Kuttner tumor (chronic sclerosing sialadenitis) of the submandibular gland: an underrecognized entity

Chronic Sclerosing Sialadenitis of the Submandibular Gland and its Histopathological Spectrum in the IgG4-Related Disease: a Series of 17 Cases

PURPOSE

This study aimed to characterize the histopathological immunohistochemical features of chronic sclerosing sialadenitis, emphasizing the IgG4-related disease.

METHODS

Seventeen cases of chronic sclerosing sialoadenitis were examined for histopathological aspects, (inflammation, fibrosis, glandular parenchyma, and lymphoid follicles) and immunohistochemistry (BCL2, CD3, CD20, CD34, CD163, p63, cyclin D1, mast cell, SMA, S100A4, IgG, and IgG4) which were scored. IgG4-related disease features were investigated. Demographic and clinical data were also collected.

RESULTS

Males predominated (10:7), with an average lesion size of 3.9 cm. Common histopathological findings included reduced acinar parenchyma, lymphoid follicle formation, and ductular proliferation. CD3-positive T lymphocytes and CD34- and SMA-positive stromal fibroblasts were abundant. Nine cases (53%) showed sialoliths and three cases met the criteria for IgG4-related disease.

CONCLUSION

CSS of the submandibular gland represents a reactive pattern rather than IgG4-RD as only 3 cases seemed to be related to IgG4-RD. The immunohistochemical profile revealed an abundant population of CD3-positive T lymphocytes, as opposed to regulatory proteins such as cyclin D1, demonstrating that populations of CD34- and SMA-positive stromal fibroblasts contribute to the fibrosis characteristic of CSS. In addition, our results provide a comprehensive insight into the study of CSS and its relationship with IgG4-RD.

Immunological characteristics of IgG4-related Kuttner tumors

Immunoglobulin G4-related disease (IgG4-RD) has recently been well recognized and Kuttner tumor is known to be a chronic sclerosing sialadenitis, representing the focal manifestation of IgG4-RD, in the submandibular gland (SMG). This study is to evaluate the immunologic features of IgG4-related Kuttner tumor in the SMG. We retrospectively chose 13 patients who were confirmed as having Kuttner tumor by surgical biopsy between May 2012 and January 2019. The fine-needle aspiration cytology, serum antibody levels (anti-Ro antibodies, anti-La antibodies), IgG serum levels (total IgG and IgG4), and immunohistochemical findings for IgG and IgG4-positive plasma cells were reviewed. The cytologic results found that 7 of the 9 cases were reported as chronic sialoadenitis, and the other 3 as benign lymphoproliferative lesion. The serum levels of autoantibodies, Sjögren-syndrome-related antigen A/Ro-Ab and Sjögren-syndrome-related antigen A/Ro-La, showed all normal values of serum level. The serum level of IgG was increased in only 4 among the cases. However, the IgG4 levels were significantly increased in 11 among the cases. In all the patients who received resection of SMG, immunohistochemical findings showed all positive for IgG4-RD, with elevated numbers of IgG and IgG4-positive plasma cells. The evaluation of IgG4 serum level should be very informative for the diagnosis of this tumor before surgery. Fine-needle aspiration cytology with ultrasound guidance are not conclusive in this study. The immunological study including IgG4 serum level should be required for proper diagnosis and treatment, with clinical features of the Kuttner tumor. The level of evidence was IV.

Not All Küttner Tumors Are IgG4-Related Disease (IgG4-RD)

Küttner tumor is an uncommon cause of salivary gland enlargement that most frequently affects the submandibular gland. More recently it has been considered a manifestation of IgG4-related disease (IgG4-RD) and synonymous with chronic sclerosing sialadenitis (CSS). We present a series of cases to emphasize this clinical entity as a disease pattern and presentation that is separate from IgG4-RD. Retrospective case series of 3 patients with unilateral salivary gland enlargement, or "Küttner tumor," histologically classified as "chronic sclerosing sialadenitis," The clinical history, radiology reports, laboratory studies, and pathology slides were reviewed for each case. Radiology showed discrete unilateral mass-like lesions in all three cases. Immunohistochemistry showed reduced tissue IgG4-positive plasma cells in two cases and increased numbers in one case, but insufficient to diagnose IgG4-RD. Storiform fibrosis was not seen in all cases and did not coincide with increased IgG4-positive plasma cells. A systemic workup, including serum IgG4 levels in two cases, was normal. A brief review of the literature on the spectrum of salivary gland involvement by IgG4-RD is presented. Küttner tumor is not necessarily the same as chronic sclerosing sialadenitis and is not always associated with IgG4-related disease. This report includes the second documented case of Küttner tumor of the sublingual gland.

