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

Sinonasal immunoglobulin G4-related disease: a case report of an atypical and rare entity

BACKGROUND

Immunoglobulin G4-related disease is marked by extensive inflammation and fibrosis of an unknown autoimmune component, with an overall incidence ranging from 0.78 to 1.39 per 105 person-years. Sinonasal immunoglobulin G4-related disease is atypical and exceedingly uncommon in the existing literature, frequently manifesting clinically as chronic rhinosinusitis, epistaxis, and facial pain.

CASE PRESENTATION

This report describes a 25-year-old Iraqi female who has been suffering from symptoms of chronic rhinosinusitis for 8 years. Despite undergoing several surgeries, there has been no improvement in her symptoms. A tissue biopsy that revealed dense lymphoplasmocytosis with noticeable plasma cell infiltration, storiform fibrosis, and obliterative angitis, along with positive immunohistochemical staining for Immunoglobulin G4 plasma cells, finally confirmed the diagnosis of sinonasal immunoglobulin G4-related disease. The patient responded well to oral prednisolone and methotrexate treatments.

CONCLUSIONS

The main objective of the current report is to raise awareness among physicians about the significance of promptly identifying and diagnosing this rarity, thus preventing the adverse consequences linked to delayed diagnosis and treatment initiation.

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.

Common Characteristics of Sinonasal Inflammation Associated with IgG4-Related Disease and Other Chronic Inflammatory Diseases: A Retrospective Observational Study

INTRODUCTION

Immunoglobulin G4-related disease (IgG4-RD) is a systemic inflammatory disease characterized by elevated serum IgG4, tissue infiltration of IgG4-positive cells, and fibrosis. Although a number of IgG4-RD patients show sinonasal involvement, there is little known about sinonasal inflammation associated with IgG4-RD. This study aimed to describe the clinicopathological features of sinonasal inflammation associated with IgG4-RD and to compare with other inflammatory diseases, such as eosinophilic chronic rhinosinusitis (ECRS) and granulomatosis with polyangiitis (GPA).

METHODS

A retrospective analysis of clinicopathological features of patients with sinonasal lesions and high serum IgG4 was performed. Patient data were reviewed to determine whether they fulfilled the diagnostic criteria for other inflammatory diseases.

RESULTS

Six of 7 patients were diagnosed with IgG4-RD, while 1 patient was diagnosed with GPA. In the 6 patients with IgG4-RD, intranasal findings showed nasal polyps in 3 patients (50%) and nasal crusting in the 3 patients (50%). Computed tomography showed ethmoid sinus involvement in 5 patients (83%). Five of the 6 patients (83%) were diagnosed with IgG4-RD based on nasal biopsy, whereas 1 patient (17%) was diagnosed based on lacrimal gland biopsy. Four patients fulfilled the Japanese epidemiological survey of refractory ECRS (JESREC) criteria. However, none of the patients showed eosinophil infiltration. Although the patient with GPA showed high levels of serum IgG4 and tissue infiltration of IgG4-positive cells in the nasal biopsy, the patient showed common clinical features of GPA.

CONCLUSION

Patients with sinonasal inflammation associated with IgG4-RD had similar clinical characteristics with ECRS and GPA. Histopathological findings of the nasal biopsy from clinically diagnosed GPA was consistent with that of IgG4-RD. Sinonasal inflammation associated with IgG4-RD should be diagnosed based not only on tissue infiltration of IgG4-positive cells but in conjunction with clinical findings such as local nasal characteristics, involvement of other organs, and serum antineutrophil cytoplasmic antibody levels. IgG4-RD should be ruled out in patients with eosinophilia without histopathological eosinophil infiltration.

