Primary Sjögren's syndrome misdiagnosed as Mikulicz's disease: a case report.

BACKGROUND: Sjögren's Syndrome (SS) is an inflammatory autoimmune disease, and Mikulicz's disease (MD) is a lymphoproliferative disorder. Both MD and SS are more common in middle-aged female, and the dry eyes could be presented in both of them with different degree. The MD patients are characterized by symmetrical swelling of the lacrimal glands which also can occur in the early stage of SS. And the imaging findings between early stage of SS and MD are lack of specificity. Therefore, SS and MD have similarities in the clinical manifestations, imaging and pathological findings and are confused in diagnosis. CASE PRESENTATION: A 51-year-old female patient presented with bilateral swelling of the upper eyelids for 2 years. She also reported having dry mouth and dry eyes which could be tolerated. The Schirmer's test result is positive and the laboratory tests indicate serum total IgG increased. In the bilateral lacrimal gland area could palpate soft masses. The orbital magnetic resonance imaging (MRI) examination showed bilateral lacrimal gland prolapse. While the histopathological result was considered as MD. The immunohistochemical (IHC) staining results were positive for IgG and negative for IgG4. To clarify the diagnosis, SS-related laboratory tests were performed: anti-SSA antibody (+++), anti-SSB antibody (+++), anti-Ro-52 antibody (+++). With a comprehensive consideration, the final diagnosis was SS. CONCLUSION: When the clinical manifestations are atypical, it is necessary to pay attention to the differential diagnosis of SS and MD.

Differentiation between IgG4-related Mikulicz disease and Sjögren's syndrome: A review case report and literature review.

RATIONALE: IgG4-related diseases cause lesions in various organs throughout the body. In otorhinolaryngology, IgG4-related Mikulicz's disease is suspected and diagnosed based on the presence of lesions of the head and neck, salivary and lacrimal gland enlargement, and bilateral sinus opacity concentrated on the maxillary sinuses. However, in some cases, it is necessary to consider about differentiation between IgG4-related Mikulicz's disease and Sjögren syndrome. PATIENT CONCERNS AND DIAGNOSIS: A 75-years-old male patient visited our hospital with bilateral otitis media with effusion, which was resistant to conservative treatment. Other symptoms at presentation included enlarged bilateral submandibular and sublingual glands marked oral dryness, severe decrease in saliva secretion (1 mL/10 minutes), and dry eyes. We conducted a Schirmer's and fluorescent dye tests, both of which were positive. High serum IgG4 levels were observed, and although the Sjögren syndrome (SS)-A/SS-B antibodies were negative, marked hypolacrimation and tear secretion were observed. Therefore, a detailed examination considering both IgG4-related Mikulicz's disease and SS was conducted. Salivary gland scintigraphy performed prior to the salivary gland biopsy revealed a marked decrease in uptake, which satisfied the diagnostic criteria for SS; however, it was difficult to diagnose IgG4-related disease based on the diagnostic definition. INTERVENSIONS: Although a definitive diagnosis of SS was made, the persistent otitis media with effusion that was resistant to conservative treatment and bilateral mixed hearing loss were confirmed. As mixed hearing loss is considered an otological symptom of IgG4-related disease, oral steroid treatment was administered. OUTCOME: Thereafter, marked recovery of hearing and reduced swelling and induration of the bilateral parotid and submandibular glands were observed. Clinically, IgG4-related Mikulicz's disease was strongly suspected, but a definite diagnosis of SS was made. LESSONS: In the absence of an IgG4-related Mikulicz's disease diagnosis, careful differentiation between IgG4-related Mikulicz's disease and 2 diseases and their diagnostic criteria was essential.

Pathology of salivary gland dysfunction and restoration of function.

