Salivary gland lymphoid infiltrates associated with lymphoepithelial lesions: a clinicopathologic, immunophenotypic, and genotypic study

Molecular B-cell clonality assay in minor salivary glands as a useful tool for the lymphoma risk assessment in Sjögren's syndrome

OBJECTIVES

Non-Hodgkin's lymphoma (NHL) risk assessment is crucial in Sjögren's syndrome (SS). We studied the prevalence of clonal immunoglobulin gene rearrangements in minor salivary glands (MSG) and their correlations with lymphoma occurrence and with previously established NHL predictors.

METHODS

Molecular B-cell expansion was studied in fresh-frozen MSG of 207 patients with either suspected SS or with suspected lymphoma during SS, using a standardised multiplex PCR assay combined with heteroduplex analysis by microcapillary electrophoresis. The assignation of clonal cases was based on EuroClonality consortium guidelines.

RESULTS

Among 207 studied patients, 31 (15%) had MSG monoclonal B-cell infiltration. Monoclonality was significantly more frequent in patients with SS (28/123, 22.8%) compared with patients without SS (3/84, 3.6%, P<0.001). Monoclonal B-cell infiltration in MSG of SS patients correlated significantly with ongoing salivary gland NHL, salivary gland swelling, CD4+ T-cell lymphopenia, rheumatoid factor (RF) activity, low complement levels and type 2 mixed cryoglobulinemia. The accumulation of biological risk factors was associated with a higher rate of MSG B-cell monoclonality given that patients with only positive RF had no probability of MSG B-cell monoclonality, RF-positive patients with 1 or 2 other risk factors had a 25.0% and 85.7% probability of MSG B-cell monoclonality, respectively.

CONCLUSION

The detection of MSG monoclonal B-cell expansion by this easy-to-perform molecular assay is useful, both at the time of diagnosis and during the course of SS. Monoclonal B-cell expansion is associated with a subset of SS patients presenting either ongoing lymphoma or other established lymphoma predictive factors.

The FcεRI signaling pathway is involved in the pathogenesis of lacrimal gland benign lymphoepithelial lesions as shown by transcriptomic analysis

This study aimed to analyze the role of the FcepsilonRI (FcεRI) signaling pathway in the pathogenesis of benign lymphoepithelial lesion of lacrimal gland (LGBLEL). Transcriptomic analysis was performed on LGBLEL and orbital cavernous hemangioma (CH) patients diagnosed via histopathology in Beijing Tongren Hospital, Capital Medical University, between July 2010 and October 2013. Four LGBLEL and three orbital CH patients, diagnosed between October 2018 and August 2019, were randomly selected as experimental and control groups, respectively. RT-PCR, immunohistochemical staining, and western blotting were used to verify genes and proteins related to the FcεRI signaling pathway. Transcriptomic analysis showed that the FcεRI signaling pathway was upregulated in the LGBLEL compared with the CH group. The mRNA expression levels of important genes including SYK, p38, JNK, PI3K, and ERK were significantly increased in the LGBLEL group (P = 0.0066, P = 0.0002, P = 0.0003, P < 0.0001, P < 0.0001, respectively). Immunohistochemical staining results showed that SYK, p38, and ERK were positively expressed in LGBLEL, while JNK and PI3K were not. The protein contents of P-SYK, P-p38, P-JNK, P-PI3K, and P-ERK were significantly higher in the LGBLEL than in the CH group (P = 0.0169, P = 0.0074, P = 0.0046, P = 0.0157, P = 0.0156, respectively). The FcεRI signaling pathway participates in the pathogenesis of LGBLEL.

Light Chain-Restricted Plasmacytoid Cells in Hyperplastic Germinal CentersA Clinicopathologic Investigation

OBJECTIVES

Follicular hyperplasias (FHs) with light chain-restricted (LCR) plasmacytoid/plasma cells (PCs) within germinal centers (GCs) based on immunohistochemistry (IHC)/in situ hybridization (ISH) can potentially lead to diagnostic error. This study aims to better characterize such cases, including their clinical implications.

METHODS

LC expression by IHC/ISH was quantitatively assessed in GCs of 17 FHs with LCRGCs. BCL2, CD10, BCL6, BCL2, immunoglobulin (Ig) heavy chains, IgG4, and Epstein-Barr encoding region stains were performed. In total, 8 cases had polymerase chain reaction (PCR)-based clonality studies.

RESULTS

All cases showed FH, including 4 with progressively transformed GCs (PTGCs); 0.8% to 52% (median, 21%) of the GCs were LCR; 13 of 17 had both κ- and λ-LCRGCs, and 4 of 17 had only κ-LCRGCs; 7 of 16 had prominent intrafollicular IgG4-positive cells. One case demonstrated BCL2-positive cells in focal LCRGCs but lacked BCL2 rearrangement. B-cell monoclonality was demonstrated in 3 of 8 cases (only after microdissection). Seven patients had autoimmune disorders, and 1 had had a transplant. Three patients had a history of lymphoma, 1 developed lymphoma, and 1 developed lymphomatoid granulomatosis subsequently.

CONCLUSIONS

FHs with LCRGC by IHC/ISH are typically not associated with the development of lymphoma, even though they can express BCL2 and show monoclonality by PCR. They may be associated with increased intrafollicular IgG4-positive cells, PTGC, and autoimmunity.

Mantle cell lymphoma, malt lymphoma, small lymphocytic lymphoma, and follicular lymphoma of the oral cavity: An update

BACKGROUND

Although uncommon, mature small B-cell lymphomas may arise in the oral/maxillofacial area and oral pathologists must be aware of the key characteristics of these neoplasms to perform an accurate diagnosis. In this manuscript, we attempted to integrate the currently available data on the clinicopathological features of follicular lymphoma (FL), mantle cell lymphoma (MCL), extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT-L), and chronic lymphocytic leukemia/ small lymphocytic lymphoma (CLL/SLL) affecting these anatomical regions.

METHODS

An updated descriptive literature review was carried out and a detailed electronic search was done in multiple databases to gather all cases affecting the oral/maxillofacial region and palatine tonsils.

RESULTS

We observed that MALT-L was the most frequently reported subtype, followed by FL, MCL, and CLL/SLL. The palate was affected in a high proportion of cases and the most usual clinical presentation was an asymptomatic swelling. MALT-L and CLL/SLL neoplastic cells were strongly associated with small salivary glands. FL showed no gender preference, while MCL and CLL/SLL were more prevalent in males and MALT-L in females. Overall, cases were more common in elderly individuals. Patients' treatment and outcome varied, with MCL being the most aggressive neoplasm with a dismal prognosis in comparison to FL and MALT-L.

CONCLUSION

Despite the poor documentation in many of the cases available, especially regarding the microscopic and molecular features of tumors, this review demonstrated that the oral mature small B-cell lymphomas investigated share similar clinical presentation, but carry different prognostic significance, demanding an accurate diagnosis.

Clonality testing in the lymph nodes from dogs with lymphadenomegaly due to Leishmania infantum infection

INTRODUCTION

In southern European countries, multicentric lymphoma and leishmaniosis are the main differential diagnoses in dogs presented with generalized lymphadenomegaly. The cytological examination is in some cases inconclusive and polymerase chain reaction (PCR) for antigen receptor rearrangement (PARR) has become a common method to confirm or rule out a lymphoproliferative neoplasia. According to the literature, leishmaniosis may lead to clonal arrangements and therefore to a false diagnosis of lymphoma, but this assumption is made from a single leishmania infected dog. Therefore, the objective of this study was to prospectively evaluate results from PARR in dogs with lymphadenomegaly due to clinical leishmaniosis at the moment of diagnosis.