Recent advances in knowledge regarding the head and neck manifestations of IgG4-related disease

IgG4-related disease (IgG4-RD) is a chronic inflammatory disorder, characterized by elevated serum IgG4 levels as well as abundant infiltration of IgG4-positive plasmacytes and fibrosis in various organs, including the head and neck region. In particular, the salivary glands, orbit, and thyroid are common sites of disease involvement. IgG4-RD is diagnosed based on various clinical, serological, and histopathological findings, none of which are pathognomonic. Hence, various differential diagnoses, which exhibit elevated serum IgG4 levels and infiltration of IgG4-postive cells into tissues, need to be excluded, especially malignant diseases and mimicking disorders. Systemic corticosteroids are generally effective in inducing IgG4-RD remission; however, recurrent or refractory cases are common. In addition, although the pathogenic mechanisms of IgG4-RD remain unclear, an antigen-driven inflammatory condition is believed to be involved. Recent studies have indicated the important pathogenic role of B cell/T cell collaboration and innate immunity in this disease. Nevertheless, additional research and discussions are needed to resolve many remaining questions. In this review, we provide an overview of the recent insights on the history, clinical features, diagnosis, and treatment of IgG4-RD in the head and neck region. Furthermore, we have also addressed the pathogenesis of this disease.

Clinicopathology of Immunoglobulin G4–Related Chronic Sclerosing Sialadenitis

Objectives

To investigate the clinicopathologic characteristics of patients with immunoglobulin G4–related chronic sclerosing sialadenitis (IgG4-RCSS), a recently recognized disease.

Study Design

Case series with chart review and pathology study.

Settings

Tertiary care hospital.

Subjects and Methods

We evaluated chronic sialadenitis specimens obtained over 11 years using pathologic examination and IgG4 immunohistochemistry staining. The specimens were assigned a revised diagnosis of IgG4-RCSS or chronic sialadenitis not otherwise specified, and clinicopathologic data from each group were compared.

Results

Of the 84 patients, 21 were diagnosed with IgG4-RCSS and 63 with chronic sialadenitis not otherwise specified. IgG4-RCSS patients were older (68.2 ± 13.9 vs 54.2 ± 15.8 years, P = .001), predominantly male (85.7% vs 61.9%, P = .036), and more likely to present with painless swelling (75% vs 44.3%, P = .001) and bilateral involvement (52.4% vs 6.3%, P < .001). Ratio of IgG4-positive plasma cells to IgG-positive plasma cells in IgG4-RCSS tissues was 0.81 ± 0.14. The mean value of serum IgG4 in IgG4-RCSS patients was 918.8 mg/dL.

Conclusion

IgG4-RCSS is more common in older male patients and frequently presents with bilateral involvement. Informing head and neck surgeons of the clinical features of IgG4-RCSS and promoting a combined approach of clinical evaluation, imaging, and biopsy can improve the accuracy of preoperative diagnoses.

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.

Immunoglobulin G4 related chronic sclerosing sialadenitis

Background:

ENT surgeons may be the first specialists to encounter and diagnose patients with salivary gland disease. A new entity involving the salivary glands has recently been described of which ENT surgeons need to be aware: immunoglobulin G4 related chronic sclerosing sialadenitis.

Method:

A literature search of Medline, Embase and Cochrane Library databases was performed, using the search terms ‘IgG4’, ‘hyperIgG4 syndrome’ and ‘IgG4 related chronic sclerosing sialadenitis’.

Results:

Knowledge concerning immunoglobulin G4 related chronic sclerosing sialadenitis is rapidly increasing. This new entity is part of a fibro-inflammatory corticosteroid-responsive systemic disease (immunoglobulin G4 related disease) and has been described in almost every organ. Biopsy of the submandibular gland can be diagnostic. However, the diagnosis can easily be overlooked if: clinical suspicion is not high, one is unaware of the classical morphology and/or immunoglobulin G4 staining is not performed. This paper presents a summary of the current understanding of the disease and its management.

Conclusion:

ENT surgeons should be aware of this new disease entity. Patients with systemic disease should be managed under a multidisciplinary team, with input from clinicians who have an interest in such diseases (such as gastroenterologists and rheumatologists), and input from histopathologists and radiologists.

IgG4 plasma cell myeloma: new insights into the pathogenesis of IgG4-related disease

IgG4-related disease is a newly described systemic fibroinflammatory process, characterized by increase in IgG4-positive plasma cells. Its pathogenesis, including the role of IgG4, remains poorly understood. Plasma cell myeloma is typically associated with a large monoclonal serum spike, which is frequently of IgG isotype. We sought to identify and characterize a subset of IgG4-secreting myeloma, as it may provide a biological model of disease with high serum levels of IgG4. Six out of 158 bone marrow biopsies (4%) from patients with IgG myeloma expressed IgG4. Four patients were men and two were women, with a mean age of 64 (range 53-87) years. Imaging showed fullness of pancreatic head (1), small non-metabolic lymphadenopathy (1), and bone lytic lesions (6). Two patients developed necrotizing fasciitis. All had elevated serum M-protein (mean 2.4, range 0.5-4.2 g/dl), and none had definite signs or symptoms of IgG4-related disease. Four myelomas had plasmablastic morphology. Four had kappa and two had lambda light chain expression. Three cases expressed CD56. Two patients had a complex karyotype. In conclusion, the frequency of IgG4 myeloma correlates with the normal distribution of IgG4 isoform. The patients with IgG4 myeloma appear to have a high rate of plasmablastic morphology and could be predisposed to necrotizing fasciitis. Despite high serum levels of IgG4, none had evidence of IgG4-related disease. These findings suggest that the increased number of IgG4-positive plasma cells is not the primary etiologic agent in IgG4-related disease. Elevated serum levels of IgG4 is not sufficient to produce the typical disease presentation and should not be considered diagnostic of IgG4-related disease.