In this review, the author shows that simultaneous multiple disorders caused by reactivation of Epstein-Barr virus can lead to salivary gland disorders as part of Sjogren's syndrome (SS). Therefore, clinicians must differentiate SS from other diseases when diagnosing and treating salivary gland disorders. In particular, the author explains how microbial infection in SS overcomes immunological tolerance, leading to pathological changes, and how cytokine overexpression and endocrine disrupters contribute to glandular tissue injury. Also, the author suggests that involvement of reactive oxygen species is a common pathogenesis of salivary gland disorders and SS, so regulation of oxidative stress is an effective treatment for both. The results of clinical studies on restoring salivary gland function and regenerating salivary glands with tissue stem cells may provide clues on elucidating the cause of SS.

Genes and pathways associated with the occurrence of malignancy in benign lymphoepithelial lesions.

There is increasing evidence concerning the occurrence of malignant lymphoma among people suffering from Mikulicz disease, also termed benign lymphoepithelial lesion (BLEL) and immunoglobulin G4­associated disease. However, the underlying molecular mechanism of the malignant transformation remains unclear. The present study aimed to investigate the gene expression profile between BLEL and malignant lymphoepithelial lesion (MLEL) conditions using tissue microarray analysis, to identify genes and pathways which may be associated with the risk of malignant transformation. Comparing gene expression profiles between BLEL tissues (n=13) and MLEL (n=14), a total of 1,002 differentially expressed genes (DEGs) were identified including 364 downregulated and 638 upregulated DEGs in BLEL. The downregulated DEGs in BLEL were frequently associated with immune­based functions, immune cell differentiation, proliferation and survival, and metabolic functions, whereas the upregulated DEGs were primarily associated with organ, gland and tissue developmental processes. The B cell receptor signaling pathway, the transcription factor p65 signaling pathway, low affinity immunoglobulin γ Fc region receptor II­mediated phagocytosis, the high affinity immunoglobulin ε receptor subunit γ signaling pathway and Epstein­Barr virus infection, and pathways in cancer, were the pathways associated with the downregulated DEGs. The upregulated DEGs were associated with three pathways, including glutathione metabolism, salivary secretion and mineral absorption pathways. These results suggested that the identified signaling pathways and their associated genes may be crucial for understanding the molecular mechanisms underlying malignant transformation from BLEL, and they may be considered to be markers for predicting malignancy among the BLEL group.

Complement System in the Pathogenesis of Benign Lymphoepithelial Lesions of the Lacrimal Gland.

OBJECTIVE: We aimed to examine the potential involvement of local complement system gene expression in the pathogenesis of benign lymphoepithelial lesions (BLEL) of the lacrimal gland. METHODS: We collected data from 9 consecutive pathologically confirmed patients with BLEL of the lacrimal gland and 9 cases with orbital cavernous hemangioma as a control group, and adopted whole genome microarray to screen complement system-related differential genes, followed by RT-PCR verification and in-depth enrichment analysis (Gene Ontology analysis) of the gene sets. RESULTS: The expression of 14 complement system-related genes in the pathologic tissue, including C2, C3, ITGB2, CR2, C1QB, CR1, ITGAX, CFP, C1QA, C4B|C4A, FANCA, C1QC, C3AR1 and CFHR4, were significantly upregulated while 7 other complement system-related genes, C5, CFI, CFHR1|CFH, CFH, CD55, CR1L and CFD were significantly downregulated in the lacrimal glands of BLEL patients. The microarray results were consistent with RT-PCR analysis results. Immunohistochemistry analysis of C3c and C1q complement component proteins in the resected tissue were positive in BLEL patients, while the control group had negative expression of these proteins. Gene ontology (GO) analysis revealed that activation of the genes of complement system-mediated signaling pathways were the most enriched differential gene group in BLEL patients. CONCLUSIONS: Local expression of complement components is prominently abnormal in BLEL, and may well play a role in its pathogenesis.

Concomitant occurrence of Mikulicz's disease and immunoglobulin G4-related chronic rhinosinusitis: a clinicopathological study of 12 cases.

