and 76% (95% CI: 70-87%) in chemotherapy (p = 0.8). Acute and late toxicity were mild and well controlled. No acute leukemia or second neoplasm has been observed.

CONCLUSIONS

The use of surgery and chemotherapy did not improve outcome in patients with early-stage high-grade gastric MALT lymphoma. It is apparent that chemotherapy alone is sufficient treatment in this select group of patients.

BCL2 gene abnormalities define distinct clinical subsets of follicular lymphoma

AIMS

Follicular lymphoma (FL) arising primarily in the skin has recently been proposed as a distinct entity on the basis of a low incidence of t(14;18)(q32;q21) and bcl-2 expression, with a very high percentage of patients surviving more than 5 years. However, cases of t(14;18)(q32;q21)-positive primary cutaneous FL (PCFL) and examples of t(14;18)(q32;q21)-negative FL at nodal and other extranodal sites, are well documented. The aim of this study was to test the hypothesis that there is a subtype of FL lacking t(14;18)(q32;q21), which preferentially involves certain sites but is not restricted by anatomical location.

METHODS AND RESULTS

A cohort of 47 stage 1 FL was stratified according to the presence or absence of t(14;18)(q32;q21) using conventional cytogenetics, polymerase chain reaction and interphase fluorescence in situ hybridization. Compared with t(14;18)(q32;q21)-positive cases, FL lacking the translocation were less likely to express CD10 or bcl-2 (P<0.01), made up a significantly greater proportion of cases arising at extranodal sites (P<0.001) and had a significantly better overall and disease-specific 5-year survival (P<0.01).

CONCLUSIONS

These results support the concept of a subtype of FL lacking t(14;18)(q32;q21), characterized by low-intensity bcl-2 expression, a predilection for extranodal sites, particularly the skin, and a more favourable outcome than t(14;18)(q32;q21)-positive FL.

Aberrant nuclear BCL10 expression and lack of t(11;18)(q21;q21) in primary cutaneous marginal zone B-cell lymphoma

Inhibition of apoptosis seems to play an important role in the pathogenesis of marginal zone lymphoma. Apoptosis regulator B-cell lymphoma 10 (BCL10) may show aberrant nuclear localization in some aggressive extracutaneous MALT lymphomas, often in association with a MALT1 gene t(11;18)(q21;q21) translocation. The possible occurrence of this association in primary cutaneous marginal zone lymphoma (PCMZL) remains insufficiently explored. The aim of this study was to evaluate BCL10 protein expression pattern and its possible relationship to the presence of t(11;18)(q21;q21) and other MALT1 gene abnormalities in PCMZL and to assess their clinical significance. The study included 42 consecutive PCMZL patients diagnosed on the basis of the World Health Organization/European Organization for the Research and Treatment of Cancer classification criteria. BCL10 expression was immunohistochemically evaluated in all cases, whereas t(11;18)(q21;q21) reverse transcriptase polymerase chain reaction amplification was performed on 21 samples. In addition, the presence of other MALT1 gene translocations was explored in 26 samples by interphase fluorescence in situ hybridization using a MALT1 locus-specific probe. We observed the presence of aberrant nuclear BCL10 expression in a significant number of PCMZL cases (36%, 15/42). This aberrant expression was significantly related to the development of extracutaneous disease. In contrast, neither the t(11;18)(q21;q21) translocation nor other MALT1 gene translocations could be demonstrated. t(11;18)(q21;q21), strongly linked to extracutaneous MALT lymphomas, does not seem to play a role in PCMZL. The participation of other MALT1 gene translocations in PCMZL pathogenesis seems also unlikely.

Management of marginal zone lymphomas

Marginal-zone lymphoma (MZL) includes three subtypes depending on the site of lymphoma involvement: extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma); splenic MZL; and nodal MZL. Although there is a common cell of origin and similarities concerning a possible chronic antigenic stimulation by microbial pathogens and/or auto-antigens, the clinical presentation is very different with symptoms related to lymphoma location. MALT and splenic MZL present with an indolent disease with good performance status, no B symptoms, and no adverse prognostic factors and are associated with long survival. Patients with nodal MZL present with a shorter progression-free survival. Clinical and biological prognostic factors identified in reported series are heterogeneous. The optimal treatment has yet to be defined for the three subtypes, and current strategies are described in this review.

