Diffuse low-grade B-cell lymphomas. Four clinically distinct subtypes defined by a combination of morphologic and immunophenotypic features

Incidentally Discovered Extranodal Marginal Zone B-Cell Lymphoma of Mucosa-Associated Lymphoid Tissue in the Colon

We present a case of colonic mucosa-associated lymphoid tissue (MALT) lymphoma in a 62-year-old woman diagnosed after a positive test for fecal occult blood.

Potential effects of CRM1 inhibition in mantle cell lymphoma

Mantle cell lymphoma (MCL) is an aggressive histotype of B-cell non-Hodgkin lymphoma. The disease has no known cure, which prompts the urgent need for novel therapeutic agents. Chromosomal region maintenance 1 (CRM1) may play a role in human neoplasia and serve as a novel target of cancer treatment. This study summarizes MCL pathogenesis and determines the involvement of CRM1 in the regulation of several vital signaling pathways contributing to MCL pathogenesis, including the pathways of cell cycle progression, DNA damage response, phosphoinositide kinase-3, nuclear factor-κB activation, and chromosomal stability. A preclinical study is also presented to compare the CRM1 status in MCL cell lines and primary MCL cells with normal B cells, as well as the therapeutic efficiency of CRM1 inhibition in MCL in vitro and in vivo, which make these agents potential targets of novel MCL treatments.

Clinical study of mucosa-associated lymphoid tissue lymphomas of the head and neck

BACKGROUND

Limited information is available on mucosa-associated lymphoid tissue lymphomas arising in the head and neck.

METHOD

A retrospective analysis was conducted of 20 patients who were histologically diagnosed with mucosa-associated lymphoid tissue lymphoma and treated at our institution between January 1990 and December 2009.

RESULTS

Treatment consisted of surgical resection alone in two patients (10 per cent), surgical resection with consecutive radiotherapy in one (5 per cent), and radiotherapy alone in eight (40 per cent). Three patients (15 per cent) were treated with systemic chemotherapy, and three (15 per cent) received chemoradiotherapy. Three patients (15 per cent) were informed of the diagnosis but not treated for their condition.

CONCLUSION

All of the 20 patients were still alive after a mean follow-up period of 50.8 months. Local treatment for mucosa-associated lymphoid tissue lymphoma of the head and neck should be the first choice in early-stage disease. However, prolonged follow up is important to determine these patients' long-term response to treatment.

Mantle cell lymphoma

MCL is a well-characterized clinically aggressive lymphoma with a poor prognosis. Recent research findings have slightly improved the outcome of this neoplasm. The addition of rituximab to conventional chemotherapy has increased overall response rates, but it does not improve overall survival with respect to chemotherapy alone. The use of intensive frontline therapies including rituximab and consolidated by ASCT ameliorates response rate and prolongs progression-free survival, but any impact on survival remains to be proven. Furthermore, the optimal timing, cytoreductive regimen and conditioning regimen, and the clinical implications of achieving a disease remission even at molecular level remain to be elucidated. The development of targeted therapies as the consequence of better dissection of pathogenetic pathways in MCL might improve the outcome of conventional chemotherapy in most patients and spare the toxicity of intense therapy in a minority of MCL patients characterized by a relatively indolent disease. Patients not eligible for intensive regimens, such as hyperC-VAD, may be considered for less demanding therapies, such as the combination of rituximab either with CHOP or with purine analogues, or bendamustine. Allogeneic SCT can be an effective option for relapsed disease in patients who are fit enough and have a compatible donor. Maintenance rituximab may be considered after response to immunochemotherapy for relapsed disease, although there are currently no data to recommend this approach as the first-line strategy. As the optimal approach to the management of MCL is still evolving, it is critical that these patients be enrolled in clinical trials to identify better treatment options.

A distinctive subtype of t(14;18)-negative nodal follicular non-Hodgkin lymphoma characterized by a predominantly diffuse growth pattern and deletions in the chromosomal region 1p36

Follicular lymphoma (FL) is a morphologically and genetically well-characterized B-cell non-Hodgkin lymphoma that can show predominantly follicular, combined follicular and diffuse, or predominantly diffuse growth patterns. Although approximately 85% of FLs harbor the translocation t(14;18)(q32;q21) and consistently display a follicular growth pattern, predominantly diffuse FLs are less well characterized on the phenotypical, molecular, and clinical level. We studied 35 predominantly diffuse FL by immunohistochemistry, classical chromosome banding analysis, fluorescence in situ hybridization (FISH), and gene expression profiling. A total of 28 of 29 analyzable cases lacked t(14;18), and 27 of 29 cases revealed a unifying chromosomal aberration, a deletion in 1p36. Morphologically, 12 FLs were grade 1 and 23 were grade 2, and the immunophenotype with frequent expression of CD10, BCL6, and CD23 was in line with a germinal center B-cell phenotype. The gene expression profiles of 4 predominantly diffuse FLs fell into the spectrum of typical FL, with a unique enrichment of specific gene signatures. Remarkably, patients with diffuse FL frequently presented with low clinical stage and large but localized inguinal tumors. These results suggest that predominantly diffuse FL represent a distinct subtype of t(14;18)-negative nodal FL with a unifying genetic alteration (deletion of 1p36) and characteristic clinical features.

Recurrence of primary breast lymphoma in contralateral breast: case report and review of the literature

Lymphoma presenting as a breast mass is rare, although well documented. Although recurrence rates can reach approximately 50%, recurrence in the contralateral breast is rare. We report a case of recurrent primary breast lymphoma (PBL), which was discovered on screening mammography after a 5-year disease-free interval from initial diagnosis.

The critical role of histology in an era of genomics and proteomics: a commentary and reflection

The role of histologic examination in lymphoma diagnosis has been called into question by proponents of new technologies, such as genomics and proteomics. We review the history and salient features of morphologic evaluation in lymphoid diseases, and discuss the general and specific limitations of mature ancillary techniques, such as immunohistochemistry, flow cytometry, and molecular studies. We then speculate on the future relationship between morphology and the new genomic and proteomic technologies as they become integrated into clinical practice.