New insights into chronic rhinosinusitis associated with IgG4-related disease

IgG4-related disease (IgG4-RD) is a chronic inflammatory disorder characterized by elevated IgG4 serum levels, abundant IgG4-positive plasmacyte infiltration, and fibrosis of various organs, including the head and neck. We aimed to provide an overall review of IgG4-RD in the sinonasal region and propose a novel entity and criteria of chronic rhinosinusitis (CRS) associated with IgG4-RD as "IgG4-CRS," a distinct manifestation of IgG4-RD in the sinonasal region. Sinonasal involvement has been increasingly recognized; however, this region is not included in the classic IgG4-RD-affected organs. The clinical features of IgG4-CRS, including its prevalence and relationship with allergies and olfactory disturbances, have also been explored. Serum IgG4 levels and IgG4-positive plasma cell infiltrations, crucial diagnostic factors, have been discussed in association with IgG4-CRS pathogenesis. Fibrosis, a hallmark of IgG4-RD, is observed in sinonasal tissues; however, typical fibrosis, such as storiform fibrosis, is not usually found. Mimics or complications in eosinophilic CRS (ECRS) and antineutrophil cytoplasmic antibody-associated vasculitis (AAV) are highlighted. Treatment often involves typically effective glucocorticoids. Organ-specific diagnostic criteria for the sinonasal region have not currently been established. Hence, this review aims to foster awareness and understanding of IgG4-CRS among ENT physicians and to provide a basis for future research and diagnostic refinement.

Advancements in diagnosing IgG4-related disease of the head and neck: Navigating diagnostic pitfalls

IgG4-related disease (IgG4-RD) is an immune-mediated condition affecting nearly any organ. This review focuses on the nuances of diagnosing IgG4-RD affecting the head and neck. Salivary gland involvement, especially of the submandibular glands, often permits a definitive diagnosis on biopsy. However, elevated IgG4+ plasma cells are nonspecific and can be seen in chronic sialadenitis, lymphoma, and other mimics. Careful correlation of clinical and pathological findings is essential. Given the significant overlap with chronic sinusitis, IgG4-RD of the sinonasal region is difficult to diagnose histologically. Laryngeal and pharyngeal involvement appears rare as an isolated finding of IgG4-RD. Mastoid disease is uncommon and remains a diagnosis of exclusion. Thyroid manifestations pose challenges given unclear diagnostic criteria - Riedel's thyroiditis likely represents IgG4-RD, but the fibrosing variant of Hashimoto's thyroiditis as a form of the so-called 'IgG4-related thyroiditis' requires better characterisation. Eosinophilic angiocentric fibrosis, despite histologic similarities, only partially overlaps with IgG4-RD. This review aims to guide diagnosing IgG4-RD in the head and neck through a systematic, organ-focused discussion of the clinical context, the utility of immunostaining, histological mimics, and controversial issues that pose diagnostic pitfalls. Increased awareness of the nuances and difficulties diagnosing IgG4-RD affecting the head and neck will improve recognition of this protean disease.

IgG4 Positivity in Chronic Tonsillitis: A New Component of IgG4-Related Disease?

OBJECTIVE

Immunoglobulin G4-related disease (IgG4-RD) and chronic tonsillitis are both chronic fibroinflammatory diseases in which tissue atrophy is sometimes observed. In this study, the authors aimed to investigate the pathologic IgG4 positivity in tonsillectomy specimens and hypothesized to name it as a new clinical component of IgG4-RD if there is significant IgG4 positivity in chronic tonsillitis.

METHODS

A total of 73 patients who underwent tonsillectomy for chronic tonsillitis were included in this study. Of these, 31 patients had atrophic form chronic tonsillitis. Pathologic examinations and specific IgG4 immunohistochemical staining were performed by the same experienced pathologist in terms of IgG4-RD.

RESULTS

Sixty-three percent (n=46) of the cases were male, 37% (n=27) were female, their ages ranged from 3 to 51, and the mean age was 19.11±14.82. It was determined that 23.3% (n=17) of the cases participating in the study were IgG4-positive. When the pathologic grades of the cases were examined; it was observed that 13.7% (n=10) were Grade I, 65.8% (n=48) were Grade II, and 20.5% (n=15) were Grade III. A statistically significant difference was found between the pathology degrees of the cases according to the IgG4 groups ( P =0.001; P <0.01).

CONCLUSION

The authors concluded that as the histopathologic grades of chronic lymphoplasmacytic inflammation in tonsils specimen increase, IgG4 positivity rates also increase. Therefore, this clinical entity may be a new IgG4-related disease state in cases with chronic tonsillitis.

LEVEL OF EVIDENCE

Level II.