MATERIALS AND METHODS

31 dogs with a diagnosis of leishmaniosis based on the LeishVet guidelines were included in the study. Samples from enlarged lymph nodes were taken for cytological examination, clonality testing and Leishmania infantum PCR.

RESULTS

All 31 dogs had medium to high positive antibody titers against Leishmania spp. and 30/31 had a positive Leishmania PCR from the lymph node. A polyclonal arrangement for B cells (immunoglobulin heavy chain gene) and T cells (T-cell receptor gamma chain gene) antigen receptors was found in 28/31 dogs. Two out of 31 dogs showed a monoclonal arrangement for Ig with high (1:2) and low (1:7) polyclonal background respectively; and one of the 31 dogs showed a monoclonal arrangement for T cell receptor with low (1:3) polyclonal background.

CONCLUSION

Infections with Leishmania infantum resulted in clonal rearrangement, and therefore in a possible false diagnosis of lymphoma, in 3 out of 31 dogs (9.7%). Although, PARR is a useful method to differentiate lymphoma from reactive lymphoid hyperplasia in dogs with leishmaniosis, mono-/biclonal results should be interpreted carefully, especially in the presence of any degree of polyclonal background, and together with other clinicopathological findings.

Monocytoid B cell lymphoma: A case report and evaluation

Lymphomas are a group of malignant blood cell tumors that develop from lymphocytes. Two main categories of lymphomas are Hodgkin and non-Hodgkin lymphomas (NHL), of which 90% are of the NHL type. The objectives of classifying is to help in the identification of homogenous group of well-defined entities and facilitating the recognition of uncommon diseases that further require classification as it affects prognosis and therapeutic implications. Nodal marginal zone lymphoma, also known as monocytoid B-cell lymphoma (MBCL), is an uncommon form of lymphoma representing 1.5%-1.8% of lymphoid neoplasms, with only rare reports in the literature that have attempted morphologic or immunophenotypic characterization. Specific markers for MBCLs are still lacking, so its diagnosis is based on exclusion of other small B-cell lymphomas. This article illustrates a case report of MBCL highlighting the intricacies and difficulties involved in establishing a diagnosis.

B cell receptor signaling pathway involved in benign lymphoepithelial lesions of the lacrimal gland

AIM

To detect the expression of B cell receptor signaling pathway (BCRSP) in lacrimal gland benign lymphoepithelial lesions (LGBLEL).

METHODS

Gene microarray was used to compare whole-genome expression in lacrimal gland tissues from LGBLEL patients to tissues from orbital cavernous hemangioma (control tissues). Expression of BCRSP was confirmed by polymerase chain reaction (PCR) and immunohistochemistry.

RESULTS

The expression of 22 genes of the BCRSP increased significantly in LGBLEL patients. PCR analysis showed that CD22, CR2, and BTK were all highly expressed in LGBLEL tissues. Immunohistochemical analysis showed that CR2 protein was present in LGBLEL, but CD22 and BTK proteins were negative. CR2, CD22, and BTK were not observed in the orbital cavernous hemangiomas with either PCR or immunohistochemistry.

CONCLUSION

BCRSP might be involved in the pathogenesis of LGBLEL.

Küttner’s Tumor of Salivary Glands Resembling Marginal Zone B-cell Lymphoma of the MALT Type: A Histopathologic and Immunohistochemical Study of 7 Cases

Küttner’s tumor is a benign inflammatory process of the submandibular gland that presents as a hard mass mimicking a malignant neoplasm clinically. The histologic feature varies according to stage of evolution and severity of inflammation. We report here 7 cases of Küttner’s tumor that morphologically resemble primary salivary gland marginal zone B-cell lymphoma of the mucosa-associated lymphoid tissue (MALT) type. Histologically, the lobular architecture was distorted and the septa showed sclerosis. There was a dense lymphoplasmacytoid infiltration with lymphoid follicle formation accompanied by loss of acini and ducts. In 4 cases, a few salivary gland ducts contained the lymphoid cells within the epithelium. However, a true lymphoepithelial lesion was observed in none of the 7 cases. Immunohistochemical study demonstrated a disrupted follicular dendritic cell network, which is a characteristic finding of follicular colonization of MALT-type lymphoma. In 6 cases, there were a few small foci of lymphocytes somewhat resembling centrocyte-like cells of MALT-type lymphoma. However, immunohistological study demonstrated the mixed nature of the cells resembling centrocyte-like cells. Moreover, the polytypic nature of B lymphocytes was demonstrated by immunohistochemistry and polymerase chain reaction.

Parotid Gland Biopsy, the Alternative Way to Diagnose Sjögren Syndrome

Salivary gland biopsy is a technique broadly applied for the diagnosis of Sjögren syndrome (SS), lymphoma in SS, and connective tissue disorders (sarcoidosis, amyloidosis). In SS characteristic histology findings are found, including lymphocytic infiltration surrounding the excretory ducts in combination with destruction of acinar tissue. In this article the main techniques are described for taking labial and parotid salivary gland biopsies with respect to their advantages, postoperative complications, and usefulness for diagnostic procedures, monitoring disease progression, and evaluation of treatment.

Immunohistochemical Markers of Soft Tissue Tumors: Pathologic Diagnosis, Genetic Contributions, and Therapeutic Options

After ~30 years of widespread usage, immunohistochemistry (IHC) has become a standard method of diagnosis for surgical pathology. Because of the plethora of diagnoses and often subtle nature of diagnostic criteria, IHC finds particular utility in soft tissue tumors. The use of progressively small amounts of tissue for diagnosis highlights the importance of this method. The sensitivity and crispness of IHC stains have progressively improved with the advent of new techniques. Traditionally, IHC detects cell-typic markers that characterize cell phenotypes, such as chromogranin for neuroectodermal tissue, myogenin for skeletal muscle, and cytokeratin for epithelium. However, the advent of genetic discoveries have led to IHC testing for detection of fusion gene products or overexpressed oncogenes associated with deletions and mutations. Proliferation-based markers such as Ki-67 can also be used for prognosis and grading, but more standardization is needed. Development of monoclonal antibody-based pharmaceuticals, such as imatinib or crizotinib, holds the promise of tailored anticancer therapy. IHC thus has assumed importance not only for diagnosis but also for guidance of personalized medicine.

Primary Extranodal Lymphomas of Lip - A Rare Manifestation in Sjogren's Syndrome

Sjogren's syndrome (SS) is a chronic autoimmune disorder which is characterized by lymphocyte-mediated destruction of exocrine glands, which produces the classical symptoms of dry eyes and dry mouth, which is referred to as primary SS or the Sicca complex. When it is associated with another autoimmune disease such as rheumatoid arthritis or lupus erythematosus, the condition is termed as secondary SS. One of the known major complications in patients with Sjogren's syndrome is the occurrence of Non-Hodgkin's lymphoma of B cell type. It is not uncommon for malignant lymphomas to occur in head and neck region at nodal and sometimes, extranodal sites. However, only rarely may they involve the oral cavity primarily. This case report describes a rare occurrence of isolated extranodal lymphomas in the upper and lower lips of a patient, which clinically resembled a mucocele, and eventually was diagnosed as lymphoma which was associated with Sjogren's syndrome, thereby stressing the importance which was played by an oral diagnostician.