"In situ-like" mantle cell lymphoma: a report of two cases

Mantle cell lymphoma (MCL) is a B cell neoplasm that most often shows a diffuse growth pattern. Two cases of MCL are reported here, both with a previous diagnosis of lymphoid hyperplasia. Morphologically, germinal centres are hyperplasic with a normal or discretely enlarged mantle zone, where foci of irregularly shaped small lymphocytes are seen. These are positive for CD20, CD5 and cyclin D1, confirming a diagnosis of in situ-like MCL. This type differs from the mantle zone pattern in that the neoplastic mantle zone is very thin and there is very little or no spread of tumour cells into interfollicular areas. To the best of our knowledge, this is the first report on such a pattern of MCL, which is important to recognise, as it can be confused with lymphoid hyperplasia.

CD5-Positive B-Cell Neoplasms of Indeterminate Immunophenotype

The flow cytometric classification of CD5-positive small B-cell neoplasms is dependent largely on the differential expression of CD23 and FMC-7. Occasional CD5-positive neoplasms with prominent co-expression of these antigens are encountered, precluding definitive immunophenotypic classification. The authors studied the clinicopathologic features of 26 neoplasms with this indeterminate immunophenotype. Available morphologic material was reviewed and analysis of CYCLIN D1 derangement was performed in selected cases by a combination of immunohistochemical, molecular, and cytogenetic techniques. Individual neoplasms were classified based on correlation of morphologic features and results of CYCLIN D1 studies. The neoplasms were classified into five categories: chronic lymphocytic leukemia (14 cases), "favor chronic lymphocytic leukemia" (3 cases), mantle cell lymphoma (3 cases), lymphoplasmacytic lymphoma (1 case), and unclassifiable (5 cases). Three of the unclassifiable neoplasms had morphologic features of mantle cell lymphoma, but CYCLIN D1 derangement could not be demonstrated. Neither relative expression of CD23 and FMC-7 nor intensity of CD20 or surface immunoglobulin expression was helpful in final classification. The authors conclude that CD5-positive small B-cell neoplasms with an indeterminate immunophenotype are a heterogeneous group, requiring additional studies for final classification. The majority (65%) appear to be chronic lymphocytic leukemia, with most of the remaining cases either definitively mantle cell lymphoma or unclassifiable.

Evaluation of peripheral blood involvement of mantle cell lymphoma by fluorescence in situ hybridization in comparison with immunophenotypic and morphologic findings

Mantle cell lymphoma is non-Hodgkin's B-cell lymphoma characterized by the t(11;14)(q13;q32) translocation. Peripheral blood involvement of mantle cell lymphoma is usually associated with a poor prognosis and therefore, its identification is clinically important. In this study, we performed cyclin D1/IgH-probe fusion fluorescence in situ hybridization analysis on 223 peripheral blood samples: 185 from 125 mantle cell lymphoma patients, and 38 normal controls. The cutoff values for the test were established using normal controls. Flow cytometry on peripheral blood and corresponding bone marrow samples was used to evaluate this test. In all, 26% of the 185 peripheral blood samples and 27% of the 161 corresponding bone marrow samples were flow cytometry positive for mantle cell lymphoma. The mean numbers of single and- double-fusion signals and the mean number of CD5/CD19-positive cells, absolute blood lymphocyte count, and white blood cell count were significantly higher in peripheral blood and corresponding bone marrow samples with mantle cell lymphoma-positive flow cytometry. Double-fusion signals were more specific than single-fusion ones. Fluorescence in situ hybridization was far more likely to be positive for mantle cell lymphoma when the peripheral blood and the corresponding bone marrow samples had positive flow cytometry results or morphology (P<0.01). Our study indicates that cyclin D1/IgH-fusion fluorescence in situ hybridization analysis could be used to determine the presence and character of circulating mantle cell lymphoma cells in peripheral blood, thus enhancing our ability to evaluate leukemic mantle cell lymphoma and minimum residual disease.

Lymphomas

Hodgkin's and non-Hodgkin's lymphomas are an important part of the differential diagnosis of head and neck tumors. Their diagnosis begins with a complete history and physical examination and is confirmed with an appropriately obtained and prepared pathologic specimen. Prognosis and therapy of the lymphomas vary depending on stage and the characteristics of each particular subtype of lymphoma. Low-grade lymphomas and chronic lymphocytic leukemia are characterized by long survival times and are most often treated with palliative intent. More aggressive high-grade lymphomas are treated for cure. Although chemotherapy and radiotherapy remain the mainstays of treatment, immunotherapy demonstrates increasing promise.

Investigatory and analytical approaches to differential gene expression profiling in mantle cell lymphoma

Mantle cell lymphoma (MCL) is a non-Hodgkin's lymphoma of B-cell lineage. The blastoid variant of MCL, characterized by high mitotic rate, is clinically more aggressive than common MCL. We used the cDNA array technology to examine the gene expression profiles of both blastoid variant and common MCL. The data was analysed by regression analysis, principal component analysis and the naive Bayes' classifier. Eight genes were identified as differentially deregulated between the two groups. Oncogenes CMYC, BCL2 and PIM1 were upregulated more frequently in the blastoid variant than in common MCL. This implied that the gp130-mediated signal transducer and activator of transcription 3 (STAT3) signalling pathway was involved in the blastoid variant transformation of MCL. Other differentially deregulated genes were TOP1, CD23, CD45, CD70 and NFATC. By using the eight differentially deregulated genes, we created a classifier to distinguish the blastoid variant from common MCL with high accuracy. We also identified 18 genes that were deregulated in both groups. Among them, BCL1, CALLA/CD10 and GRN were suggested to be oncogenes. The products of RGS1, RGS2, ANX2 and CD44H were suggested to promote tumour metastasis. CD66D was suggested to be a tumour suppressor gene.