Extranodal marginal zone B-cell lymphoma mimicking meningioma in lateral ventricle : a case report and possible pathogenesis

We report a case of extranodal marginal zone B-cell lymphoma (MZL) mimicking meningioma in a lateral ventricle and suggest its possible pathogenesis. The patient was a 63-year-old male with seizure attack. MRI showed a 3.5x1.7 cm sized homogeneously enhancing mass in the trigon of the right lateral ventricle, possibly arising from the choroid plexus. The provisional diagnosis was meningioma or metastasis. In the surgical findings, the mass was attached to the choroid plexus and totally removed. Pathologic examination revealed a monotonous population of medium-sized mononuclear lymphoma cells associated with meningothelial whorl formation and neoplastic cells which invaded the meningothelial cells. The tumor was immunopositive for CD79a, CD20, CD43 and bcl-2. We suggest that intracranial extranodal marginal zone B-cell lymphomas might mimic meningiomas, because of their relation with the arachnoid cells and that meningothelial cells serve as a substitute for the mucosal surface in intracranial MALT lymphomas.

NCI Thesaurus: a semantic model integrating cancer-related clinical and molecular information

Over the last 8 years, the National Cancer Institute (NCI) has launched a major effort to integrate molecular and clinical cancer-related information within a unified biomedical informatics framework, with controlled terminology as its foundational layer. The NCI Thesaurus is the reference terminology underpinning these efforts. It is designed to meet the growing need for accurate, comprehensive, and shared terminology, covering topics including: cancers, findings, drugs, therapies, anatomy, genes, pathways, cellular and subcellular processes, proteins, and experimental organisms. The NCI Thesaurus provides a partial model of how these things relate to each other, responding to actual user needs and implemented in a deductive logic framework that can help maintain the integrity and extend the informational power of what is provided. This paper presents the semantic model for cancer diseases and its uses in integrating clinical and molecular knowledge, more briefly examines the models and uses for drug, biochemical pathway, and mouse terminology, and discusses limits of the current approach and directions for future work.

Contribution of Immunohistochemistry to Small B-Cell Lymphoma Classification

Although the small B-cell lymphomas show major morphologic overlapping, they have been recently shown to be distinct entities with several biologic and clinical differences. Therefore, the utility of a panel of paraffin-reactive antibodies in differentiating these neoplasms was investigated. Using clinical data and morphologic criteria, 134 cases of small B-cell lymphomas were grouped as those with (1) one strongly suggested diagnosis, (2) differential diagnosis between two types of lymphomas, and (3) small B-cell lymphoma without hints for further subclassification. With a panel of antibodies including CD5, CD10, CD23, CD43, bcl-2, and cyclin D1, most but not all cases could be precisely categorized. This panel confirmed the diagnosis in 96.5% of the cases from group 1. In group 2 it confirmed one of the two diagnoses in 81.5% of the cases. In group 3 it established a definitive diagnosis in 55% of the cases. When all groups were considered, a correct diagnosis could be established for 88.1% of cases; for 6.7% of them the authors remained with two possible diagnosis, and the broad "small B-cell lymphoma" was the only diagnosis for 5.2% of cases. CD10 separated most follicular lymphomas from other small B-cell lymphoid neoplasms. CD23 separated small lymphocytic lymphoma/chronic lymphocytic leukemia. Cyclin D1 separated mantle cell lymphoma. The present study selected CD10, CD23, and cyclin D1 as a minimal panel for the classification of small B-cell lymphomas, yielding a final diagnosis in 88.1% of the cases.

Marginal zone lymphoma with a dual cutaneous and leukemic presentation and an aberrant myeloid-monocytic phenotype

Marginal zone lymphoma (MZL) is an indolent neoplasm of mature B cells, classified by the World Health Organization into three categories: nodal, splenic, and extranodal MZL of mucosa-associated lymphoid tissue (MALT lymphoma). We present an unusual case of MZL with cutaneous, leukemic, and bone marrow involvement at presentation and expression of an aberrant myeloid-monocytic phenotype. This case is best classified as MZL of leukemic subtype.