Florid reactive lymphoid hyperplasia (lymphoma-like lesion) of the uterine cervix

Lymphoma-like lesion (LLL) of the female genital tract is an older term in the literature that describes a florid reactive lymphoid proliferation that can be misinterpreted as lymphoma. Multiple causes of LLL have been suggested but most cases remain unexplained. We describe the clinicopathologic features of 6 patients with LLL involving the uterine cervix. Five patients presented with abnormal Papanicolaou test (Pap smear), and 3 patients had a biopsy procedure performed prior to detection of LLL in a loop electrosurgical excision procedure (LEEP). In each specimen, surface epithelial erosion was associated with a superficial, polymorphous lymphoid infiltrate with numerous scattered large cells, without cellular necrosis or sclerosis. Squamous dysplasia was present in 4 patients. Immunohistochemical studies revealed a mixed population of B- and T-lymphoid cells. T-cells were more numerous but B-cells and formed aggregates or sheets in areas. The large cells were predominantly B-cells positive for CD20 and negative for CD3 in all cases. CD30 was positive 3 cases, and Epstein-Barr virus-encoded RNA was positive in 3 cases. Assessment for clonality in 1 patient using polymerase chain reaction (PCR) methods revealed monoclonal immunoglobulin heavy chain (IgH) gene rearrangements. At last clinical follow-up there was no evidence of progressive or systemic disease. We conclude that LLL of the cervix has a number of etiologies and that a prior surgical procedure, present in 3 patients in this study, is another possible etiology. As has been reported by others, monoclonal IgH gene rearrangements can be detected in this entity which has a benign clinical course.

Treatment of mucosa-associated lymphoid tissue lymphoma in Sjogren's syndrome: a retrospective clinical study

OBJECTIVE

To retrospectively analyze the clinical course of patients with mucosa-associated lymphoid tissue (MALT)-type lymphoma of the parotid gland and associated Sjögren's syndrome (SS).

METHODS

All consecutive patients with SS and MALT lymphoma (MALT-SS) diagnosed in the University Medical Center Groningen between January 1997 and January 2009 were analyzed. Clinical course and treatment outcome of SS and MALT lymphoma were evaluated.

RESULTS

From a total of 329 patients with SS, 35 MALT-SS patients were identified, with a median followup of 76 months (range 16-153 mo). MALT lymphoma was localized in the parotid gland in all cases. Treatment consisted of "watchful waiting" (n = 10), surgery (n = 3), radiotherapy (n = 1), surgery combined with radiotherapy (n = 2), rituximab only (n = 13), or rituximab combined with chemotherapy (n = 6). Complete response was observed in 14 patients, partial response in 1 patient, and stable disease in 20 patients. In 6 of 7 patients with initially high SS disease activity (M-protein, cryoglobulins, IgM rheumatoid factor > 100 KIU/l, severe extraglandular manifestations), MALT lymphoma progressed and/or SS disease activity increased after a median followup of 39 months (range 4-98 mo), necessitating retreatment. Only 1 patient with MALT who had low SS disease activity showed progression of lymphoma when left untreated.

CONCLUSION

An initially high SS disease activity likely constitutes an adverse prognostic factor for progression of lymphoma and/or SS. Such patients may require treatment for both MALT lymphoma and SS. In SS patients with localized asymptomatic MALT lymphoma and low SS disease activity, a "watchful waiting" strategy seems justified.

[Progression of nodal marginal zone lymphoma into diffuse large B cell lymphoma in a patient with Sjögren's syndrome]

INTRODUCTION

Sjögren's syndrome is a chronic autoimmune disorder carrying the risk of the development of non-Hodgkin's lymphoma, most frequently marginal zone lymphoma.

CASE OUTLINE

A 66-year-old male patient with Sjögren's syndrome, after a year of the disease, developed a nodal marginal zone lymphoma with lymphoma cells in peripheral blood which had the following immunophenotype: CD19, CD20, CD22, CD19/kappa, CD79b+. After six cycles of chemotherapy according to CHOP protocol (cyclophosphamide, doxorubicin, vincristine and prednisone) disease remission was achieved lasting four months, followed by enlargement of lymph nodes in all areas (generalized lymphadenopathy), splenomegaly and enlargement of the right parotid gland. Bone marrow biopsy and histology confirmed lymphoma of the same morphologic and immunohistochemic profile. Biopsy of a very enlarged hard right parotid gland, by using histology and immunohistochemistry, showed lymphoid tumour tissue with blast appearance and a number of nucleoli corresponding to centroblasts and less to immunoblasts. Immunophenotypes of these cells were as follows: CD79alfa+, CD20+, CD3-, bcl-2-; proliferative activity measured with KI-67 was high rating 60%. Histology and immunohistochemistry showed the co-existence of a diffuse large B cell lymphoma with marginal zone lymphoma. In spite of aggressive chemotherapy treatment according to protocol ESHAP (Vepesid 200 mg i.v. on 1st and 2nd day and 100 mg on 3rd, 4th and 5th day; Cisplatin 20-20-10 mg on 1st to 4th day) the disease showed a progressive course.

CONCLUSION

In patients with Sjögren's syndrome, the possibility of lymphoma should be kept in mind and in suspected cases timely diagnostic and therapeutic measures should be undertaken.

Selected topics on lymphoid lesions in the head and neck regions

Lymphoid tissue located in the head and neck region include multiple regional lymph node chains as well as mucosa associated lymphoid tissue of the conjunctiva, buccal and nasopharyngeal cavities (Waldeyer's ring), and thyroid and salivary glands. This region is a rich source of antigenic stimuli including infectious agents coming from the outside environment. Many reactive conditions that affect lymphoid tissue in this region may mimic neoplasia. In fact, distinguishing between benign and malignant lymphoid proliferations in the head and neck region is a relatively frequent diagnostic challenge and in many instances, this distinction is not straightforward. It therefore behooves the practicing pathologist to be able to recognize the benign lymphoproliferative disorders that affect this region so as to effectively guide the appropriate clinical management of such patients. Kimura disease, Epstein Barr lymphadenitis, HIV associated salivary gland disease and chronic sialadenitis are benign conditions that not infrequently affect lymphoid tissue in the head and neck region and that share certain overlapping features with malignant lymphoma. In this brief review, we discuss these conditions and highlight clinicopathological features that may help distinguish them from neoplastic lymphoproliferations that may share similar features.

Cystic lymphoid hyperplasia of the parotid gland in HIV-positive and HIV-negative patients: quantitative immunopathology

BACKGROUND

Benign lymphoepithelial lesions of the parotid include a spectrum of disorders ranging from lymphoepithelial sialadenitis (LESA) of Sjögren syndrome to lymphoepithelial cysts (LEC) and both human immunodeficiency virus (HIV)-related and -unrelated cystic lymphoid hyperplasia (CLH). They share a common microscopic appearance characterized by epimyoepithelial islands and/or epithelial lined cysts in a lymphoid stroma. However, they differ greatly regarding their etiology, clinical presentation, and management.

OBJECTIVE

The purpose of this study was to establish specific immunophenotypic profiles for these diverse disease entities.

STUDY DESIGN

Four cases of HIV+ CLH, 5 cases of HIV- CLH, 3 cases of LESA of Sjögren syndrome, and 3 cases of sporadic LEC were quantitatively analyzed for distribution of lymphoreticular cell subpopulations, using antibodies against CD20, CD45RO, CD4, CD8, CD57, and CD68.