AIMS: Concomitant occurrence of Mikulicz's disease (MD) and immunoglobulin (Ig)G4-related chronic rhinosinusitis (IgG4-related CRS) is extremely rare. We evaluated the clinicopathological features of MD patients with concomitant IgG4-related CRS (CRS-MD). METHODS AND RESULTS: Twelve CRS-MD patients were evaluated clinically and biopsy samples were taken from the lacrimal/salivary glands (n = 12) and nasal mucosa (n = 7) for assessment of IgG4-positive cells, using immunohistochemical techniques. Similarly, nine MD patients and 10 patients with common CRS were evaluated as controls. CRS-MD patients had higher serum IgG and IgG4 concentrations than MD patients (P < 0.05 for both). Lymphoplasmacytic infiltration, lymphoid follicle formation and sclerosis was prominent in the lacrimal/salivary glands in both groups; however, the magnitude of IgG4-positive plasma cells infiltration in the CRS-MD group was significantly higher compared to the MD group (P = 0.004). Similarly, evaluation of nasal mucosa revealed greater lymphocyte, plasma cell and eosinophil infiltration and lymphoid follicle formation, together with significantly higher IgG4-positive plasma cell infiltration in the CRS-MD group compared to the common CRS group (P = 0.004). CONCLUSIONS: Concomitant MD and IgG4-related CRS were characterized by a combination of IgG4-positive plasma cells infiltration in the lacrimal/salivary glands and the nasal mucosa and increased serum IgG4.

Immunology of IgG4-related disease.

Immunoglobulin G4-related disease (IgG4-RD) is a fibroinflammatory condition that derives its name from the characteristic finding of abundant IgG4(+) plasma cells in affected tissues, as well as the presence of elevated serum IgG4 concentrations in many patients. In contrast to fibrotic disorders, such as systemic sclerosis or idiopathic pulmonary fibrosis in which the tissues fibrosis has remained largely intractable to treatment, many IgG4-RD patients appear to have a condition in which the collagen deposition is reversible. The mechanisms underlying this peculiar feature remain unknown, but the remarkable efficacy of B cell depletion in these patients supports an important pathogenic role of B cell/T cell collaboration. In particular, aberrant T helper type 2 (Th2)/regulatory T cells sustained by putative autoreactive B cells have been proposed to drive collagen deposition through the production of profibrotic cytokines, but definitive demonstrations of this hypothesis are lacking. Indeed, a number of unsolved questions need to be addressed in order to fully understand the pathogenesis of IgG4-RD. These include the identification of an antigenic trigger(s), the implications (if any) of IgG4 antibodies for pathophysiology and the precise immunological mechanisms leading to fibrosis. Recent investigations have also raised the possibility that innate immunity might precede adaptive immunity, thus further complicating the pathological scenario. Here, we aim to review the most recent insights on the immunology of IgG4-RD, focusing on the relative contribution of innate and adaptive immune responses to the full pathological phenotype of this fibrotic condition. Clinical, histological and therapeutic features are also addressed.

Clinical relevance of Küttner tumour and IgG4-related dacryoadenitis and sialoadenitis.

OBJECTIVES: Küttner tumour (KT), so-called chronic sclerosing sialoadenitis, is characterised by concomitant swelling of the submandibular glands secondary to strong lymphocytic infiltration and fibrosis independent of sialolith formation. However, recent studies have indicated that some patients with KT develop high serum levels of IgG4 and infiltration of IgG4-positive plasma cells, namely IgG4-related dacryoadenitis and sialoadenitis (IgG4-DS), so-called Mikulicz's disease. The aim of this study was to clarify the clinical and pathological associations between KT and IgG4-DS. MATERIALS AND METHODS: Fifty-four patients pathologically diagnosed with KT or chronic sialoadenitis were divided into two groups according to the presence or absence of sialolith (KT-S (+) or KT-S (-), respectively). RESULTS: There were no significant differences in the clinical findings, including the mean age, sex and disease duration, between the two groups. All patients in the KT-S (+) group showed unilateral swelling without infiltration of IgG4-positive plasma cells or a history of other IgG4-related diseases (IgG4-RD), while those in the KT-S (-) group showed bilateral swelling (37.5%), strong infiltration of IgG4-positive plasma cells (87.5%) and a history of other IgG4-RD (12.5%). CONCLUSIONS: These results suggest an association between the pathogeneses of KT-S (-) and IgG4-DS, but not KT-S (+).