IgG4-related disease confined to the laryngopharynx: a case report highlighting the complexities in diagnosis for this rare cause of stridor

This case represents only the 15th reported incidence of IgG4-related disease (IgG4-RD) affecting the laryngopharynx, adding diagnostic and therapeutic data for this rare condition and helping to inform the future management of these patients. A 66-year-old man presented with airway symptoms, and investigations by otolaryngology, cardiology and respiratory teams did not provide a clear diagnosis. Repeat biopsies of the laryngopharynx eventually confirmed a clinicopathological diagnosis of IgG4-RD. Treatment with prednisolone and methotrexate was successful. When infective and malignant causes of adult stridor have been excluded, inflammatory causes should be considered. The diagnosis of IgG4-RD isolated to the laryngopharynx may be delayed when using the widely accepted American College of Rheumatology classification criteria because it excludes upper aerodigestive tract features. IgG4-RD isolated to the laryngopharynx is extremely rare. This means a multidisciplinary approach is vital in ensuring timely diagnosis and treatment. Better diagnostic criteria are also needed.

Proteomic characteristics of saliva in patients with different subgroups of IgG4-RD

Background

Immunoglobulin G4-related disease (IgG4-RD) is a newly defined disease entity, with great heterogeneity among IgG4-RD subgroups with different organ involvement patterns. Identification of the proteomic characteristics of IgG4-RD subgroups will be critical for the understanding of the pathogenic mechanisms of IgG4-RD.

Method

In this study, we performed proteomic analysis using Tandem Mass Tags (TMT) technology with "high field" mass analyzer with improved resolution and sequencing speed to investigate the proteomic profile of saliva and plasma samples from ten untreated IgG4-RD patients and five healthy controls (HCs). Differentially expressed proteins (DEPs) were identified by "t test" function in R package. Functional enrichment analysis was used to investigate pathways enriched in IgG4-RD samples.

Results

Most salivary DEPs identified in IgG4-RD patients compared with HCs were mainly enriched in neutrophil mediated GO bioprocess. Within the comparisons between four IgG4-RD subgroups, more DEPs were identified in the comparison of Mikulicz group and Head and neck group. Among four subgroups of IgG4-RD, Head and neck group showed the most distinctive proteomic expression pattern when compared with HCs. Moreover, "Neutrophil mediated process" related GO bioprocess was commonly identified between comparisons of Mikulicz group and Head and neck group, Head and neck group and Retroperitoneal aorta group, Head and neck group and HCs, IgG4-RD patients with saliva gland involvement and those without saliva gland involvement. Key DEPs that involved in this GO bioprocess were identified. Besides, we performed proteomic analysis for plasma samples between ten IgG4-RD and five HCs and there were several DEPs identified overlapped in saliva and plasma.

Conclusion

We identified multiple processes/factors and several signaling pathways in saliva that may be involved in the IgG4-RD pathogenesis.

Sinonasal IgG4-related sclerosing disease: A rare entity and challenging diagnosis

Objectives

To describe the rare presentation, imaging and histological findings, and treatments in patients with IgG4-related disease (IgG4-RD) and diagnostic pitfalls and difficulties.

Methods

Cases of sinonasal IgG4-RD were retrieved, and clinicopathological features were reviewed.

Results

Seven cases of sinonasal IgG4-RD were identified over an 11-year period, including four males and three females, with an age range of 19-66 years (median 58 years). Patients presented with symptoms related to the mass effect of the lesions or the destructive nature of the disease including fullness, swelling, obstruction, and pain. Serum IgG and IgG4 levels, IgG/IgG4 ratios, storiform fibrosis, obliterative phlebitis, and plasma cell infiltration were seen in varying proportions. Bony erosion and tissue inflammation were present in some cases.

Conclusion

Sinonasal IgG4-RD is exceedingly rare among other IgG4-RD and varied in its clinical presentation thus posing as a clinically difficult disease to diagnosis. Proper clinical, pathological, and immunohistopathological analysis is required for accurate diagnosis. Such disease should be considered in all cases of similar presentation to those in this study.Level of Evidence: 4.