IgG4-related disease in the head and neck

Lymphoid infiltrates are relatively common in the ocular adnexa and the salivary glands. They are of a variety of types and include both reactive processes and lymphomas. Within the ocular adnexa in years past, lymphoid proliferations were classified as inflammatory pseudotumor, reactive lymphoid hyperplasia, atypical lymphoid hyperplasia, and lymphoma. With improvements in diagnostic techniques and with advances in lymphoma subclassification, it became clear that many of the dense lymphoid infiltrates, including cases classified as lymphoma and likely some classified as atypical lymphoid hyperplasia, represented low-grade B-cell lymphomas, the most common of which by far were extranodal marginal zone lymphomas of mucosa-associated lymphoid tissue (MALT) lymphomas. Ocular adnexal inflammatory pseudotumor, reactive lymphoid hyperplasia, and chronic sclerosing sialadenitis were recognized, but the focus in diagnosis had been on avoiding misdiagnosis as a neoplastic process and in planning appropriate therapy. Recently, it has become clear that many cases of these reactive processes fall into the spectrum of immunoglobulin G4 (IgG4)-related disease, offering new insight into the pathogenesis of inflammatory lesions occurring in the ocular adnexa and the salivary glands. The majority of entities previously classified as chronic sclerosing sialadenitis, Mikulicz disease, orbital pseudolymphoma, and eosinophilic angiocentric fibrosis are now considered a part of the IgG4-related disease spectrum. In this review, we discuss the histologic and immunohistochemical features of IgG4-related disease of the head and neck and provide guidance for distinguishing this disease from its many mimics.

IgG4-related sclerosing disease, an emerging entity: a review of a multi-system disease

Immunoglobulin G4-related systemic disease (IgG4-RSD) is a recently defined emerging entity characterized by a diffuse or mass forming inflammatory reaction rich in IgG4-positive plasma cells associated with fibrosclerosis and obliterative phlebitis. IgG4-RSD usually affects middle aged and elderly patients, with a male predominance. It is associated with an elevated serum titer of IgG4, which acts as a marker for this recently characterized entity. The prototype is IgG4-related sclerosing pancreatitis or autoimmune pancreatitis (AIP). Other common sites of involvement are the hepatobiliary tract, salivary gland, orbit, and lymph node, however practically any organ can be involved, including upper aerodigestive tract, lung, aorta, mediastinum, retroperitoneum, soft tissue, skin, central nervous system, breast, kidney, and prostate. Fever or constitutional symptoms usually do not comprise part of the clinical picture. Laboratory findings detected include raised serum globulin, IgG and IgG4. An association with autoantibody detection (such as antinuclear antibodies and rheumatoid factor) is seen in some cases. Steroid therapy comprises the mainstay of treatment. Disease progression with involvement of multiple organ-sites may be encountered in a subset of cases and may follow a relapsing-remitting course. The principal histopathologic findings in several extranodal sites include lymphoplasmacytic infiltration, lymphoid follicle formation, sclerosis and obliterative phlebitis, along with atrophy and destruction of tissues. Immunohistochemical staining shows increased IgG4+ cells in the involved tissues (>50 per high-power field, with IgG4/IgG ratio >40%). IgG4-RSD may potentially be rarely associated with the development of lymphoma and carcinoma. However, the nature and pathogenesis of IgG4-RSD are yet to be fully elucidated and provide immense scope for further studies.

A novel concept of Mikulicz's disease as IgG4-related disease

Since Morgan's report in 1953, Mikulicz's disease (MD) has been considered part of primary Sjögren's syndrome (SS). However, MD has a unique presentation, including persistent swelling of the lacrimal and salivary glands, and is characterized by good responsiveness to glucocorticoids, leading to recovery of gland function. Recently, it has been revealed that MD patients show elevated serum immunoglobulin G4 (IgG4) levels and prominent infiltration of IgG4-positive plasmacytes. The complications of MD include autoimmune pancreatitis, retroperitoneal fibrosis, tubulointerstitial nephritis, autoimmune hypophysitis, and Riedel's thyroiditis, all of which show IgG4 involvement in their pathogenesis. Thus, MD is a systemic "IgG4-related disease." In addition, recent analyses have revealed that Küttner's tumor (KT), a chronic sclerosing sialadenitis that presents with asymmetrical firm swelling of the submandibular glands, is also associated with prominent infiltration of IgG4-positive plasmacytes. MD and KT differ from SS and are thought to be singular systemic IgG4-related plasmacytic diseases. Here we discuss the results of recent studies and provide an overview of MD as an IgG4-related disease.