Proteins encoded by genes involved in chromosomal alterations in lymphoma and leukemia: clinical value of their detection by immunocytochemistry

Acquired chromosomal anomalies (most commonly translocations) in lymphoma and leukemia usually result in either activation of a quiescent gene (by means of immunoglobulin or T-cell-receptor promotors) and expression of an intact protein product, or creation of a fusion gene encoding a chimeric protein. This review summarizes current immunocytochemical studies of these 2 categories of oncogenic protein, with emphasis on the clinical relevance of their detection in diagnostic samples. Among the quiescent genes activated by rearrangement, expression of cyclin D1 (due to rearrangement of the CCND1 [BCL-1] gene) is a near-specific marker of t(11;14) in mantle cell lymphoma; BCL-2 expression distinguishes follicular lymphoma cells from their nonneoplastic counterparts in reactive germinal centers and appears to be an independent prognostic marker in diffuse large cell lymphoma; and TAL-1 (SCL) expression identifies T-cell acute lymphoblastic neoplasms in which this gene is activated. The protein products of other genes activated by chromosomal rearrangement have a role as markers of either lineage (eg, PAX-5 [B-cell-specific activator protein] for B cells, including B-lymphoblastic neoplasms), or maturation stage (eg, BCL-6 for germinal-center and activated B cells and MUM-1/IRF4 for plasma cells). Currently, no hybrid protein encoded by fusion genes is reliably detectable by antibodies recognizing unique junctional epitopes (ie, epitopes absent from the wild-type constituent proteins). Nevertheless, staining for promyelocytic leukemia (PML) protein will detect acute PML with t(15;17) because the microspeckled nuclear labeling pattern for PML-RARalpha is highly distinctive. Similarly, antibodies to the anaplastic lymphoma kinase (ALK) tyrosine kinase are valuable (because wild-type ALK is not found in normal lymphoid tissue) in detecting neoplasms (CD30-positive large T-cell lymphomas) with t(2;5) or its variants. Thus, immunocytochemical detection of the products of many rearranged genes in lymphoma and leukemia can be clinically informative and provide information on cellular and subcellular protein expression that cannot be inferred from studies based on messenger RNA.

The splenic form of mantle cell lymphoma

OBJECTIVES

To describe the clinical, immunophenotypic and molecular features, as well as the clinical course of patients with unusual presentation of mantle cell lymphoma (MCL) purely located to the spleen.

PATIENTS AND METHODS

We describe seven patients presented with splenomegaly and a leukemic picture without lymphadenopathy, fulfilling the diagnostic criteria of MCL. In addition to clinical and pathologic features, patients were studied with respect to surface immunophenotype, including adhesion molecule profile, immunohistochemical expression of cyclin-D1 and bcl-1 rearrangement by polymerase chain reaction.

RESULTS

Four patients were male and three female. The median palpable spleen size was 15 cm. A preliminary diagnosis of MCL was made, based on blood cell morphology and immunophenotype. All patients underwent splenectomy for therapeutic purposes. Studies done in blood and splenic lymphocytes revealed the following: 7/7 patients were CD19/CD5, CD20 and CD38 positive; CD10 negative and 6/7 CD23 negative. The adhesion molecule expression pattern was consistent in all patients: L-Selectin and CD11c were negative, CD11alpha and CD18 weakly positive and CD54 strongly positive. The median spleen weight was 1775 g. Histology disclosed a cytologic and architectural pattern consistent with MCL. Cyclin-D1 was positive in 6/6 studied patients. Bcl-1 rearrangement was found in 5/7 patients. Splenectomy was applied as the sole treatment and was beneficial in all patients, with median blood values as following: prior to splenectomy, Ht 29.5%, platelets 110 x 10(9)/l, lymphoma cells 5.0 x 10(9)/L, and at 6 months post-splenectomy, Ht 43%, platelets 311 x 10(9)/l and lymphoma cells 3.0 x 10(9)/L. Of the seven patients, two developed progressive disease 11 and 26 months post-splenectomy. The remaining five are in improving clinical and hematological condition without chemotherapy at a median follow up of 20 months.

CONCLUSIONS

We conclude that this presentation represents a separate form of MCL which requires splenectomy. It remains to be seen whether it carries a better prognosis than classical MCL.

Cyclophosphamide/fludarabine (CF) is active in the treatment of mantle cell lymphoma

The purpose of this study was to determine the efficacy and toxicity of the cyclophosphamide and fludarabine (CF) regimen in patients with newly diagnosed and relapsed/refractory mantle cell lymphoma (MCL). Thirty patients with pathologically confirmed MCL were treated with the CF regimen. Ten (33%) had no prior therapy, six (20%) had one previous regimen, and 14 (47%) received two or more prior regimens. Ninety cycles of CF with a median of 3 cycles/patient (range, 1-5 cycles) were administered to patients with MCL. Nine patients (30%) had a complete response (CR) and 10 (33%) had a partial response (PR) for an overall response rate (RR) of 63%. The median failure-free survival (FFS) and overall survival (OS) was 4.8 months and 17.5 months, respectively. When patients were analyzed based upon the number of previous treatments (0, 1, or 2 or more), those with no previous treatment (n=10) had an overall response of 100%, with 70% CR. The median FFS was 28.1 months and the median OS for this group has not been reached at 42.3+ months. Hematologic and infectious toxicity were the major toxicities encountered with the CF regimen. Grade 3-4 neutropenia, thrombocytopenia and anemia were seen in 50%, 37%, and 36% of patients, respectively. There were 13 episodes of grade 3 infections. There was no treatment related mortality, In conclusion, the high response rate associated with the CF regimen merits further investigation in previously untreated patients with MCL, particularly in those who are not candidates for aggressive therapy.

Lymphoma immunophenotyping: a new era in paraffin-section immunohistochemistry

Recent advances in immunohistochemistry have made it possible to investigate lymphomas for the expression of a wide range of antigens in fixed tissues. Epitope retrieval, sensitive detection methods, and the availability of new monoclonal antibodies have all contributed to one's ability to perform detailed immunophenotyping that previously could only be done in cryostat sections or by flow cytometry. Current lymphoma classifications make use of characteristic immunophenotypic profiles that aid in the reproducible diagnosis and subcassification of these neoplasms. The following is a review of the current state of immunophenotyping for lymphoid neoplasms in fixed tissues.