RESULTS

The cystic lesions in both the HIV+ and HIV- cases were microscopically analogous. However, a marked decrease in the interfollicular CD4:CD8 ratio was observed in all HIV+ CLH cases, which was statistically significant when compared with the HIV- cases (P = .02) and cases of LESA of Sjögren syndrome (P = .03). No significant differences regarding the distribution of CD20+ B lymphocytes in epithelial cyst lining or the interfollicular or follicular distribution of CD20+, CD45RO+, CD57+, and CD68+ cells were present among the different groups.

CONCLUSION

Analysis of the interfollicular CD4:CD8 ratio may offer a simple immunophenotypic approach in the distinction of HIV+ from other lymphoepithelial lesions of the parotid gland, when HIV status is unknown and p24 immunohistochemistry is not readily available.

Clinical, histopathological and immunohistological study of lymphoid disorders in the parotid gland of patients with Sjögren's syndrome

BACKGROUND/AIM

Sjögren's syndrome is a chronic autoimmune systemic disease characterized by polyglandular tissue destruction, leading to keratoconjunctivitis sicca and xerostomia. These patients have 44-fold increased risk of developing salivary gland lymphoma, of which 80% are marginal zone (MALT) type. Having in mind that criteria for distinguishing benign lymphoepithelial lesions from MALT lymphoma are obscure, the aim of this study was to provide practical information that could be integrated into diagnostic practice.

METHODS

Among 32 parotidectomies, 27 cases were identified as having benign lymphoepithelial disorders and 5 cases low grade MALT lymphoma. Histological sections were stained routinely with hematoxylin and eosin (H&E and special stains. Immunohistochemical study was performed by LSAB2 method, by using primary antibodies for CD20, CD3, Kappa and Lambda light chains and Cytokeratin (Dako Denmark).

RESULTS

The 27 patients with Sjögren's sialoadenitis (22 women and 5 men), and 5 patients with MALT lymphoma (only women) were included in this analysis. According to the Ann Harbor Classification, all patients with MALT lymphoma had stage IE. Both groups of patients had an indolent clinical course, except permanent, rapid parotid enlargement in the patients with MALT lymphoma. Histologically, the periductal lymphoid infiltrate, gradually extended to the acini, completely replacing them by a sea of polyclonal lymphocytes, immunoblasts, germinal centers and plasma cells (confirmed immunohistochemically), but sparing the ducts and preserving lobular appearance. The histological feature of salivary gland MALT lymphoma included heterogeneous B-cell infiltrate that totally or subtotally had effaced the normal glandular structure. Malign lymphoepithelial lesions, representing infiltration of the ductal and epithelial structures by monoclonal neoplastic B-cells, positive for CD20, were highlighted by antibody to cytokeratin.

CONCLUSION

The optimal diagnosis of salivary gland MALT lymphoma requires careful integration of clinical, morphological and immunohistochemical results.

Florid reactive lymphoid hyperplasia of the lower female genital tract (lymphoma-like lesion): a benign condition that frequently harbors clonal immunoglobulin heavy chain gene rearrangements

Lymphoma-like lesions (LLL) of the lower female genital tract are florid reactive inflammatory processes that mainly occur in women in their reproductive years. Histologically, they are characterized by a dense lymphoid infiltrate with admixed large cells that is often suspicious for lymphoma. In contrast to lymphoma, however, they are superficial lesions that typically show surface erosion and a mixed lymphoid infiltrate and do not have evidence of a mass, deep invasion, or prominent sclerosis. With the advent of widespread molecular genetic testing, it would seem that LLLs should be polyclonal helping make the correct diagnosis. However, we have found cases with morphologic and immunophenotypic features of LLLs and evidence of clonal rearrangement of the immunoglobulin heavy chain (IGH) gene, potentially leading to misdiagnosis. We examined the clinicopathologic features and outcome of 12 patients with LLL (9 in the cervix and 3 in the endometrium). The patients ranged in age from 18 to 54 (median 37) years and came to medical attention because of squamous dysplasia (8 patients), vaginal bleeding (3), or adnexal mass (1). One patient had an endocervical polyp, but otherwise none had a discrete mass. The specimens contained a dense, polymorphous inflammatory infiltrate, commonly associated with mucosal erosion. Immunohistochemical studies showed a mixture of B and T cells without immunoglobulin light chain restriction. Four cases (all cervical) had a clonal IGH gene rearrangement by PCR. There was no evidence of lymphoma on staging or on follow-up in any patient, including the 4 patients with clonal IGH rearrangement, after a mean follow-up of 3.5 years (range: 4 mo to 13 y). In summary, we describe 12 patients with LLL of the lower female genital tract. Four of the 9 cases (44%) analyzed by PCR had a clonal IGH gene rearrangement. The clinical and pathologic features of these cases suggest that a clonal IGH rearrangement in this setting does not warrant a diagnosis of lymphoma. Careful correlation of clinical, histologic, immunophenotypic, and genetic features is required to avoid misdiagnosis and inappropriate treatment. Routine microscopic findings and detailed clinical information remain paramount in establishing the correct diagnosis.

Application of Immunohistochemistry in the Diagnosis of Non-Hodgkin and Hodgkin Lymphoma

Context.—Beginning with the immunologic classifications of Lukes and Collins and Kiel and culminating in the Revised European-American Lymphoma and World Health Organization classifications, the diagnosis of lymphoid tumors relies heavily on the determination of cell lineage, maturation, and function, based on antigen expression in addition to morphology and clinical features. Technologic advances in immunology, antibody production, genetic analysis, cloning, and the identification of new genes and proteins by microarray and proteomics have provided pathologists with many antibodies to use in routine diagnosis.

Objective.—To provide guidance to the practicing pathologist in the appropriate selection of an antibody panel for the diagnosis of lymphoma based on morphology and relevant clinical data and to avoid pitfalls in the interpretation of immunohistochemical data. Attention is given to some of the newer antibodies, particularly against transcription factors, that are diagnostically and prognostically useful.

Data Sources.—The information presented in this article is based on review of the literature using the OVID database (Ovid MEDLINE 1950 to present with daily update) and 20 years of experience in diagnostic hematopathology.

Conclusions.—Immunophenotyping is required for the diagnosis and classification of lymphoid malignancies. Many paraffin-reactive antibodies are available to the pathologist but most are not specific. To avoid diagnostic pitfalls, interpretation of marker studies must be based on a panel and knowledge of a particular antigen's expression in normal, reactive, and neoplastic conditions.

Site-specific morphologic differences in extranodal marginal zone B-cell lymphomas

CONTEXT

Lymphoepithelial lesions (LELs) are a useful diagnostic feature of extranodal marginal zone B-cell lymphoma (EMZL); however, there is scant literature comparing their frequency and morphology at various sites.

OBJECTIVE

To evaluate any diagnostically useful, site-specific, morphologic patterns in EMZLs.

DESIGN

In this retrospective review, we evaluated 136 EMZLs from different sites for LEL pattern and other pathologic differences, including CD43 coexpression and plasma cell component features.

RESULTS

Prominent and destructive LELs were most common in salivary and thyroid gland cases, and LELs were rare to absent in breast, skin, and ocular adnexa cases. An LEL pattern with lymphocytes "stuffing" glandular lumina was seen in lung, thyroid, and salivary gland cases. Monoclonal plasma cells were most common in breast, upper aerodigestive tract, skin, and salivary gland cases. CD43 coexpression was seen in 36% of cases, most commonly in salivary gland, stomach, and upper aerodigestive tract.