Küttner's tumor of the sub-mandibular gland associated with fibrosclerosis and follicular hyperplasia of regional lymph nodes: a case report

Introduction

Küttner's tumor is characterized through histology by peri-ductal fibrosis, dense lymphocytic infiltration with lymphoid follicles, loss of acini, and occasional marked sclerosis of the salivary gland. On occasion, Küttner's tumor can be difficult to distinguish from malignant neoplasm.

Case presentation

A 58-year-old Japanese man was referred to our hospital with a three-month history of a painless swollen mass in the right sub-mandibular region. Histological findings revealed both lymphoid follicles with reactive germinal centers and variously sized lymphoid follicle-like nodules without definitive germinal centers or mantle zones. B-cells of similar size and shape occupied the lymphoid follicle-like nodules and stained positive for B-cell lymphoma. These cells were detected in the polyclonal B-cells by flow cytometric analysis and tested negative for CD10. Unusual B-cell proliferation was observed, but as there was no definitive evidence of B-cell lymphoma, the lesion was diagnosed as Küttner's tumor.

Conclusion

We report on a rare case of Küttner's tumor associated with fibrosclerosis and atypical lymphoid hyperplasia in both the sub-mandibular gland and regional lymph nodes. Although more cases need to be investigated, our findings might be helpful to further studies seeking to clarify the etiology of idiopathic sclerosing lesions arising in the organs and regional lymph nodes.

Chronic sclerosing sialadenitis as one of the immunoglobulin G4-related diseases: a clinicopathological study of six cases from Central Europe

AIMS

Chronic sclerosing sialadenitis (CSS) has been proposed recently to be a member of the group of IgG4-related diseases in Japanese and American series. The aim of our study was to validate these results in a cohort of European patients.

METHODS AND RESULTS

Our CSS series included four females and two males, aged 32-76 years, all presenting with unilateral swelling of submandibular gland. Microscopically, all CSS-cases showed similar morphology with preservation of lobular architecture accentuated by cellular fibrous bands, dense lymphoplasmacytic inflammation and varied acinar atrophy. Ductal lymphocytes were detected in three cases. In five cases, the presence of intraductal secretory material accompanied by parenchymal neutrophils was observed. Obliterative phlebitis was seen in three cases. The inflammatory infiltrate was composed of T and B lymphocytes and polyclonal plasma cells. The median number of IgG-positive plasma cells per high-power field (HPF) was 157; median number of IgG4-positive plasma cells per HPF was 133. Median value of the IgG4:IgG ratio was 0.84.

CONCLUSIONS

This is the first European series to demonstrate that CSS belongs to the family of IgG4-related disease. Unlike previous studies, in CSS we found rarely described ductal lymphocytes and parenchymal neutrophils. CSS displays consistent morphology with increased numbers of IgG4-positive plasma cells, and should be regarded as a member of the IgG4-related disease group.

IgG4-associated sialadenitis

PURPOSE OF REVIEW

An enlarged salivary gland or lacrimal gland raises a wide differential diagnosis that includes both benign inflammatory conditions and malignant disorders. This review aims to address the numerous controversies that have arisen regarding inflammatory diseases of the salivary gland over the past two centuries and more specifically address the relevance of IgG4 in this setting.

RECENT FINDINGS

A significant percentage of cases previously classified as Mikulicz disease, Küttner tumor, and orbital pseudotumor (idiopathic orbital inflammation) show elevated numbers of IgG4-positive plasma cells, and some of these cases also show elevated levels of serum IgG4. These data support the evolving concept of IgG4-associated sialadenitis/dacroadenitis. The disease presents with enlargement of one of more salivary gland(s) and/or lacrimal gland(s). Histologically this disease is characterized by a dense polyclonal lymphoplasmacytic infiltrate, and is frequently associated with germinal centers, fibrosis and obliterative phlebitis. IgG4-bearing plasma cells are virtually always present, as is an elevated ratio of IgG4 to IgG containing plasma cells.

SUMMARY

IgG4-related sialadenitis belongs to the IgG4-related systemic disease spectrum and shows a swift response to immunosuppression.

Clinicopathologic similarities between Mikulicz disease and Küttner tumor

PURPOSE

Recent studies have revealed that Mikulicz disease (MD) differs from Sjögren syndrome and is an immunoglobulin G(4) (IgG(4))-related systemic disease. Küttner tumor (KT) is also reported to be an IgG(4)-related disease. In this study, we examined the clinicopathologic and serologic findings in MD (39 patients) and KT (6 patients) and attempted to discern the similarities between MD and KT.

MATERIALS AND METHODS

We diagnosed 39 patients with MD and 6 patients with KT. We analyzed the clinicopathologic and serologic findings (IgG subclasses) in 39 patients with MD and 6 patients with KT. Submandibular and labial salivary gland specimens obtained from patients with MD and KT were stained with anti-IgG(4) antibodies.

RESULTS

The mean IgG(4) concentration (±SD) was 931.1 ± 796.2 mg/dL in patients with MD and 756.2 ± 449.2 mg/dL in patients with KT. Abundant infiltration of IgG(4)-positive plasmacytes into the salivary glands was observed in both patients with MD and patients with KT.

CONCLUSION

The serologic and histopathologic findings in MD and KT are very similar, and these 2 conditions may be IgG(4)-related systemic diseases.