Is lymphoplasmacytic lymphoma/immunocytoma a distinct entity? A clinicopathologic study of 20 cases

Lymphoplasmacytic lymphoma/immunocytoma (LLI) was defined initially as a small B-cell lymphoma with plasmacytoid or plasmacytic features. Because other types of small B-cell lymphoma, particularly marginal zone B-cell lymphoma may exhibit plasmacytic differentiation, the revised European-American lymphoma classification and World Health Organization has defined LLI more narrowly to exclude other small B-cell lymphomas. The goal of this study was to reevaluate LLI as a clinicopathologic entity. Twenty cases were selected from 43 previously diagnosed as "small lymphocytic lymphoma, plasmacytoid" or "immunocytoma" from 1985 to 1998. Cases fulfilling the criteria for B-cell small lymphocytic lymphoma, follicular lymphoma, marginal zone B-cell lymphoma, or other types of B-cell lymphoma were excluded. The histopathology and immunoreactivity for CD20, CD79a, CD3, CD43, CD23, CD5, kappa, lambda, and immunoglobulins (Ig's) M, G, and A were reviewed, in addition to available clinical findings. There were 13 men and seven women, with a mean age of 69 years. Five patients had documented Waldenström's macroglobulinemia (WM). Three architectural patterns were observed. Pattern A (seven of 20) showed open sinuses, small follicles, and hemosiderosis; pattern B (four of 20) showed hyperplastic follicles; and pattern C (nine of 20) showed diffuse effacement. Epithelioid histiocytes were prominent in patterns B and C but absent in A. Cytologically, six of 20 were polymorphous with 10% to 40% transformed cells; 14 of 20 were lymphoplasmacytic. Five cases showed minor foci of monocytoid B cells. One case showed a composite histology of LLI and small lymphocytic lymphoma. Amyloid was present in two cases. All cases were CD20 and/or CD79a immunoreactive, with two of 20 positive for CD43. Twelve cases were kappa monoclonal and eight cases were lambda monoclonal. Twelve of 17 cases that could be evaluated were positive for IgM and five were positive for IgG. All cases were negative for CD5 and CD23 with the exception of the one case with a composite histology. Eleven of 20 patients with available follow-up died of disease (median, 48 months), and eight of 20 are alive with disease at a follow-up of 6 months to 2 years. LLI does appear to represent a distinct clinicopathologic entity even though it shows morphologic heterogeneity and overlapping features with marginal zone B-cell lymphoma and small lymphocytic lymphoma. Recognition of LLI is important because the overall prognosis may be worse than for other types of small B-cell lymphomas.

Mantle cell leukemia, prolymphocytoid type: a rarely described form

Leukemic manifestations of mantle cell lymphoma are seen in a minority of cases, usually associated with extensive tumor. Usually the neoplastic cells in the peripheral blood resemble mantle cells with a mature chromatin pattern and irregular nuclear contours, or less frequently with a more "blastic" chromatin pattern. A prolymphocytic leukemia with t(11;14)(q13;q32) has previously been reported; however, a complete flow cytometric immunophenotypic profile was lacking. Mantle cell leukemia, prolymphocytoid type with complete flow cytometric data has not previously been described and is the purpose of this report. We report such a case in a 90 year-old female who presented with an elevated white blood cell count. The diagnosis was based on flow cytometric immunophenotyping and the cytomorphology of the peripheral blood combined with cyclin D1 immunohistochemical staining of the bone marrow. We describe our findings and her clinical course in order to heighten awareness of this previously rarely described entity.

Large cell lymphoma transformation of chronic lymphocytic leukemia/small lymphocytic lymphoma. A flow cytometric analysis of seven cases

We studied 7 cases of large cell transformation of chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) immunophenotyped by multiparameter flow cytometry. The 6 women and 1 man ranged in age from 45 to 91 years. All had previous or concurrent evidence of CLL/SLL. Morphologic features and sites of involvement of the diffuse large B-cell lymphoma (DLBCL) were heterogeneous; 2 cases had paraimmunoblastic morphologic features. Six DLBCLs had an immunophenotype consistent with CLL: CD19+, CD5+, CD23+, and FMC7 negative (3 cases) or very dim (2 cases); 1 case was not studied for FMC7. CD20 was dim in 3 of these, moderate to bright in 2, and variable in 1. Surface immunoglobulin was dim in 2 cases and moderate or bright in 4. Five of 6 expressed CD38. Comparison with the immunophenotypes of the previous or coexistent CLL/SLL (4 of 6 cases) revealed minor modulations in antigen expression but no major alterations. The seventh DLBCL lacked CD5 expression, but otherwise had immunophenotypic features similar to CLL. These findings indicate that DLBCL arising in CLL/SLL tends to retain a CLL immunophenotype, in contrast with de novo CD5+ large cell lymphomas that uncommonly express such a phenotype.

CD5+ follicle center lymphoma. Immunophenotyping detects a unique subset of "floral" follicular lymphoma

The "floral" variant of follicle center lymphoma (FCL) may be confused with progressive transformation of germinal centers or lymphocyte predominance Hodgkin lymphoma. Immunohistochemistry and gene rearrangement studies are usually sufficient to differentiate among these entities. We present 11 cases of floral FCL that were evaluated at our institution by flow cytometry, immunohistochemistry, or both and by polymerase chain reaction-based molecular analysis. In 4 cases, the neoplastic B cells coexpressed CD5 antigens; 3 of these 4 cases also were CD10+, and all demonstrated rearrangement within the bcl-2 locus. These findings demonstrate that a subset of floral FCL is CD5+. Recognition of this immunophenotype is important to avoid misdiagnosis of nodular variants of small lymphocytic lymphoma and mantle cell lymphoma. Studies suggest that expression of CD5 by neoplastic germinal center cells might result from alterations of the follicular microenvironment and/or inappropriate B-cell responses to cytokine networks.