CONCLUSIONS

The relative importance of LEL pattern, CD43 coexpression, and clonal plasma cell component in EMZLs is site-dependent, and the differences may aid in the diagnosis of EMZLs at different anatomic sites.

Primary salivary gland lymphoma among Japanese: A clinicopathological study of 30 cases

To clarify the clinicopathological findings of primary salivary gland lymphoma as defined by the World Health Organization (WHO) classification, 30 Japanese patients with this disease were studied. The male to female ratio was 1:1.7 and median patient age was 57 years. The parotid gland (n = 22) was involved most frequently, followed by the submandibular gland (n = 5) and minor salivary gland (n = 3). Twenty-four (80%) cases demonstrated Stage IE, whereas only six (20%) had Stage IIE-1. None of the 30 cases had "B" symptoms or a poor performance status. The 5-year overall survival of 31 cases was 96% and 5-year failure-free survival was 77%. Histologically, 15 cases were mucosa-associated lymphoid tissue (MALT) lymphoma, seven were follicular lymphoma (FL), and six were diffuse large B-cell lymphoma (DLBCL) + MALT lymphoma and only two were DLBCL without a MALT lymphoma component. MALT lymphoma is the most frequent type of primary salivary gland lymphoma. However, FL comprised 20% of primary salivary gland lymphoma. The majority of the primary salivary gland DLBCL appear to arise from MALT type lymphoma. When appropriate therapy for histologic subtype is used, outcome of the primary salivary gland B-cell lymphoma appears excellent whether histologically indolent or aggressive.

Extranodal Marginal Zone B-cell Lymphomas of the Ocular Adnexa

Extranodal marginal zone B-cell lymphomas of MALT type (MALT lymphomas) show site-dependent variations in their morphologic, phenotypic, and/or cytogenetic findings. This report describes a comprehensive analysis of 34 ocular adnexa MALT lymphomas, including interphase fluorescence in situ hybridization for MALT lymphoma-associated cytogenetic abnormalities and polymerase chain reaction for Chlamydia psittaci, which has recently been suggested to be associated with ocular adnexa lymphomas. A typical morphologic pattern was identified in 79% of cases, while overtly monocytoid cytology (12%), predominantly plasmacytic features (9%), and lymphoepithelial lesions (3%) were uncommon. Aberrant CD43 or CD5 expression was also uncommon (12% and 3%, respectively). Plasmacytic differentiation (41%) was associated with stage IV disease (P=0.036) and gains of chromosomes 3 and/or 18q (P=0.021) (79%). +3 was more frequent in the orbit than in lacrimal gland or conjunctiva (P=0.005). Each of 31 cases was negative for MALT1 translocations. IGH translocations were identified in 3 cases (10%), although the translocation partner gene could not be identified. Polymerase chain reaction assays targeting species-specific regions within the C. psittaci omp1 and omp2 genes were negative in each of 30 cases. This study identifies the characteristic morphologic, phenotypic, and cytogenetic findings in ocular adnexa MALT lymphoma, including a subset differing from those arising at other anatomic sites. The frequent presence of +3 and/or +18q suggests that these abnormalities may contribute to lymphomagenesis. The lack of C. psittaci in this series, in contrast to some prior reports, indicates that there may also be geographic heterogeneity in the pathogenesis of ocular adnexa MALT lymphoma.

MALT1, BCL10 and FOXP1 in salivary gland mucosa-associated lymphoid tissue lymphomas

In view of the certain anatomic site-dependent frequency of chromosomal translocations involved in extranodal marginal zone B cell lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) pathogenesis, 17 salivary gland MALT lymphoma cases were analyzed for MALT1 and FOXP1 translocations. B cell CLL/lymphoma 10 (BCL10) and forkhead box PA (FOXP1) protein expression were studied by immunohistochemistry and translocations identified using fluorescence in situ hybridization (FISH)-specific probes FOXP1, t(11;18)(q21;q21)/API2-MALT1 and t(14;18)(q32;q21)/IgH-MALT1. None of the 11 analyzed cases showed FOXP1 rearrangement or amplification. The t(11;18) was present in five of 13 cases and the t(14;18) in three of 13 cases. MALT1 translocations were mostly mutually exclusive except in a single case. FOXP1 protein expression showed differences in the proportion of tumor cells with nuclear expression but not in their intensity, with the exception of one case where very intense nuclear staining was noted. BCL10 nuclear expression was present in four of 17 cases, two of which lacked t(11;18). Our results suggest that MALT1-specific translocations and FOXP1 rearrangements are not commonly involved in pathogenesis. A case with strong FOXP1 protein expression indicates the possibility that the upregulation of FOXP1 expression is significant in a small subset of salivary gland MALT lymphomas. Also a single case in which both MALT1 translocations were present indicates that these are not always mutually exclusive.

Mucosa-associated lymphoid tissue (MALT) lymphoma: a practical guide for pathologists

Extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) is the third most common non-Hodgkin lymphoma subtype, accounting for around 6-8% of all non-Hodgkin lymphomas in the Western hemisphere. Although MALT lymphomas are clinically indolent, the disease is typically chronic, requiring long-term clinical surveillance and, often, repeated biopsies. Pathologists thus play a central role in the diagnosis and management of these patients. The optimal diagnosis and management of a MALT lymphoma requires careful integration of morphological, immunohistochemical and molecular information, together with close cooperation with the clinician treating the patient. This review discusses recent developments in the molecular pathogenesis of MALT lymphoma and provides strategies for integrating this information into daily pathological practice.

Update on extranodal lymphomas. Conclusions of the Workshop held by the EAHP and the SH in Thessaloniki, Greece

Classification and proper treatment of extranodal lymphoma is hindered by the diversity of lymphoma types and the relative rarity of many of these tumour types. In order to review controversial issues in extranodal lymphoma diagnosis, a joint Workshop of the European Haematopathology Association (EAHP) and the Society for Hematopathology (SH) was held, where 99 selected cases were reviewed and discussed. This Workshop summary is focused on the most controversial aspect of cutaneous B-cell lymphoma, other extranodal B-cell lymphomas, plasmablastic lymphoma and anaplastic large-cell lymphoma in extranodal sites, and makes practical recommendations about diagnosis and therapeutic approaches.

Extranodal lymphomas of the head and neck

Malignant lymphomas represent approximately 5% of all malignant neoplasms of the head and neck and may involve nodal or extranodal sites. Nodal head and neck lymphomas are similar to other nodal sites and are not further reviewed here. The head and neck region is the second most frequent anatomical site of extranodal lymphomas (after the gastrointestinal tract). Most are non-Hodgkin's lymphomas of B-cell lineage, and overall diffuse large B-cell lymphoma is the most common type. Hodgkin's lymphoma rarely occurs in extranodal sites. Other hematologic neoplasms that commonly involve extranodal sites of the head and neck are also discussed. In this review, we begin by discussing lymphomas involving the head and neck according to anatomical site. Then we discuss specifically the pathological findings of extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue, plasmablastic lymphoma, extramedullary plasmacytoma, and extranodal natural killer/T-cell lymphoma of nasal type.