IgG4-related sclerosing disease: a critical appraisal of an evolving clinicopathologic entity

An elevated serum titer of immunoglobulin G4 (IgG4), the least common (3% to 6%) of the 4 subclasses of IgG, is a surrogate marker for the recently characterized IgG4-related sclerosing disease. The syndrome affects predominantly middle-aged and elderly patients, with male predominance. The patients present with symptoms referable to the involvement of 1 or more sites, usually in the form of mass lesions. The prototype is IgG4-related sclerosing pancreatitis (also known as autoimmune pancreatitis), most commonly presenting as painless obstructive jaundice with or without a pancreatic mass. Other common sites of involvement are the hepatobiliary tract, salivary gland, orbit, and lymph node, but practically any organ-site can be affected, such as retroperitoneum, aorta, mediastinum, soft tissue, skin, central nervous system, breast, kidney, prostate, upper aerodigestive tract, and lung. The patients usually have a good general condition, with no fever or constitutional symptoms. Common laboratory findings include raised serum globulin, IgG, IgG4, and IgE, whereas lactate dehydrogenase is usually not raised. Some patients have low titers of autoantibodies (such as antinuclear antibodies and rheumatoid factor). The disease often shows excellent response to steroid therapy. The natural history is characterized by the development of multiple sites of involvement with time, sometimes after many years. However, the disease can remain localized to 1 site in occasional patients. The main pathologic findings in various extranodal sites include lymphoplasmacytic infiltration, lymphoid follicle formation, sclerosis and obliterative phlebitis, accompanied by atrophy and loss of the specialized structures of the involved tissue (such as secretory acini in pancreas, salivary gland, or lacrimal gland). The relative predominance of the lymphoplasmacytic and sclerotic components results in 3 histologic patterns: pseudolymphomatous, mixed, and sclerosing. Immunostaining shows increased IgG4+ cells in the involved tissues (>50 per high-power field, with IgG4/IgG ratio >40%). The lymph nodes show multicentric Castleman disease-like features, reactive follicular hyperplasia, interfollicular expansion, or progressive transformation of germinal centers, with the unifying feature being an increase in IgG4+ plasma cells on immunostaining. The nature and pathogenesis of IgG4-related sclerosing disease are still elusive. Occasionally, the disease can be complicated by the development of malignant lymphoma and possibly carcinoma.

Chronic sclerosing sialadenitis (Küttner tumor) is an IgG4-associated disease

BACKGROUND

Chronic sclerosing sialadenitis is a fibroinflammatory disease of the salivary glands, characteristically of the submandibular gland. One prior Asian study proposed that chronic sclerosing sialadenitis is a part of the spectrum of IgG4-associated disease. This association has not been confirmed in Western populations. We therefore, investigated the relationship between IgG4 and chronic sclerosing sialadenitis, and compared the histomorphologic features of this condition with those of chronic sialadenitis-not otherwise specified, Sjögren syndrome, and lymphoepithelial sialadenitis.

MATERIALS AND METHODS

We evaluated 13 cases of chronic sclerosing sialadenitis and compared them with 15 cases of chronic sialadenitis-not otherwise specified, 8 lip biopsies from individuals with Sjögren syndrome, and 4 cases of lymphoepithelial sialadenitis. Immunohistochemistry for IgG, and IgG4 was carried out. IgG4-positive plasma cells were quantified and the IgG4/IgG ratio was calculated.

RESULTS

Seven patients with chronic sclerosing sialadenitis were female and 6 were male. Their mean age was 61 years (range: 27 to 80). Twelve chronic sclerosing sialadenitis cases involved the submandibular gland (bilaterally in 3) and in 1 there was a parotid lesion. Three of these 12 cases had manifestations of IgG4-associated systemic disease. Morphologically these specimens had preservation of lobular architecture, hypercellular interlobular fibrosis, florid lymphoid hyperplasia, and numerous plasma cells. Obliterative phlebitis was observed in 6 cases. The histologic features of chronic sclerosing sialadenitis were reminiscent of autoimmune pancreatitis, and were either not observed or were present only focally in cases of chronic sialadenitis, Sjögren syndrome, and lymphoepithelial sialadenitis.Eleven of 12 evaluable cases showed an increased number of IgG4 plasma cells with a mean of 229/high-power field (HPF) (range 75 to 608) and an overall IgG4/IgG ratio of 0.86 (range 0.5 to 1). The only patient whose biopsy lacked IgG4-positive plasma cells had pathologic evidence of cytomegalovirus infection. Chronic sclerosing sialadenitis cases, in comparison with the other 3 groups studied, showed a significantly higher number of IgG4 positive plasma cells (P<0.05). Patients with chronic sialadenitis-not otherwise specified had a median number of only 16 IgG4-positive plasma cells/HPF (range 2 to 44), with an IgG4/IgG ratio of 0.14 (range 0.02 to 0.28). The Sjögren syndrome patients had a median of 1 IgG4-positive plasma cell/HPF (range 0 to 3), with an IgG4/IgG ratio of 0.02 (range 0 to 0.07). Patients with lymphoepithelial sialadenitis had a median of 0 IgG4-positive plasma cells per HPF.