Pathologic diagnosis of mantle cell lymphoma

Mantle cell lymphoma (MCL) is a clinicopathologic entity with distinctive morphologic and immunophenotypic features and a characteristic cytogenetic abnormality, the t(11;14)(q13;q32). Although MCL was recognized over 30 years ago, a lack of consensus regarding its morphologic features precluded its inclusion into non-Hodgkin's lymphoma (NHL) classification schemes until relatively recently. An accurate diagnosis of MCL is of great importance, since this tumor generally carries a poor prognosis and requires more aggressive and novel treatment regimens. In this article, we briefly overview the clinical features of MCL and then focus on the pathologic diagnosis of MCL, emphasizing morphologic findings and various ancillary techniques useful in the diagnostic workup. Involvement of lymph nodes and other sites, such as the spleen, liver, gastrointestinal tract, Waldeyer's ring, bone marrow, peripheral blood, and cerebrospinal fluid are reviewed. The diagnosis of high-grade variants of MCL is a particular challenge, as these tumors exhibit a broad spectrum of morphologic findings that can be misinterpreted as other types of NHL. The molecular basis of MCL is also briefly reviewed to highlight the biologic role of the t(11;14) and cyclin D1 overexpression in this tumor and the value of immunophenotypic and molecular methods for their detection as diagnostic aids.

CD5+ true SLL/CLL with plasmacytic differentiation and an unusual 1p36 translocation: case report and review of the literature

Lymphoplasmacytic lymphoma (LPL) and small lymphocytic lymphoma/chronic lymphocytic leukemia (SLL/CLL)are distinct clinicopathologic entities. Although some cases of SLL/CLL may show plasmacytic differentiation and be associated with monoclonal immunoglobulin in serum, such cases appear to be very rare, and if plasma cell differentiation were marked, differentiation of SLL/CLL from LPL could be difficult. We report a rare case of true CD5-positive small lymphocytic lymphoma/chronic lymphocytic leukemia with unequivocal plasmacytic differentiation. This case also showed an abnormality of chromosome 1p36 not previously described in small lymphocytic lymphoma/chronic lymphocytic leukemia.

Histological features of ocular adnexal lymphoma (REAL classification) and their association with patient morbidity and survival

BACKGROUND

The histological characteristics of ocular adnexal lymphomas have previously provided only a limited guide to clinical outcome for affected patients. This clinicopathological relation was re-examined using the Revised European American Lymphoma (REAL) system to classify the tumours in a large cohort of patients.

METHODS

The biopsies and clinical follow up data for 192 patients with ocular adnexal lymphoma were reviewed, the biopsies being regraded in accordance with the REAL classification. For each of five histological groups, logistic regression analysis was used to determine the odds ratios (OR) for the presence of systemic disease at the time of orbital diagnosis and Cox regression analysis was used to assess the hazard ratios (HR) for disseminated disease and lymphoma related death. For 108 patients in whom extraorbital spread occurred, the histological category of lymphoma was compared with the sites of dissemination.

RESULTS

At presentation, the frequency of previous or concurrent extraorbital disease increased from marginal zone lymphoma (OR 1.0), diffuse lymphoplasmacytic/lymphoplasmacytoid lymphoma (OR 2.3), follicle centre lymphoma (OR 3.8), diffuse large B cell lymphoma (OR 4.0) to other histological lymphoma variants (OR 26.8). For all histological types, the estimated risk of extraorbital disease and lymphoma related death continued for many years and the proportion of patients with at least one extraorbital recurrence after 5 years was 47% for MZL, 48% for LPL, 64% for FCL, 81% for DLCL, and 95% for other lymphoma variants. The corresponding estimated rates for 5 year lymphoma related mortality were 12%, 19%, 22%, 48%, and 53% respectively.

CONCLUSIONS

Patients with ocular adnexal lymphoma can be classified by REAL into five distinct groups, which show a progressive increase in the risks of extraorbital disease at diagnosis, of disease dissemination with time, and of tumour related death.

Small B-cell lymphoproliferative disorders: an overview of diagnostic approach

Despite their common origin from the B-cell mature lymphoid system, small B-cell lymphomas/leukaemias represent in fact an heterogeneous group of diseases. Recent advances in immunohistochemistry and molecular techniques have improved our knowledge of the immune system and lymphoid neoplasms. An international consensus has been recently reached among pathologists and clinicians, that recognises clinico-pathological entities which are defined by a combination of morphological, immunophenotypical, genetic and clinical features. In each entity, a range of histological grade and clinical aggressiveness can be encountered. Recognition of these entities, combined with clinical prognostic factors has clinical implications in terms of response to treatment and prognosis. The purpose of this paper is to focus on a practical approach, either clinical or pathological, of the diagnosis of small B-cell lymphoma/leukaemia.

Extranodal marginal zone B-cell lymphoma of the skin: a morphologic and immunophenotypic study of 11 cases

Extranodal marginal zone B-cell lymphoma (MZBL) is a recently recognized low-grade lymphoma that has been well described in other organs such as the stomach and salivary gland. It has only recently been described in skin, where it may be difficult to distinguish from reactive processes and other types of B-cell lymphoma such as follicle center lymphoma. These cases may have been classified as pseudolymphomas in the past. Extranodal MZBL was referred to as mucosa-associated lymphoid tissue (MALT) lymphoma before the Revised European-American Classification of Lymphoid Neoplasms was published in 1994. Important histologic features that aid in the diagnosis of MALT lymphoma are atypical lymphocytes (centrocyte-like and monocytoid B cells) often admixed with plasmacytoid lymphocytes, a prominent plasma cell component, lymphoepithelial lesions, intranuclear inclusions (Dutcher bodies), and reactive germinal centers that may be colonized by neoplastic cells. Immunophenotypic studies demonstrating a B-cell phenotype, light chain restriction, coexpression of CD43, and staining of atypical lymphocytes with bcl-2 support a diagnosis of MALT lymphoma. We studied 11 cases of extranodal MZBL of the skin from the Armed Forces Institute of Pathology files. There were six women and five men ranging in age from 30 to 69 years (median, 54 years). The anatomical sites included the trunk, head and neck areas, and upper extremities. There were no other sites of disease besides the skin in any of the cases. The follow-up period ranged from 5 months to 8 years (median, 24 months). Histologic results included an atypical lymphoid infiltrate with B-cell phenotype, reactive germinal centers, and a variable plasma cell component in all cases. No Dutcher bodies or lymphoepithelial lesions were noted. Extranodal MZBL of skin is a diagnostic challenge because of a heterogeneous cellular infiltrate that may be interpreted as a reactive process. The most significant neoplasm with which it is confused is follicular lymphoma. It is important to recognize the characteristic histologic and immunophenotypic features of extranodal MZBL so that the appropriate therapeutic approach may be applied.