Instability of clonality in gastric lymphoid infiltrates: a study with emphasis on serial biopsies

The evolution of low-grade B-cell mucosa-associated lymphoid-tissue (MALT) lymphoma of the stomach is a multistage process, reflected in the histologic continuum from Helicobacter pylori-chronic gastritis, to low-grade and high-grade lymphoma. Interestingly, in daily gastric biopsy sign-out, the authors observed that some biopsies showed monoclonality on polymerase chain reaction (PCR) even though there were no definite histologic features of malignancy and vice versa. To address the question, the authors studied the endoscopic gastric biopsies at first presentation of 46 patients to examine any clonality differences among various histologic patterns within the spectrum of MALT lymphoma evolution. The gastric biopsies were reviewed histologically and graded according to the Wotherspoon-Isaacson histologic scoring system from grade 0 (normal) to grade 5 (MALT lymphoma). The clonality of cases in each grade was determined by performing nested PCR for immunoglobulin heavy chain (IgH) gene rearrangement using FR2/JH and FR3/JH primer sets. The monoclonality rates among different grades were as follows: grade 2, 6.3% (1 of 16); grade 3, 27.3% (3 of 11); grade 4, 83.3% (5 of 6); grade 5, 69.2% (9 of 13). Statistically significant difference of monoclonality rate is demonstrated in histologic grade 4 versus grades 2 and 3, and grade 5 versus grade 2 (P < 0.05, Fisher exact test). The authors went on to examine the progress of disease by following up the clinical status, histologic changes, and clonality fluctuation of these cases. Four of the 8 patients with monoclonality on PCR, but no definite lymphoma at first presentation later progressed to frank MALT lymphoma. Our study shows that, during the progression to MALT lymphoma, there is an instability of clonality. Clonality can fluctuate between polyclonality, oligoclonality, and monoclonality, none of which defines an irreversible stage for progression to MALT lymphoma. Monoclonality is a risk factor for development of MALT lymphoma. Those cases with dense gastric mucosal lymphoid infiltrate (without definite MALT lymphoma) and monoclonality on PCR need to be closely monitored and Helicobacter infection promptly treated if present. In combination with clinicohistologic examination, PCR can serve as a complementary tool in arriving at a definite diagnosis of MALT lymphoma in cases with borderline histologic features.

Clonal B cell populations in a minority of patients with Hashimoto's thyroiditis

BACKGROUND

Hashimoto's thyroiditis (HT) is a risk factor for thyroid lymphoma, and clonal B cell populations in HT support this link. The literature on B cell clonality in HT is controversial.

AIMS

To identify clonal B cell populations in HT and to assess their usefulness in differentiating HT from mucosa associated lymphoid tissue (MALT) lymphoma and predicting future development of lymphoma.

METHODS

DNA from formalin fixed, paraffin wax embedded blocks of thyroid specimens from 10 patients with HT and two thyroid MALT lymphomas was analysed for B cell clonality by seminested polymerase chain reaction (PCR) using FRIII/LJH and FRIII/VLJH primers to amplify the IgH gene VDJ region. In one case, PCR products were sequenced. Immunohistochemistry was performed by labelled streptavidin-biotin technique using antibodies to: CD45, CD45RO, CD3, CD20, and cytokeratin.

RESULTS

The histopathological and clinical findings were characteristic of HT. Clonal bands were seen in three and a polyclonal smear pattern was seen in seven cases. The clonal bands in HT were associated with a background smear, and could not be reproduced from other blocks from the same case or from deeper sections of the same block. The clonal bands in thyroid lymphomas were not associated with a background smear and were reproducible. None of the patients with clonal B cells has developed malignant lymphoma during a follow up of 10-13 years.

CONCLUSIONS

B cell clonal bands in HT have different features from those in lymphoma (non-pure and non-reproducible) and do not predict future development of lymphoma.

The role of molecular studies in lymphoma diagnosis: a review

Lymphoma classification is based on a multiparametric approach to diagnosis, in which clinical features, morphology, immunophenotype, karyotype and molecular characteristics are important to varying degrees. While in most cases, a diagnosis can be confidently established on the basis of morphology and immunophenotype alone, a small proportion of diagnostically difficult cases will rely on molecular studies to enable a definitive diagnosis. This review discusses the various molecular techniques available including Southern blotting (SB), polymerase chain reaction (PCR), fluorescence in situ hybridisation (FISH)--including multicolour-FISH/spectral karyotyping and comparative genomic hybridisation--and also gene expression profiling using cDNA microarray technology. Emphasis is given to the analysis of antigen receptor gene rearrangements and chromosomal translocations as they relate to lymphoma diagnosis and also in the setting of minimal residual disease (MRD) detection and monitoring. Laboratories performing these tests need to have expertise in these areas of testing, and there is a need for greater standardisation of molecular tests. It is important to know the sensitivity and specificity of each test as well as its limitations and the pitfalls in the interpretation of results. Above all, results of molecular testing should never be considered in isolation, and must always be interpreted in the context of clinical and other laboratory data.

Primary B-cell lymphoma and lymphoma-like lesions of the uterine cervix

We present three patients with atypical lymphoid cells on cervical smear screening, with diffuse large-cell B-cell lymphoma diagnosed by morphology on cervical biopsy. One patient with extensive pelvic disease was treated with chemotherapy and radiotherapy and remained in remission 8 years later. Two patients with presumed stage 1E lesions showed spontaneous regression on repeat cervical biopsy, despite light chain restriction and clonal immunoglobulin gene rearrangement. They are without recurrent malignancy 1 and 5 years after their initial diagnosis. The presence of malignant looking lymphoid cells on cervical smear should be investigated by repeated colposcopic biopsies. The reason for the highly skewed atypical B-cell lymphoproliferation in lymphoma-like lesions of the cervix is unknown. With early stage, nonbulky cervical lymphoma in an otherwise healthy patient, a cone biopsy is advised. A number of these lesions may regress even when clonal populations are detected.

Salivary gland expression of transforming growth factor beta isoforms in Sjogren's syndrome and benign lymphoepithelial lesions

AIM

Transforming growth factor beta (TGF-beta) is involved in the control of autoimmune reactions, cell proliferation, and the accumulation of lymphocytes within organs. The aim of this study was to determine the expression of TGF-beta in salivary glands from patients with primary Sjogren's syndrome (SS) and benign lymphoepithelial lesions (BLEL) with emphasis on ductal epithelium.

METHODS

Immunoperoxidase staining for TGF-beta isoforms and Ki67 antigen was performed on formalin fixed sections of labial glands from patients with primary SS (n = 15) and controls (n = 5) and parotid glands reported as BLEL (n = 5) or normal (n = 5). Ductal expression of TGF-beta was quantified by absorbance measurements using image analysis. The specificity of staining was confirmed by peptide blocking studies.

RESULTS

All TGF-beta isoforms were detected within the cytoplasm of most lymphocytes, endothelial cells, and ducts in all specimens. Acinar expression was variable and weaker than that seen in ducts. Absorbance measurements revealed that the expression of all isoforms was greater in ducts within primary SS glands than in control glands. Ductal expression in control parotid glands was greater than that seen in BLEL glands, irrespective of the presence of adjacent lymphoid infiltrates. Comparisons between control specimens showed that ductal expression of all isoforms was highest in parotid glands, whereas no differences were detected between primary SS and BLEL glands. Ki67 positive lymphocytes and duct cells were mainly restricted to pathological specimens, with BLEL glands containing larger populations of positive cells than primary SS glands.