CONCLUSION

Chronic sclerosing sialadenitis has a characteristic morphologic appearance. This morphologic appearance, in conjunction with the elevated IgG4 expression, distinguishes chronic sclerosing sialadenitis from other inflammatory diseases of the salivary glands. Chronic sclerosing sialadenitis belongs to the spectrum of IgG4-related diseases.

Lymphoplasmacytic Infiltrate of Regional Lymph Nodes in Küttner's Tumor (Chronic Sclerosing Sialadenitis): A Report of 3 Cases

Regional lymph nodes of Küttner's tumor from 3 patients showed reactive follicular hyperplasia and prominent interfollicular plasmacytosis. The patients were 71-, 57-, and 73-year-old Japanese men. The polytypic nature of plasma cells was demonstrated by immunohistochemistry. There were numerous IgG-positive plasma cells with scattered IgA-positive or IgM-positive plasma cells. IgG4-positive cells comprised 25% to 40% of IgG-positive plasma cells. Prominent polyclonal hyperimmunoglobulinemia was demonstrated on laboratory test in 2 cases examined. An elevated serum IgG4 level (16%) was also demonstrated in 1 patient. The present 3 cases indicated that regional lymph node of Küttner's tumor may show reactive follicular hyperplasia and prominent interfollicular plasmacytosis and should be differentiated from various benign and malignant lymphoproliferative disorders including systemic rheumatic disease, plasma cell type of Castleman disease, and lymph node involvement of marginal B-cell lymphoma of the mucosa-associated lymphoid tissue type showing prominent plasma cell differentiation.

Immunoprofile of Kuttner Tumor (Chronic Sclerosing Sialadenitis)

In the present study, the immunoprofile of chronic sclerosing sialadenitis, also known as Kuttner tumor, was analyzed. Two cases that occurred in the submandibular gland of male patients were submitted to immunohistochemical reactions to different antibodies. Histological examinations showed a submandibular gland exhibiting various degrees of atrophy with destruction of acini, infiltration by inflammatory cells, and periductal fibrosis. Reactions to cytokeratins (CKs) showed acini and duct remnants positive to CKs 7, 8, 19, and 13. CK14 stained myoepithelial cells around preserved acini and intercalated duct, and also basal cell of excretory ducts, but was negative in proliferating and branching ducts. Smooth muscle actin (SMA) was expressed by myofibroblasts in periductal fibrosis, and an intense expression of extracellular components was also seen. Lymphocyte markers showed, besides mature follicles, a higher presence of CD45RO positive cells. Thus, the immunoprofile of Kuttner is much more in keeping with an inflammatory-induced degenerative disease than with a preneoplastic lesion.

Advances in salivary gland pathology

This review summarizes the new findings on salivary gland pathology under the following categories: immunohistochemistry; molecular genetics; newly recognized tumour types; known tumour entities with new findings; and progression of salivary gland tumours. In the application of immunohistochemistry, CD117 can aid in highlighting the luminal cell component of various salivary gland tumours, whereas p63 or maspin can aid in highlighting the abluminal cell component. A high Ki67 index remains the most useful marker to predict adverse outcome in salivary gland carcinoma. Specific chromosomal translocations are recognized in pleomorphic adenoma (with translocation involving PLGA1 or HMGA2 gene) and mucoepidermoid carcinoma (with MECT1-MAML2 gene fusion). Newly recognized entities include: sclerosing polycystic adenosis (with recent molecular evidence supporting its neoplastic nature), sclerosing mucoepidermoid carcinoma with eosinophilia, keratocystoma, adenoma with additional stromal component (lymphadenoma, lipoadenoma and adenofibroma), cribriform adenocarcinoma of the tongue and signet ring adenocarcinoma of minor salivary gland. Known tumour entities with new findings include: salivary duct carcinoma (with newly recognized mucinous, micropapillary and sarcomatoid variants), intraductal carcinoma (with controversies in terminology), mucoepidermoid carcinoma (with newly proposed grading parameters and oncocytic variant), epithelial-myoepithelial carcinoma (with newly recognized morphological variants), small cell carcinoma (with most cases being related to Merkel cell carcinoma), extranodal marginal zone B-cell lymphoma (with specific chromosomal translocation) and chronic sclerosing sialadenitis (being a component of IgG4-related sclerosing disease). Progression of salivary gland tumours can take the form of malignant transformation of a benign tumour, progression from low-grade to high-grade carcinoma, dedifferentiation, or stromal invasion of an in situ carcinoma.

Epithelioid Cell Clusters With an Extensive Lymphoid Background

Context.—Fine-needle aspiration of salivary gland lesions can be particularly challenging for pathologists. There are numerous neoplasms that occur in this area and several cytologic variations of each specific lesion.

Objective.—To present and discuss a practical pattern recognition approach to fine-needle aspiration diagnosis, which includes categorizing lesions that share a certain overall cytologic architectural pattern, followed by identifying unique cellular characteristics that are specific to a certain lesion. An extensive discussion of one cytologic common pattern of salivary gland lesions, “epithelioid cell clusters with an extensive lymphoid background,” is presented. The pathologic entities that fall under this architectural pattern group are discussed, with an emphasis on neoplasms.