The diagnosis of low-grade peripheral B-cell neoplasms in bone marrow trephines

The aim of this study was to establish how effective is the use of immunohistochemistry on formalin-fixed bone marrow in diagnosing low-grade B-cell neoplasms. We investigated a series of 41 consecutive patients with bone marrow involvement for whom no other diagnostic tissues were available. The sections were stained with the following antibodies: CD3, CD20, CD79a, CD5, CD10, CD23, anti-cyclin D1 and kappa and lambda light chains. Antigen retrieval was performed using either a microwave oven or a pressure cooker. Labelling was performed with an avidin-biotin-peroxidase labelling system. A final diagnosis was reached in 37 out of 41 cases (90%): B-chronic lymphocytic leukaemia (15 cases), follicular lymphoma (10 cases), mantle-cell lymphoma (eight cases) and lymphoplasmacytoid lymphoma/immunocytoma (four cases). In the remaining four cases, a generic diagnosis of low-grade B-cell neoplasm was made. The immunophenotyping of formalin-fixed marrow is a useful technique for diagnosing most of the low-grade B-cell neoplasms.

Monoclonal antibodies recognizing CD5, CD10 and CD23 in formalin-fixed, paraffin-embedded tissue: production and assessment of their value in the diagnosis of small B-cell lymphoma

AIMS

Assessment of the expression of antigens CD5, CD10 and CD23 can be of value in the differential diagnosis of small B-cell lymphoma. Correct subclassification is important since optimal treatment regimes differ between the subtypes. The aim of this study was to generate monoclonal antibodies recognizing these antigens in paraffin-embedded tissue and to assess their efficacy using a panel of cases of small B-cell lymphoma of various subtypes.

METHODS AND RESULTS

For each antibody synthetic recombinant protein and conventional murine hybridoma technology was employed. Monoclonal antibodies effective in formalin-fixed, paraffin-embedded tissue were successfully generated, designated NCL-CD5-4C7, NCL-CD10-270 and NCL-CD23-1B12, respectively. A series of 58 cases of small B-cell lymphoma including examples of each subtype (lymphocytic, follicle centre cell, mantle cell, marginal zone and lymphoplasmacytoid) was assembled and immunostaining for the respective antigens carried out using the monoclonal antibodies produced. Our results indicate that the antibodies are specific for their respective antigens and give the predicted phenotypic profile in the small B-cell lymphoma subtypes.

CONCLUSIONS

These novel monoclonal antibodies may be of value in routine diagnostic practice.

Expression of CD10, CD75 and CD43 in MALT lymphoma and their usefulness in discriminating MALT lymphoma from follicular lymphoma and chronic gastritis

AIMS

While it may be difficult to discriminate between chronic gastritis, MALT lymphoma and a gastric location of a nodal lymphoma using histology of small endoscopic biopsies alone, additional markers like CD10, CD75 and CD43 and proliferative activity may be of value. We assessed the expression of these antigens in MALT lymphoma and their usefulness in discriminating MALT lymphoma from follicular lymphoma and from gastritis.

METHODS AND RESULTS

Tissue samples of 38 patients with gastric MALT lymphoma were immunohistochemically stained for expression of CD10, CD75 and/or CD43. Proliferation index was scored using MIB-1 staining. Ten cases of nodal follicle centre B-cell lymphomas (n = 11) and 18 cases of high-grade MALT lymphoma (n = 22) showed moderate to high CD75 expression (25-100% positive cells). All tested low-grade MALT lymphomas (n = 9) and chronic gastritis (n = 6) were negative (0-25%) for CD75. All MALT lymphomas (n = 25) were negative for CD10. High-grade lymphomas show significantly higher proliferation indices (67% vs. 16%) than low-grade lymphomas. Only four of 26 MALT lymphomas were slightly positive for CD43. All gastritis biopsies (n = 4) were negative for CD43.

CONCLUSIONS

These data suggest that combining both CD10 and CD75 may be useful in discriminating between low-grade MALT, high-grade MALT lymphoma and extranodal location of follicular lymphoma. However, CD43 expression cannot in the majority of cases be used to distinguish between low-grade MALT lymphoma and gastritis.

Blastic mantle cell leukemia: a previously undescribed form

The leukemic phase of mantle cell lymphoma (mantle cell leukemia) is defined as an absolute lymphocyte count of greater than 4,000/microliter and characterized by the presence of relatively small, slightly irregular lymphocytes in the peripheral blood. Although a variant of mantle cell lymphoma with blastic morphsology exists and has been previously well described, a blastic morphologic variant of mantle cell leukemia has not been described. We report such a case in a 74-year-old male who presented with splenic rupture and an elevated white blood cell (WBC) count. The diagnosis was based on flow cytometric immunophenotyping and the cytomorphology of the peripheral blood.

Practical applications of immunohistochemistry in hematolymphoid neoplasms

Immunohistochemistry plays a key role in the diagnosis and classification of hematolymphoid neoplasms. New cell and lineage markers are constantly being discovered and added to the existing long list of antibodies. In this review article we provide general information and new applications of the commonly used hematolymphoid markers. We also discuss the features and applications of some newly discovered markers, such as ALK, fascin, granzyme/perforin, and tryptase. There is no universal "panel" for the diagnosis of hematolymphoid neoplasms. However, in this review article, we provide suggested panels for a given hematolymphoid neoplasm that is based on our experience and that reported in the literature.

Mucosa-associated lymphoid tissue lymphoma of the stomach: long term outcome after local treatment

BACKGROUND

Although antibiotic therapy is emerging as effective initial treatment for patients with gastric lymphoma of mucosa-associated lymphoid tissue (MALT), there is a subset of patients for whom antibiotics are ineffective or inappropriate. Surgical resection can be curative, but total gastrectomy may be required for the eradication of all disease. To identify the optimal nonantibiotic therapy for early stage gastric MALT lymphoma, the authors retrospectively evaluated the Massachusetts General Hospital experience with gastric MALT lymphoma.