CONCLUSION

These results demonstrate complex and variable changes in ductal expression of TGF-beta in primary SS and BLEL, which may be important in the control of lymphoid infiltration and the proliferation of lymphocytes and ductal epithelium.

Rearrangement of immunoglobulin heavy and light chains and VH family in thyroid and salivary gland lymphomas

It is often difficult to differentiate extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) from non-neoplastic inflammatory conditions. Demonstration of clonal lymphoid proliferation by molecular procedures is important for accurate diagnosis. We examined the clonal population of B-cell lymphomas in nine cases of thyroid and two cases of salivary gland B-cell lymphoma using semi-nested polymerase chain reaction (PCR)-based assay for IgH gene arrangement and reverse transcription (RT)-PCR single-strand conformation polymorphism (SSCP) for the detection of IgL gene rearrangement. Clonality was evident in nine out of 11 cases of B-cell lymphomas examined by PCR, and in six of eight cases by RT-PCR SSCP. In addition, analysis of VH families was performed in eight cases. Although VH3 family was frequently used, each case demonstrated the VH4, VH5 or VH6 family. It is possible that the normal counterpart of thyroid or salivary gland lymphoma might be different from peripheral blood B lymphocytes, which usually use VH3 family. Our results indicate that although no clonality was noted in one case by both PCR and SSCP, these molecular methods are useful as supplementary diagnostic tests for both thyroid and salivary gland lymphomas.

Current issues in Sjögren's syndrome

Sjögren's syndrome is a chronic autoimmune and rheumatic disorder with prominent sicca complaints from the mucous membranes because of lack of proper exocrine secretions. There is no straightforward and simple diagnostic test for Sjögren's syndrome, although several classification criteria have been designed including several oral diagnostic tests. A new set of classification criteria in a joint effort by research groups in Europe and USA has recently been presented. A large number of autoantibodies have been reported in Sjögren's syndrome where, in some cases, the antibodies are correlated with the extent and severity of disease. The finding of serum autoantibodies directed against the muscarinic M3 receptor is an important advance in understanding the pathogenesis of not only the impaired glandular function but also associated features of autonomic dysfunction in some patients. The treatment of primary Sjögren's syndrome is still mainly symptomatic.

Lymphoid lesions of the head and neck: a model of lymphocyte homing and lymphomagenesis

Lymphoid lesions of the head and neck mainly affect the nasopharynx, nasal and paranasal sinuses, and salivary glands. These three compartments each are affected by a different spectrum of lymphoid malignancies and can serve as model for mechanisms of lymphomagenesis. The type of lymphoma seen reflects the underlying biology and function of the particular site involved. The nasopharynx and Waldeyer's ring are functionally similar to the mucosal associated lymphoid tissue (MALT) of the gastrointestinal tract and are most commonly affected by B-cell lymphomas, with mantle cell lymphoma being a relatively frequent subtype. The most prevalent lymphoid lesion of the salivary gland is lymphoepithelial sialadenitis, associated with Sjögren's syndrome. Lymphoepithelial sialadenitis is a condition in which MALT is acquired in a site not normally containing lymphoid tissue. Patients with Sjögren's syndrome are at increased risk to develop B-cell lymphomas, most commonly MALT lymphomas. The nasal and paranasal sinuses are the prototypical site for the development of extranodal natural killer (NK) /T-cell lymphoma, nasal type. This condition must be distinguished from other conditions causing the clinical picture of lethal midline granuloma, including Wegener's granulomatosis and infectious disorders. Lymphomatoid granulomatosis is common in the lung but is rarely seen in the midline facial structures.

Benign lymphoepithelial lesion associated with squamous cell carcinoma of the skin: an immunohistochemical and molecular genetic study

BACKGROUND

Benign lymphoepithelial lesions (BLEL) are usually found in salivary glands in autoimmune disorders. Some LEL are recognized to already be, or may progress to become, lymphomas. Skin lesions similar to LEL have been described in lymphomas, and are caused by neoplastic lymphocytes which infiltrate adnexal structures. To date, BLEL have not widely been recognized in the skin.

METHODS

We describe skin lesions similar to BLELs, at the periphery of squamous cell carcinomas (SCC) in 8 healthy patients, in one of whom the lesion recurred. Immunocharacterization of both epithelial and lymphocytic components and molecular genetic investigation was performed. Polymerase chain reaction (PCR) analysis was done to detect IgH chain gene, and T-cell receptor beta and gamma gene rearrangements. Association with Epstein-Barr virus (EBV) was also tested by in situ hybridization (ISH) for EBV-encoded RNAs (EBERs).

RESULTS

Epithelial cells showed the immunophenotype of eccrine sweat gland ducts. Infiltrating lymphocytes expressed overwhelming B antigens and CD5. Neither clonal B and/or T proliferations nor EBERs signals were demonstrable.

CONCLUSIONS

We observed skin lesions similar to BLELs, showing modifications of sweat gland duct and CD5+, B lymphocytic expansion. In our cases there were no associated autoimmune disorders; the local immunoresponse to SCC might have caused BLEL.

Primary low-grade MALT lymphoma of the gallbladder

We report a case of primary low-grade B-cell lymphoma of the mucosa-associated lymphoid tissue (low-grade MALT lymphoma) in the gallbladder. A 58-year-old woman suspected of gallbladder carcinoma underwent laparoscopic cholecystectomy. Microscopic examination of the gallbladder demonstrated lymphoid cell infiltration forming lymphoid follicles with hyperplastic secondary follicles. The surrounding monocytoid B cells and centrocyte-like cells selectively infiltrated the crypt epithelium forming lympho-epithelial lesions. Plasma cells were also noted beneath the mucosal epithelium. Bile culture revealed the Gram-negative bacilli Enterococcus faecalis and Morganella morganii. Immunoglobulin heavy chain gene rearrangement was confirmed using polymerase chain reaction (PCR) and oligoclonal lymphoid proliferations was detected. Because autoimmune diseases, or chronic inflammatory disorders, seem to correlate with the occurrence of MALT lymphoma, Gram-negative bacterial infection could also be considered as a prodrome of MALT lymphoma of the gallbladder.

Marginal zone B-cell lymphoma of the salivary gland arising in chronic sclerosing sialadenitis (Küttner tumor)

We report a case of extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) type of the salivary gland arising in a background of chronic sclerosing sialadenitis. Chronic sclerosing sialadenitis is a common fibrosing chronic inflammatory lesion of the submandibular gland, which is thought to be the result of sialolithiasis, and is not associated with a systemic autoimmune disease. Salivary MALT lymphomas are typically associated with lymphoepithelial sialadenitis (LESA) in a patient with or without Sjögren's syndrome. Our case of salivary MALT lymphoma was neither preceded by Sjögren's syndrome nor accompanied by LESA. This case suggests that chronic inflammatory processes other than Sjögren's syndrome may provide a substrate for the development of MALT lymphoma.

Preliminary classification of nonmalignant B cell proliferation in Sjögren's syndrome: perspectives on pathobiology and treatment based on an integrated clinico-pathologic and molecular study approach

A classification of nonmalignant lymphoproliferation in Sjögren's syndrome is presented, based on the results of international meetings regarding Sjögren's syndrome-associated lymphomagenesis and on our results of a clinico-pathologic and molecular study and long-term follow-up in well-characterized patients. Sjögren's syndrome pathobiology has similarities to hepatitis C virus-related B-cell lymphoproliferation. Antigen stimulation with the preferential expansion of rheumatoid factor-positive clones and specific immunoglobulin gene expression and recombination represent key biologic events in lymphoproliferation. This classification is based on the coupling of molecular and histological studies and may result in more selective treatment approaches.