The diagnostic utility of biopsies from the submandibular and labial salivary glands in IgG4-related dacryoadenitis and sialoadenitis, so-called Mikulicz's disease.

IgG4-related dacryoadenitis and sialoadenitis (IgG4-DS) is characterized by serum IgG4 elevation and the infiltration of IgG4-positive plasma cells in glandular tissues. For definitive diagnosis of IgG4-DS, biopsies of local lesions are recommended to exclude Sjögren's syndrome (SS), malignant tumours, and similar disorders. In this study, we examined the diagnostic utility of submandibular gland (SMG) and labial salivary gland (LSG) biopsies in IgG4-DS. Fourteen patients presenting with swelling of the SMG (eight females and six males) underwent both SMG and LSG biopsies. The sensitivity, specificity, and accuracy of SMG biopsies were all 100.0%. In contrast, those of LSG biopsies were 69.2%, 100.0%, and 71.4%, respectively. Thirty-three out of 61 LSG biopsies (54.1%) from all 14 patients were positive for the diagnostic criteria of IgG4-DS (IgG4-positive/IgG-positive plasma cells >0.4). None of the patients experienced complications such as facial nerve palsy, sialocele, or hyposalivation. The IgG4/IgG ratio showed no significant correlation between the LSG and SMG. The final diagnosis was IgG4-DS in 13 patients and marginal zone B-cell lymphoma (MZL) in one. These results suggest that incisional biopsy of the SMG is useful and appropriate for the definitive diagnosis of IgG4-DS, while diagnosis by LSG biopsy alone requires more caution.

Mechanisms and assessment of IgG4-related disease: lessons for the rheumatologist.

Recognition of IgG4-related disease as an independent chronic inflammatory disorder is a relatively new concept; previously, the condition was thought to represent a subtype of Sjögren's syndrome. IgG4-related disease is characterized by elevated serum levels of IgG4 and inflammation of various organs, with abundant infiltration of IgG4-bearing plasma cells, storiform fibrosis and obliterative phlebitis representing the major histopathological features of the swollen organs. The aetiology and pathogenesis of this disorder remain unclear, but inflammation and subsequent fibrosis occur due to excess production of type 2 T-helper-cell and regulatory T-cell cytokines. The disease can comprise various organ manifestations, such as dacryoadenitis and sialadenitis (also called Mikulicz disease), type 1 autoimmune pancreatitis, kidney dysfunction and lung disease. Early intervention using glucocorticoids can improve IgG4-related organ dysfunction; however, patients often relapse when doses of these agents are tapered. The disease has also been associated with an increased incidence of certain malignancies. Increased awareness of IgG4-related disease might lead to consultation with rheumatologists owing to its clinical, and potentially pathogenetic, similarities with certain rheumatic disorders. With this in mind, we describe the pathogenic mechanisms of IgG4-related disease, and outline considerations for diagnosis and treatment of the condition.

IgG4-related Mikulicz's disease associated with thyroiditis: a case report and review of the literature.

PURPOSE: To report an unusual case of IgG4-related Mikulicz's disease associated with thyroiditis. CASE REPORT: We describe a 25-year-old Chinese man who presented with bilateral, painless swellings of the lachrymal glands, parotid glands, and thyroid nodules. The patient underwent left-sided dacryoadenectomy and the diagnosis of IgG4-related Mikulicz's disease was pathologically confirmed. The size of the right-sided lachrymal gland and parotid glands recovered fundamentally after one month of glucocorticoid therapy. CONCLUSION: IgG4-related Mikulicz's disease associated with thyroiditis should be considered in the differential diagnosis of bilateral swellings of lachrymal glands, salivary glands, and thyroid nodules. Surgical excision is recommended in order to treat the tumor and to ensure the pathological diagnosis. Glucocorticoid therapy should be considered in association with surgery after removal.