METHODS

Disease patterns and treatment outcomes were retrospectively analyzed in data from 21 consecutive patients with gastric MALT lymphoma who were treated between 1978 and 1995 at the Massachusetts General Hospital.

RESULTS

Sixteen patients were Stage IE, and 5 were in higher stages. Treatment consisted of resection with or without radiation or chemotherapy (14 patients), radiation alone (4 patients), or radiation plus chemotherapy (2 patients). Thirteen Stage IE patients received local therapy only. The 10-year actuarial relapse free survival rate for Stage IE patients was 93%, with 1 relapse among 15 treated patients. Because the patient who relapsed was treated successfully with chemotherapy, the 10-year cancer free survival was 100%. Overall survival for Stage IE patients was 93% at 5 years and 58% at 10 years, with no deaths from lymphoma.

CONCLUSIONS

These data indicate that a high probability of long term remission can be achieved with only local treatment of patients with Stage I gastric MALT lymphoma. Preliminary results suggest that radiation therapy is well tolerated and effective and may well be the optimal nonantibiotic treatment for patients with localized gastric MALT lymphoma.

The cytomorphological spectrum of mantle cell lymphoma is reflected by distinct biological features

Mantle cell (centrocytic) non-Hodgkin's lymphoma (MCL) is a malignant tumour with unique biological features. The pathogenesis of MCL seems to be strongly associated with aberrant function of the cell cycle. 110 cases of MCL have been analysed for their cytomorphological features, mitotic and proliferation indices, bcl-1 rearrangements, p53 expression patterns and DNA content by both interphase cytogenetic as well as DNA flow cytometric analyses. According to cytomorphology, three subtypes were recognized: a common, a lymphoblastoid and a pleomorphic variant of MCL. Blastic MCL subtypes were characterized by distinctly elevated mitotic and proliferation indices, frequent bcl-1 rearrangements at the MTC locus, and overexpression of p53. The most interesting finding, however, was a striking tendency of blastoid MCL subtypes to harbour chromosome numbers in the tetraploid range, a feature clearly separating these neoplasms from other types of B-cell NHL and possibly being related to its unphysiological expression of cyclin D1. Although characterised by a uniform immunophenotype and common biological background, MCL shows a broad spectrum of morphological features ranging from small cell to blastic types, and this spectrum is mirrored by distinct biological features.

Clinical and pathologic characterization of mucosa-associated lymphoid tissue lymphoma of the head and neck

Mucosa-associated lymphoid tissue (MALT) has recently been recognized as a possible site of origin for low-grade lymphomas of the B-cell type. Though relatively rare, these MALT lymphomas may arise within several sites in the head and neck, and often present diagnostic and therapeutic challenges. We review 4 cases of primary MALT lymphoma of the head and neck, treated with surgical excision (3 cases), irradiation (2 cases), and chemotherapy (1 case), to further characterize this new subtype of head and neck malignancy. The mean time from onset of symptoms to histologic diagnosis was 15 months. Fine needle aspiration identified an atypical lymphoid infiltrate in only 1 of 3 patients. Immunohistochemical analysis was essential in establishing the diagnosis of MALT lymphoma in all 4 of the cases, and demonstrated characteristic negative staining for CD3, CD5, and CD43, positive staining for CD20, and monotypic staining for either kappa or lambda light chain immunoglobulin markers. All patients achieved complete remission after primary therapy, and all remain free of disease with follow-up ranging from 6 to 54 months (mean 33 months). The diagnosis of MALT lymphoma should be considered in cases of atypical lymphoid infiltrates in the head and neck, and increased awareness coupled with detailed immunohistochemical analysis is essential to securing an accurate diagnosis. Clinical remission of MALT lymphoma may be achieved with several modalities, but further study will be required to determine the long-term response to treatment.

Evaluation and management of the "new" lymphoma entities: mantle cell lymphoma, lymphoma of mucosa-associated lymphoid tissue, anaplastic large-cell lymphoma, and primary mediastinal B-cell lymphoma

Non-Hodgkin's lymphomas (NHL) represent a major health problem worldwide, and incidence has been on the rise continuously for the last few decades. It is estimated that approximately 55,000 new cases of NHL will be diagnosed in the United States in 1998 and that slightly fewer than 25,000 patients will die of treatment failure or recurrent disease. The rising incidence of NHL is related not only to the acquired immunodeficiency syndrome epidemic but to also a steady increase in the number of cases diagnosed in older patients without immunosuppression. The new pathologic classification of NHL (revised European-American lymphoma classification, REAL) developed by the International Lymphoma Study Group (ILSG) is already resulting in more accurate disease-specific epidemiologic and clinical investigations. These studies have brought a new awareness of the existence and the relative prevalence of discrete NHL subtypes that appear to predominate among patients in different populations according to age, sex, geographic distribution, and predisposing conditions. This developing database has also the potential to result in the discovery of specific environmental causes, predisposing genetic factors, and therapeutic approaches. Some of the entities defined in the REAL classification, such as follicular lymphomas, diffuse B large-cell lymphomas, and T-cell lymphoblastic lymphomas, were already well described in the older classification systems (Kiel and Working Formulation). Others, such as mantle cell lymphoma, (MCL) anaplastic large-cell lymphoma (ALCL), lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma), and primary mediastinal B-cell lymphoma (PMBCL) are relatively new members of the family, and accurate data on their clinicopathologic features and natural histories have only recently begun to emerge. This review presents in detail the most recent data on the clinical presentation of, diagnostic evaluation of, and treatment options for the most common of the new NHL entities: MCL, MALT lymphoma, CD30+ (Ki-1+) ALCL, and PMBCL. These four entities combined represent approximately 20% of all cases of NHL and exemplify well the broad clinicopathologic spectrum of NHL and the diagnostic and therapeutic challenges facing those who care for patients affected by these conditions.