Mucosa-associated lymphoid tissue (MALT) lymphoma of the stomach: results of a controlled clinical trial

Treatment of patients with early stage gastric mucosa-associated lymphoid tissue (MALT) remains undefined. We began a controlled clinical trial to evaluate efficacy and toxicity of the most common therapies. Two hundred and forty-one patients with gastric low-grade MALT lymphoma in early stage (IE and IIE) were randomized to surgery (80 cases), radiotherapy (78 cases), and chemotherapy (83 cases). With a median follow-up of 7.5 yr, actuarial curves at 10 yr showed that event-free survival was 52% in patients treated with surgery, 52% in radiotherapy arm, and 87% in the chemotherapy group (p < 0.01). However, overall survival did not showed any statistical differences: 80%, 75% and 87%, respectively (p = 0.4). Acute and late toxicities were mild. No death-related treatments were observed. No clear differences were observed between the most common therapies in patients with primary gastric MALT lymphoma in early stages, probably because this type of lymphoma has an high response rate to salvage treatment after failure to local treatment (surgery and radiotherapy). Thus considered, chemotherapy alone is an effective and safe therapeutic approach in this setting of patients. Surgery or radiotherapy will be reserved to patients that are not candidates for chemotherapy.

Mucosa-associated lymphoid tissue (MALT) lymphoma of the stomach: results of a controlled clinical trial

Treatment of patients with early stage gastric mucosa-associated lymphoid tissue (MALT) remains undefined. We began a controlled clinical trial to evaluate efficacy and toxicity of the most common therapies. Two hundred and forty-one patients with gastric low-grade MALT lymphoma in early stage (IE and IIE) were randomized to surgery (80 cases), radiotherapy (78 cases), and chemotherapy (83 cases). With a median follow-up of 7.5 yr, actuarial curves at 10 yr showed that event-free survival was 52% in patients treated with surgery, 52% in radiotherapy arm, and 87% in the chemotherapy group (p < 0.01). However, overall survival did not showed any statistical differences: 80%, 75% and 87%, respectively (p = 0.4). Acute and late toxicities were mild. No death-related treatments were observed. No clear differences were observed between the most common therapies in patients with primary gastric MALT lymphoma in early stages, probably because this type of lymphoma has an high response rate to salvage treatment after failure to local treatment (surgery and radiotherapy). Thus considered, chemotherapy alone is an effective and safe therapeutic approach in this setting of patients. Surgery or radiotherapy will be reserved to patients that are not candidates for chemotherapy.

Mucosa-associated lymphoid tissue (MALT) lymphoma of the stomach: results of a controlled clinical trial

Treatment of patients with early stage gastric mucosa-associated lymphoid tissue (MALT) remains undefined. We began a controlled clinical trial to evaluate efficacy and toxicity of the most common therapies. Two hundred and forty-one patients with gastric low-grade MALT lymphoma in early stage (IE and IIE) were randomized to surgery (80 cases), radiotherapy (78 cases), and chemotherapy (83 cases). With a median follow-up of 7.5 yr, actuarial curves at 10 yr showed that event-free survival was 52% in patients treated with surgery, 52% in radiotherapy arm, and 87% in the chemotherapy group (p < 0.01). However, overall survival did not showed any statistical differences: 80%, 75% and 87%, respectively (p = 0.4). Acute and late toxicities were mild. No death-related treatments were observed. No clear differences were observed between the most common therapies in patients with primary gastric MALT lymphoma in early stages, probably because this type of lymphoma has an high response rate to salvage treatment after failure to local treatment (surgery and radiotherapy). Thus considered, chemotherapy alone is an effective and safe therapeutic approach in this setting of patients. Surgery or radiotherapy will be reserved to patients that are not candidates for chemotherapy.

Clinicopathologic and genetic profile of intracranial marginal zone lymphoma: a primary low-grade CNS lymphoma that mimics meningioma

PURPOSE

Although rare overall, marginal zone B-cell lymphoma (MZBCL) is the most common primary low-grade CNS lymphoma reported in the literature. The aim of this study is to elucidate the biology and genetic features of this unusual tumor.

PATIENTS AND METHODS

Fifteen CNS MZBCLs were studied clinically, pathologically, and genetically, including fluorescent in situ hybridization analyses with commercially available MALT1 and IgH break-apart and centromere 3, 7, 12, and 18 probes.

RESULTS

CNS MZBCLs preferentially affect middle-aged women (female-to-male ratio, 4:1), with 93% presenting as dural-based masses mimicking meningioma. Ten patients with 1 to 7.6 years of follow-up after diagnosis showed no evidence of disease after radiation and/or chemotherapy. Like MZBCLs outside of the CNS, they consisted of CD20+, CD3- small B lymphocytes with varying degrees of plasmacytic differentiation and predominantly kappa light-chain restriction (78%). Lymphoid follicles with follicular colonization were seen in three patients and deposition of amyloid was noted in samples from two patients, one of which was tumefactive. Neither Bcl-6 protein nor Epstein-Barr virus-encoded RNA was expressed. Trisomy 3 was detected in six of 12 patients, with no rearrangements of MALT1 or IgH and no trisomies of 7, 12, or 18 detected.