"Quasi-symmetric" FDG avidity of bilateral salivary glands in Mikulicz disease yielding false-positive staging in lung cancer.

A 77-year-old man with lung cancer underwent fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT). Cervical FDG uptake of variable intensity was detected corresponding to enlarged masses in the bilateral parotid and left submandibular regions. We suspected metastases from primary lung cancer or coexisting salivary gland neoplasms. Histopathological examination of the FDG-avid parotid mass revealed Mikulicz disease, an uncommon autoimmune disease involving the salivary glands. We present this case of Mikulicz disease with "quasi-symmetric" FDG avidity in the major salivary glands. We believe that salivary FDG uptake can lead to erroneous interpretation of tumor staging using PET.

Interleukin-21 contributes to germinal centre formation and immunoglobulin G4 production in IgG4-related dacryoadenitis and sialoadenitis, so-called Mikulicz's disease.

OBJECTIVES: Interleukin (IL)-21 is mainly produced by CD4 T helper (Th) cells including Th2, Th17 and follicular helper T (Tfh) cells. Recent studies have reported that IL-21 is involved in the formation of germinal centres (GCs) and class switching of IgG4. It has been suggested that IgG4-related dacryoadenitis and sialoadenitis (IgG4-DS), so-called Mikulicz's disease (MD), is distinct from Sjögren's syndrome (SS) and shows a high frequency of GC formation in salivary glands. In this study the expression of IL-21 in IgG4-DS and SS patients was examined. METHODS: Twelve patients with IgG4-DS, 15 with SS and 15 healthy subjects were screened for (1) ectopic GC formation in formalin-fixed labial salivary gland (LSG) biopsy samples; (2) expression of IL-21, Th2-, Th17- and Tfh-related molecules (cytokines, chemokine receptors and transcription factors) in LSGs; (3) relationship between IgG4/IgG ratio and mRNA expression of IL-21 in LSGs. RESULTS: mRNA expression of IL-21 and Bcl-6 in LSGs from patients with IgG4-DS was significantly higher than in patients with SS and controls. IL-21 and CXCR5 were detected by immunohistochemistry in or around GC in patients with SS and those with IgG4-DS. IL-21 was detected in infiltrating lymphocytes outside GC only in patients with IgG4-DS. Expression of IL-21 was consistent with that of Th2-related molecules while IL-17 was rarely seen in IgG4-DS. Furthermore, the expression of IL-21 in LSGs was correlated with the number of GC formations and the IgG4/IgG ratio in patients with IgG4-DS. CONCLUSIONS: These results suggest that overexpression of IL-21 by Th2 cells might play a key role in GC formation and IgG4 production in IgG4-DS.

Ocular adnexal IgG4-producing mucosa-associated lymphoid tissue lymphoma mimicking IgG4-related disease.

IgG4-related disease is a recently proposed clinical entity with several unique clinicopathological features. A chronic inflammatory state with marked fibrosis, which can often be mistaken for malignancy, especially by clinical imaging analyses, unifies these features. In the present report, we describe a case of IgG4-producing mucosa-associated lymphoid tissue lymphoma mimicking IgG4-related disease. The patient was a 55-year-old male who was being followed for right orbital tumor over 1.5 years. The lesion had recently increased in size, so a biopsy was performed. Histologically, the lesion was consistent with IgG4-related disease ; however, IgG4+ plasma cells showed immunoglobulin light-chain restriction and immunoglobulin heavy chain gene rearrangement was detected in the lesion. Therefore, the lesion was diagnosed as IgG4-producing mucosa-associated lymphoid tissue lymphoma. In conclusion, in histological diagnosis of IgG4-related disease, it is important to examine not only IgG4-immunostain but also immunoglobulin light-chain restriction.

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.