Data Sources.—Published literature and personal experience.

Conclusions.—A practical cytologic architectural pattern method can aid the pathologist in rendering a correct diagnosis when evaluating salivary gland lesions. One common pattern in salivary gland cytopathology is epithelioid cell clusters with an extensive lymphoid background. This pattern is often associated with Warthin tumor; however, other benign and malignant entities fall under this diagnostic group. Unique cytologic features separate these lesions into their respective diagnostic category.

Küttner's tumor of the submandibular glands: Report of five cases with fine-needle aspiration cytology

Küttner's tumor (KT) is a benign tumor-like lesion of the salivary gland that mimics neoplasm clinically because of presentation as a hard mass. Recently, the histomorphological and immunohistochemical findings of this lesion have been analyzed, and differential diagnostic problems relating to salivary gland lymphoma have been discussed. However, currently there is little information on the cytological findings of those lesions. We present cytological findings from five such cases using fine-needle aspiration cytology (FNAC). FNAC of this lesion may present a diagnostic challenge to the cytologist as lesions share some cytologic features with inflammatory process containing numerous lymphoid cells. Smears obtained from two cases contained moderate to large numbers of lymphoid cells without definite cytological atypia, scattered ductal structures, and acinar cell clusters. The remaining three cases showed low cellularity probably attributable to fibrosis that made it difficult to aspirate the cellular element. FNAC findings of scattered ductal structures surrounded by collagens and infiltrated by a mixed population of lymphoid cells, not specific for KT, are highly suggestive of the diagnosis with the appropriate clinical findings. However, a portion of cytological specimens of KT containing relatively large numbers of lymphoid cells should be differentiated from malignant lymphoma arising from the submandibular gland.

IgG4-related sclerosing disease incorporating sclerosing pancreatitis, cholangitis, sialadenitis and retroperitoneal fibrosis with lymphadenopathy

BACKGROUND AND AIMS

Autoimmune pancreatitis is usually associated with elevated serum IgG4 concentrations, and sometimes with sclerosing cholangitis and Sjögren's syndrome. This study aimed to elucidate the proposed entity of IgG4-related sclerosing disease.

METHODS

Subjects were patients with autoimmune pancreatitis (n = 26), sclerosing sialadenitis (n = 5), chronic alcoholic pancreatitis (n = 20), sialolithiasis (n = 34), Sjögren's syndrome (n = 50), and primary sclerosing cholangitis (n = 3). Sections of various organs and tissues of these patients were examined immunohistochemically using antibodies to CD4-T, CD8-T, and CD20-B cell subsets and IgG4, and serum IgG4 concentrations were measured.

RESULTS

Patients with autoimmune pancreatitis were associated with sclerosing cholangitis (n = 23), sclerosing sialadenitis (n = 2), retroperitoneal fibrosis (n = 2), and abdominal (n = 5) and cervical (n = 4) lymphadenopathy. They demonstrated infiltrations of more abundant IgG4-positive plasma cells in the pancreas, peripancreatic retroperitoneal tissues, extrahepatic bile duct, gallbladder, stomach, minor salivary gland, and abdominal lymph nodes compared with those of other diseases (p < 0.01). Such infiltrations were also observed in the minor salivary gland and submandibular gland of patients with sclerosing sialadenitis (p < 0.01). Serum IgG4 concentrations were significantly elevated in patients with autoimmune pancreatitis and sclerosing sialadenitis (p < 0.01).

CONCLUSION

We propose a new clinicopathological entity of IgG4-related sclerosing disease incorporating sclerosing pancreatitis, cholangitis, sialadenitis and retroperitoneal fibrosis with lymphadenopathy.

Abundant IgG4-positive plasma cell infiltration characterizes chronic sclerosing sialadenitis (Küttner's tumor)

Chronic sclerosing sialadenitis (CSS) is a cryptogenic tumor-like condition of the salivary gland(s). While immune-mediated processes are suspected in its pathogenesis, and CSS is occasionally reported to be associated with sclerosing pancreatitis, an IgG4-related disease, the exact immunopathologic processes of CSS remain speculative. In this study, we examined the clinicopathologic findings of CSS (12 cases) in comparison with sialolithiasis (8 cases) and Sjogren's syndrome (13 cases), and tried to clarify whether CSS is an IgG4-related disease or not. Submandibular gland(s) were affected in all cases of CSS. CSS cases could be divided into two types: 5 cases were associated with sclerosing lesions in extrasalivary glandular tissue (systemic type), while only salivary gland(s) were affected in the remaining 7 cases (localized type). In the former type, which showed male predominance, bilateral salivary glands were frequently affected, and eosinophilia and elevations of gamma-globulin and IgG in serum were frequently found. Histologically, all cases of CSS showed marked lymphoplasmacytic infiltration admixed with fibrosis and the destruction of glandular lobules. Obliterative phlebitis was found in the affected salivary glands in all cases of CSS. Immunohistochemically, the proportion of IgG4/IgG-positive plasma cells was more than 45% in CSS, while it was less than 5% in controls. The resemblance of the clinicopathologic features of CSS with those of sclerosing pancreatitis suggests the participation of a similar immunopathologic process with IgG4 disturbance in CSS. The abundance of IgG4-positive plasma cells in the lesions would be useful for distinguishing CSS from other forms of sialadenitis.