CONCLUSION

Our data suggest that intracranial MZBCL is an indolent primary CNS lymphoma that typically presents as a meningioma-like dural-based mass. Trisomy 3, but not MALT1 or IgH translocation, is a common genetic abnormality that may contribute to the pathogenesis of this CNS lymphoma.

Expression of BAFF-R (BR 3) in normal and neoplastic lymphoid tissues characterized with a newly developed monoclonal antibody

BAFF-receptor (BAFF-R) is required for the successful maturation and survival of B-cells. We developed an anti-human BAFF-R monoclonal antibody (mAb), 8 A 7. The reactivity of 8 A 7 in normal and neoplastic tissue was examined by performing immunohistochemistry on paraffin-embedded sections. 8 A 7 reacted with lymphocytes in the mantle and marginal zones, but not with lymphocytes in the interfollicular area. Lymphocytes in the germinal centers were found to be negative or occasionally weakly positive for 8 A 7. BAFF-R expression was found only in B-cell lymphoma (44/80, positive cases/examined cases): B-lymphoblastic lymphoma 0/3, B-chronic lymphocytic leukemia/small lymphocytic lymphoma 4/4, mantle cell lymphoma 9/11, follicular lymphoma 10/14, diffuse large B-cell lymphoma (DLBCL) 11/25, marginal zone B-cell lymphoma 8/10, lymphoplasmacytic lymphoma 2/2, plasma cell myeloma 0/2, and Burkitt lymphoma 0/9, but not in T/NK cell lymphomas (0/19) or Hodgkin lymphoma (0/10). BAFF-R was expressed in most low-grade B-cell neoplasms and a small number of DLBCL, suggesting that BAFF-R may play an important role in the proliferation of neoplastic lymphoid cells. Thus, the mAb is very useful for further understanding of both healthy B-cell biology and its pathogenic neoplasms.

Constitutive expression of the AP-1 transcription factors c-jun, junD, junB, and c-fos and the marginal zone B-cell transcription factor Notch2 in splenic marginal zone lymphoma

Splenic marginal zone lymphoma (SMZL) is a lymphoma type of putative marginal zone B-cell origin. No specific genetic alterations have yet been demonstrated in SMZL. Clinically, SMZL is a low-grade B-cell non-Hodgkin lymphoma. However, the presence of p53 mutation, 7q22-7q32 deletion or the absence of somatic hypermutations of immunoglobulin genes has been correlated with a worse prognosis. In this study, we analyzed genome-wide gene expression of 24 cases of SMZL using the microarray technique. The AP-1 transcription factors c-jun, junD, junB, and c-fos as well as Notch2 were found to be specifically up-regulated. These data were confirmed by real-time PCR and immunohistochemical staining of tissue sections. The absence of concordant high expression of the MAP kinases, the signaling cascade leading to AP-1 up-regulation, suggests autoregulation of the AP-1 transcription factors and an important role in SMZL oncogenesis. High expression of Notch2, a transcription factor that induces marginal zone B-cell differentiation, is highly suggestive for a marginal zone B-cell origin of SMZL. In addition, SMZL with the 7q deletion showed high expression of TGF-beta1 and low expression of the DNA helicase XPB, a crucial part of the nucleotide excision repair complex, possibly explaining the more aggressive clinical course of those cases.

Paraffin section interphase fluorescence in situ hybridization in the diagnosis and classification of non-hodgkin lymphomas

Cytogenetic data can contribute valuable information that may assist in the diagnosis and classification of non-Hodgkin lymphomas and may in some cases also provide prognostic information. Interphase fluorescence in situ hybridization (FISH) studies offer the ability to assess for characteristic cytogenetic abnormalities even when material for standard metaphase cytogenetic analysis is not available. This review discusses the use of FISH in paraffin-embedded material with particular attention paid to the use of intact thin paraffin sections. The basic principles of FISH analysis are summarized, the advantages and disadvantages of analysis of thin paraffin sections rather than intact nuclei are discussed, and the more commonly encountered artifacts are considered. Each of the well-characterized cytogenetic abnormalities that are associated with particular types of non-Hodgkin lymphoma and can be detected with commercially available FISH probes is discussed individually. In particular, their incidence in various types of lymphoma is reviewed, the types of commercially available FISH probes to detect such abnormalities are discussed, and clinical situations where such analysis can be of diagnostic utility are described.