Chemokines and cell trafficking in Sjögren's syndrome

Sjögren's syndrome is a chronic inflammatory condition affecting exocrine glands, manifested clinically as dry eyes and dry mouth. It arises secondary to systemic immune-mediated diseases such as rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), scleroderma or 'primary' Sjögren's syndrome. Histologically it is characterized by peri-ductal aggregates of CD4 T lymphocytes, the frequent occurrence of ectopic germinal centres and, in some patients, B-cell infiltration of ductal epithelium (myoepithelial sialadenitis). This latter lesion is the precursor for the development of low grade (MALT) B-cell lymphoma. The identification over recent years of chemokines and their receptors enables us to address the specific processes involved in the migration of inflammatory cells into exocrine glands, the development of their secondary structures and patterns of retention within the glands and potentially the subsequent transformation of B cells into mucosa associated lymphoid tissue (MALT) lymphoma.

Molecular analysis of mucosa-associated lymphoid tissue (MALT) lymphoma of ocular adnexa

Lymphomas of mucosa-associated lymphoid tissue (MALT) are a distinct subgroup of extranodal B-cell non-Hodgkin's lymphomas. Most studies have failed to demonstrate the clonal rearrangement of BCL-1, BCL-2 or c-MYC genes for MALT lymphomas. Further, alteration of the p53 gene is rarely demonstrated in low-grade MALT lymphomas, but can be detected in high-grade disease. Lymphomas of the ocular adnexa represent approximately eight percent of all extranodal lymphomas, most of which are MALT lymphomas, but few studies had explored the alterations of BCL-1, BCL-2, c-MYC and p53 genes specifically for ocular MALT lymphomas. We investigated the changes to BCL-1, BCL-2, c-MYC and p53 genes in these lymphomas for Taiwanese patients. Clonal rearrangement for immunoglobulin heavy-chain (IgH), BCL-1, BCL-2, c-MYC and p53 genes was examined for 16 cases of ocular MALT lymphoma. Restriction-length polymorphism and polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) of the DNA, corresponding to exons 5 through 9, followed by DNA sequencing, were utilized to analyze the possible mutations of the p53 gene for these tumors. Thirteen of the cases revealed rearranged IgH genes using Southern blotting or PCR. No rearrangement of BCL-1, BCL-2, c-MYC or p53 genes was discovered, with point mutation of the p53 gene in one case. As for other types of MALT lymphomas, BCL-1, BCL-2 and c-MYC genes are not implicated in the pathogenesis of the ocular sub-group. Although alteration of the p53 gene is rare for low-grade ocular MALT lymphoma, its role in disease progression merits further research.

Pathological features of lymphoid proliferations of the salivary glands: lymphoepithelial sialadenitis versus low-grade B-cell lymphoma of the malt type

Lymphoid proliferations of the salivary glands can be either reactive or neoplastic. Reactive lesions include the lymphoepithelial sialadenitis (LESA; also known as myoepithelial sialadenitis [MESA]) of Sjogren's syndrome. Lymphomas of the salivary glands are predominantly B-cell type and include extranodal marginal zone B-cell lymphoma of the mucosa-associated lymphoid tissue (MALT) type. The spectrum of histopathologic features of LESA/MESA includes 1) "fully benign lymphoid infiltrate," with or without an associated lymphoid follicular structure, without immunoglobulin (Ig) light chain restriction in B-cells, and without any features of aggressive behavior, and 2) "lymphoproliferative lesions," with or without areas of Ig light chain restriction in B-cells, with the usual presence of centrocyte-like cells. A more or less pronounced lymphoepithelial aggressiveness may be present without definite evidence of malignancy. B-cell clones are detected in over 50% of cases of LESA/MESA by molecular genetic methods, but this does not correlate with morphological or clinical evidence of overt lymphoma. On the other hand, "marginal zone B-cell lymphoma of the MALT type" of the salivary glands produces a dense lymphoid infiltrate diffusely involving the gland, with obliteration of acini. The centrocyte-like cells form broad "halos" around the epithelial cell nests and broad strands between lymphoepithelial lesions, often linking together several lymphoepithelial lesions. Further, lymphoma cells express monotypic surface Ig, and in the majority of the cases, the plasma cells are also monoclonal. In conclusion, the diagnosis of LESA/MESA versus marginal zone B-cell lymphoma of the MALT type still relies on the evaluation of morphological features. It seems that molecular genetic analysis has little or no practical role in the clinical diagnosis of salivary gland lymphoma in a setting of LESA/MESA and Sjögren's syndrome.

Lack of mutations of BCL6 and BCL10 genes in mucosa-associated lymphoid tissue lymphomas of the orbital adnexa

Knowledge regarding the molecular pathogenesis and progression of mucosa-associated lymphoid tissue (MALT) lymphomas of ocular adnexa is limited. Eleven cases of ocular MALT lymphoma were analyzed by clonal rearrangement of antigen receptor genes using Southern blot hybridization. Polymerase chain reaction-single stranded conformational polymorphism analysis and DNA sequencing was utilized to analyze the mutations of BCL6 and BCL10 genes. Clonal rearrangement of immunoglobulin heavy genes was found in all 11 patients. No point mutation was found in BCL6 or BCL10 genes in any of the samples analyzed. We suggest that mutations of BCL6 and BCL10 genes are rare in low-grade MALT lymphoma of ocular adnexa and are unlikely to be involved in the pathogenesis of the disease. But the role of alterations of both BCL6 and BCL10 genes in the disease progression of low-grade MALT lymphoma require additional study.

Nodular amyloidoma and primary pulmonary lymphoma with amyloid production: a differential diagnostic problem

Nodular amyloidomas (NA) of the lung are non-neoplastic inflammatory nodules containing eosinophilic amyloid deposits and a lymphoplasmacytic infiltrate. In some instances, the extensive amyloid deposits may obscure an underlying lymphoproliferative disorder. The histologic and immunohistologic features that discriminate these two differential diagnostic possibilities were studied in this series of six cases of NA and five cases of primary low-grade malignant lymphomas of lung with secondary amyloid deposits (ML). Two of lymphoma cases showed histopathologic and immunophenotypic features of B-cell chronic lymphocytic leukemia/small lymphocytic lymphoma (B-cell CLL/SLL), and three cases were low-grade B-cell lymphoma derived from mucosa associated lymphoid tissue (MALT lymphoma). Key discriminating morphologic features between NA and ML included lymphatic tracking of the cellular infiltrate (3/5 ML; 1/6 NA), pleural infiltration (3/5 ML; 0/6 NA), sheet-like masses of plasma cells (5/5 ML; 0/6 NA) and reactive follicles (4/5 ML; 1/6 NA). Lesional circumscription, vascular and bronchial destruction, lymphoepithelial lesions, and granulomas were not helpful discriminators. Immunohistochemical features indicating a dominant CD20+, CD79a+ B-cell population (5/5 ML; 0/6 NA), light chain restriction (4/5 ML; 0/6 NA), and aberrant antigen expression of CD20/CD43 (2/5 ML; 0/6 NA) were helpful. Amyloid tumors with a reactive lymphoplasmacytic infiltrate can be separated from low-grade malignant lymphomas utilizing both histologic and immunohistochemical features.