Impact of hepatitis C virus infection on clinical features, quality of life and survival of patients with lymphoplasmacytoid lymphoma/immunocytoma

BACKGROUND

The non-Hodgkin's lymphoma (NHL) subgroup most frequently associated with hepatitis C virus (HCV) infection is the lymphoplasmacytoid lymphoma/immunocytoma (Lp-Ic). We have assessed the impact of the infection on the clinical features, quality of life and survival of HCV+ve Lp-Ic patients as compared to its impact in HCV-ve patients.

PATIENTS AND METHODS

Seventy patients with Lp-Ic consecutively observed over a six-year period were studied. Clinical, virological and histopathological features were recorded at diagnosis. Quality of life was assessed using a scoring system including disease-related symptoms, performance status, working ability, hospital admissions and therapies required.

RESULTS

Eighteen patients (26%) with HCV infection were identified. Significant differences between those patients and the HCV-ve group included number of symptomatic patients, Hb levels, serum protein levels, entity of the IgM monoclonal component, number of patients with cryoglobulins and with organ (liver, kidney) involvement, and entity and pattern of bone marrow infiltration. Survival rates were similar (P = 0.8383), but the quality-of-life score was significantly worse for the HCV+ve patients (P = 0.002). All anti-HCV Ab+ve patients tested positive for HCV RNA; genotype 2ac was detected in a significant proportion of cases.

CONCLUSIONS

This study confirms that HCV infection is present in about one-third of patients with Lp-Ic. HCV infection does not seem to affect the overall survival of patients with Lp-Ic, but it affects the clinical expression of the disease, so that the overall quality of life of HCV+ve patients is significantly worse.

Rituximab: a new therapeutic monoclonal antibody for non-Hodgkin's lymphoma

Rituximab is an effective single agent available for short-course outpatient treatment in low-grade NHL, particularly with follicular histology (IWF B-D), that offers a relatively nontoxic alternative to chemotherapy regimens currently available. Early indications are that retreatment is effective with similar levels of predictable adverse events to the initial course of therapy. Further development is awaited of regimens that combine rituximab with chemotherapeutic agents to enhance treatment efficacy without overlapping side effects in low-grade NHL as well as use in other CD20+ malignancies.

De Novo CD5+ Diffuse Large B-Cell Lymphomas Express VH Genes With Somatic Mutation

To clarify the cellular origin of de novo CD5+ diffuse large B-cell lymphoma (CD5+ DLBL), particularly in comparison with other CD5+ B-cell neoplasms such as chronic lymphocytic leukemia (CLL) and mantle cell lymphoma (MCL), we analyzed the nucleotide sequence of the Ig heavy chain variable region (IgVH) genes of de novo CD5+ DLBL cases. All 4 cases examined had extensive somatic mutations in contrast with CLL or MCL. The VH gene sequences of de novo CD5+ DLBL displayed 86.9% to 95.2% homology with the corresponding germlines, whereas those of simultaneously analyzed CLL and MCL displayed 97.6% to 100% homology. The VH family used was VH3 in 1 case, VH4 in 2 cases, and VH5 in 1 case. In 2 of 4 examined cases, the distribution of replacement and silent mutations over the complementarity determining region and framework region in the VH genes was compatible with the pattern resulting from the antigen selection. Clinically, CD5+DLBL frequently involved a variety of extranodal sites (12/13) and lymph node (11/13). Immunophenotypically, CD5+ DLBL scarcely expressed CD21 and CD23 (3/13 and 2/13, respectively). These findings indicate that de novo CD5+ DLBL cells are derived from a B-1 subset distinct from those of CLL or MCL.

CD5+ low-grade marginal zone B-cell lymphomas with localized presentation

Marginal zone B-cell lymphomas (MZBCLs) are low-grade lymphomas that characteristically lack CD5 expression. However, rare cases of MZBCL have been described in which the lymphomatous B cells coexpress CD5 (CD5+ MZBCL). In 7 of 9 reported CD5+ MZBCLs, there was evidence of widespread disease. We report four additional cases of CD5+ MZBCL. Three cases were low-grade B-cell lymphomas of mucosa-associated lymphoid tissue (MALT) involving the lungs, the conjunctiva (bilateral), and the uterus. The remaining case represented a monocytoid B-cell lymphoma involving a posterior cervical lymph node. Southern blot hybridization did not show rearrangements of bc11 or bc12 in the three cases analyzed. All four patients had localized disease and normal peripheral blood counts. Staging of bone marrow biopsies from three patients did not show evidence of bone marrow involvement. The remaining patient had bilateral conjunctival lesions that were present for 15 years without progression. These four additional cases of CD5+ MZBCL show that this group of low-grade B-cell lymphomas occasionally may exhibit an atypical phenotype. Furthermore, in this study, the CD5+ MZBCLs were clinically localized at presentation, in contrast to most other reported cases, which have had dissemination to bone marrow or peripheral blood.

Mantle cell lymphoma: clinical features, treatment and prognosis of 94 patients

Mantle cell lymphoma (MCL) is a subtype of B-cell non-Hodgkin's lymphoma recently recognised as a distinct disease entity. Little is known about the prognostic factors and optimal treatment of MCL. The aim of this study was to analyse retrospectively the clinical features and effect of treatment in 94 MCL patients diagnosed and treated in one centre between 1980 and 1996, and to find out different factors influencing the treatment results and prognosis. The median age of the patients was 66 years, and 77% were over 60 years old. Of the patients, 76% had advanced disease, the performance status (PS) was WHO 0-1 in 86%, and B symptoms were present in 35% of the cases. Bone marrow infiltration was found in 61% and overt leukaemia in 12% of the patients. Of the patients, 47% achieved complete remission with first- or second-line therapy. The median duration of remission, time to treatment failure (TTF), and survival were 28, 18, and 41 months, respectively. In multivariate analyses, age, stage and leukaemic disease were significantly associated with TTF, and age, stage, leukaemic disease and lactate dehydrogenase (LDH) with survival. Long-term prognosis is poor in MCL. None of the conventional chemotherapies seems curative. A prospective randomised trial should be made to evaluate the benefit of anthracycline-containing regimens in MCL.