Küttner's tumor: unusual presentation with bilateral involvement of the lacrimal and submandibular glands

Chronic sclerosing sialadenitis, known as Küttner's tumor (KT), is a chronic inflammatory disease of the salivary gland characterized by progressive periductal fibrosis, dilated ducts with a dense lymphocyte infiltration and lymphoid follicle formation, and acinar atropy. We report a unique case of KT in a 30-year-old female who presented with time-serial involvement of the bilateral lacrimal and submandibular glands with reactive follicular hyperplasia of bilateral upper cervical lymph nodes. All tissue samples of the submandibular and lacrimal glands were typical of KT on pathologic examination. There was no evidence of lymphoepithelial lesions or intraepithelial lymphocytes. This is the first case of KT involving both lacrimal and submandibular glands, suggesting that KT is closely related to an active local immune process.

A case of Kuttner tumor of the submandibular gland

Kuttner tumor (known as chronic sclerosing sialadenitis) is a totally benign inflammatory lesion and to date there has been no report of malignancy. However, because of its clinical features, the clinical diagnosis is often that of a salivary gland neoplasm. We report a case of Kuttner tumor and discuss its differential diagnosis, especially the pathological diagnosis. Kuttner tumor may be mainly due to T lymphocyte immune reaction and of itself is a benign lesion, but it may provide a state in which a malignant lesion arises.

Chronic sclerosing sialadenitis of the parotid gland

Chronic sclerosing sialadenitis (Küttner's tumor) is a benign and chronic inflammatory condition of the submandibular gland that clinically cannot be easily distinguished from salivary malignant neoplasia. This is a report of a case of chronic sclerosing sialadenitis located as a solitary mass in an accessory parotid gland.

Kuttner tumour (chronic sclerosing sialadenitis) of the submandibular gland: sonographic appearances

Patients with Kuttner tumours present with clinical features simulating a submandibular tumour. This article aims to familiarise sonologists with the sonographic appearances of these tumours, to help in their differentiation from other salivary lesions. In 13 patients with histologically or cytologically proven Kuttner tumours, the features evaluated on sonography included: shape and border of the gland, internal architecture, duct dilatation, presence/absence of calculi and presence and distribution of vascularity. There was diffuse involvement of the submandibular glands in 11 patients and focal involvement in 2. The majority (9 of 11) of the patients with diffuse involvement showed sonographic appearances simulating a "cirrhotic" liver; 2 showed diffuse heterogeneous involvement with duct dilatation and calculus. Doppler showed prominent intraglandular vessels, with no evidence of displacement. Focal lesions (2 of 11) were seen as hypoechoic, heterogeneous "masses," with a radial branching vascular pattern within, on Doppler. In conclusion, sonographic features may help in identifying Kuttner tumours of the submandibular glands.

Kuttner tumor (chronic sclerosing sialadenitis)

Kuttner tumor (KT), known descriptively as chronic sclerosing sialadenitis, is a chronic inflammatory disease of the salivary gland. Clinically, it produces a firm swelling of the glands and may be difficult to distinguish from neoplasia. The diagnosis can only be made histologically and should not be difficult if the pathologist is aware of the condition's existence. Errors in diagnosis arise because KT is underrecognized and few cases have been reported in the English literature. We present a case of KT initially diagnosed as a primary salivary gland neoplasm that intraoperative frozen section revealed to be chronic sclerosing sialadenitis. Excision of the mass, usually carried out diagnostically, is adequate treatment.

Kuttner tumor of the submandibular gland: fine-needle aspiration cytologic findings of seven cases

Kuttner tumor or chronic sclerosing sialadenitis is a benign inflammatory condition of the submandibular gland that mimics a malignant neoplasm clinically because of presentation as a hard mass. This is an underrecognized entity in the surgical pathology and cytology literature. We describe thefine-needle aspiration cytologic findings of 7 cases with histologic correlation. The 6 men and 1 woman (age, 47-72 years) had unilateral (4 cases) or bilateral (3 cases) submandibular masses known to be present for 1 month to 6 years (mean, 15 months). The aspirates were paucicellular to moderately cellular. They were characterized by scattered tubular ductal structures often enveloped by collagen bundles or lymphoplasmacytic infiltrate, isolated fragments of fibrous stroma, a background rich in lymphoid cells, and paucity or absence of acini. Histologic examination of the excised submandibular glands revealed preserved lobular architecture, thickening of interlobular septa by sclerotic tissue, dense lymphoplasmacytic infiltrate, preservation of ducts with periductal fibrosis, and variable loss of acini. In combination with the clinical findings, the fine-needle aspiration cytologic findings can strongly suggest the diagnosis of Kuttner tumor and may obviate the need of surgical intervention.