A novel clinical entity, IgG4-related disease (IgG4RD): general concept and details.

IgG4-related disease (IgG4RD) is a novel clinical disease entity characterized by elevated serum IgG4 concentration and tumefaction or tissue infiltration by IgG4-positive plasma cells. IgG4RD may be present in a certain proportion of patients with a wide variety of diseases, including Mikulicz's disease, autoimmune pancreatitis, hypophysitis, Riedel thyroiditis, interstitial pneumonitis, interstitial nephritis, prostatitis, lymphadenopathy, retroperitoneal fibrosis, inflammatory aortic aneurysm, and inflammatory pseudotumor. Although IgG4RD forms a distinct, clinically independent disease category and is attracting strong attention as a new clinical entity, many questions and problems still remain to be elucidated, including its pathogenesis, the establishment of diagnostic criteria, and the role of IgG4. Here we describe the concept of IgG4RD and up-to-date information on this emerging disease entity.

IgG4-related disease: a novel lymphoproliferative disorder discovered and established in Japan in the 21st century.

IgG4-related disease is a novel lymphoproliferative disorder that shows hyper-IgG4-γ-globulinemia and IgG4-producing plasma cell expansion in affected organs with fibrotic or sclerotic changes. Patients show systemic inflammatory conditions and various symptoms depending on the affected organ. Since the first report of patients with elevated serum IgG4 in sclerosing pancreatitis in 2001, various systemic disorders described by many names have been reported. Despite similarities in the organs involved in IgG4-related Mikulicz's disease and Sjögren's syndrome, there are marked clinical and pathological differences between these conditions. Most patients diagnosed with autoimmune pancreatitis in Japan have IgG4-related pancreatitis [Type 1 autoimmune pancreatitis (AIP), lymphoplasmacytic sclerosing pancreatitis (LPSP)], a disease distinct from some of the western type [Type 2 AIP, idiopathic duct-centric chronic pancreatitis (IDCP), autoimmune pancreatitis with granulocytic epithelial lesions (GEL)]. Diagnosis of IgG4-related disease is characterized by both elevated serum IgG4 (>135 mg/dL) and histopathological features including lymphocyte and IgG4(+) plasma cell infiltration (IgG4(+) plasma cells/IgG(+) plasma cells>40%). Differential diagnosis from other distinct disorders, such as sarcoidosis, Castleman's disease, Wegener's granulomatosis, lymphoma, cancer, and other existing conditions associated with high serum IgG4 level or abundant IgG4-bearing plasma cells in tissues is necessary. We have begun a clinical prospective study to establish a treatment strategy (Phase II prospective treatment study for IgG4-multiorgan lymphoproliferative syndrome: UMIN R000002311).

A case of IgG4-related disease with features of Mikulicz's disease, and retroperitoneal fibrosis and lymphadenopathy mimicking Castleman's disease.

A 51-year-old man developed painless enlargement of the bilateral submandibular and lacrimal glands without xerostomia or xerophthalmia in the absence of autoantibodies to SS-A (Ro) and SS-B (La). In a few years, he developed generalized lymphadenopathy, with markedly elevated serum IgG4, and a computed tomography scan revealed soft-tissue-density lesions around the abdominal aorta, a finding consistent with retroperitoneal fibrosis. Biopsy of the cervical lymph node showed an expansion of the interfollicular area by heavily infiltrating plasma cells, consistent with multicentric Castleman's disease. Immunohistochemical analysis revealed that the IgG4-positive/IgG-positive plasma cell ratio was 80%, leading us to a single diagnosis of IgG4-related disease. High-dose corticosteroid treatment resulted in prompt resolution of the physical, serological, and imaging abnormalities. Although IgG4-related disease can mimic multicentric Castleman's disease, as in our patient, the two diseases have effective but distinct treatments, and thus measurement of serum IgG4 levels and specific immunohistochemical analysis for determining the IgG4-positive/IgG-positive plasma cell ratio are recommended if IgG4-related disease is suspected.