Tubarial gland involvement in IgG4-related diseases

BACKGROUND

Tubarial glands (TGs) are a collection of unidentified salivary glands overlying the torus tubarius in the nasopharyngeal wall. Immunoglobulin G4-related disease (IgG4-RD) is a chronic fibroinflammatory state that often has multiple organ involvement. Involvement of the head and neck, especially the salivary glands, is common in IgG4-RD.

AIMS/OBJECTIVES

This study aimed to elucidate the clinical significance of TGs in IgG4-RD.

MATERIALS AND METHODS

We investigated the local findings of TGs in ten patients with IgG4-RD.

RESULTS

Nasopharyngeal endoscopic examination revealed oedematous swelling of the nasopharyngeal wall surrounding the TGs, which improved after steroid treatment. Moreover, sonotubometry showed a stenotic pattern in three out of seven patients with IgG4-RD.

CONCLUSIONS AND SIGNIFICANCE

TGs may be involved in IgG4-RD. The swollen TGs may be responsible for obstructive Eustachian tube dysfunction. Further studies are required to clarify the clinical significance and physiological roles of TGs in IgG4-RD.

T Cell Roles and Activity in Chronic Sclerosing Sialadenitis as IgG4-Related Disease: Current Concepts in Immunopathogenesis

IgG4-related disease is a multiorgan immunological fibroinflammatory disorder characterized by lymphoplasmacytic infiltration and fibrosis in multiple organs accompanied by high serum IgG4 levels. The salivary glands are the most common organs involved in this disease. Recently, chronic sclerosing sialadenitis affecting salivary glands, formerly known as Küttner's tumor, and Mikulicz's disease have been classified as a class of IgG4-related diseases. The etiopathobiology of IgG4-related disease is not fully understood. It has recently been hypothesized that the inflammatory and fibrotic process and the increased serum IgG4⁺ levels in IgG4-related disease are the result of an interaction between B cells and T helper cells, suggesting that T cells may play a key role in the pathogenesis of this disease. The aim of this review is to discuss the proposed roles of different T cell subsets in the pathogenesis of IgG4-related disease focusing on their roles in immunopathogenesis of IgG4-related sialadenitis.

Case Report: Diagnosis of Petrous Apex IgG4-Related Disease by Middle Cranial Fossa Craniotomy and Temporal Bone Biopsy

Introduction

Primary IgG4-related disease (IgG4-RD) of the temporal bone is a rare condition. Unlike typical petrous apicitis or Gradenigo syndrome, our patient presented exclusively with unilateral cranial nerve VI palsy and symptoms of diplopia. Skull base imaging demonstrated a destructive bony lesion in the petrous apex. Imaging and systemic investigations were insufficient to support a diagnosis. The diagnosis was achieved histologically after acquiring the specimen by middle cranial fossa craniotomy and temporal bone biopsy. This case report is thought to be the first published description of a diagnosis of IgG4-RD proven with the middle cranial fossa approach.

Case Report

We describe a 29-year-old female with primary IgG4-RD of the petrous apex of the temporal bone. This patient presented with a few-month history of left-sided headache and recent-onset diplopia due to paralysis of cranial nerve VI. Imaging demonstrated a petrous apex lesion, and comprehensive systemic investigations could not reach a diagnosis. A middle cranial fossa craniotomy and a biopsy of the temporal bone lesion were undertaken to establish the diagnosis. Histological confirmation of IgG4-RD was proven. Following treatment with corticosteroids, the patient experienced complete recovery and resolution of her symptoms.

Conclusion

This study describes a case of primary IgG4-RD of the petrous apex of the temporal bone that presented with diplopia and was diagnosed by middle fossa craniotomy and temporal bone biopsy. To the best of our knowledge, this is the first case description where primary diagnosis was made based on middle cranial fossa craniotomy and temporal bone biopsy.

The Clinical Utility of Soluble Serum Biomarkers in Autoimmune Pancreatitis: A Systematic Review

Autoimmune pancreatitis (AIP) is a rare etiological type of chronic pancreatitis. The clinical and radiological presentation of AIP often resembles that of pancreatic cancer. Identifying non-invasive markers for their early distinction is of utmost importance to avoid unnecessary surgery or a delay in steroid therapy. Thus, this systematic review was conducted to revisit all current evidence on the clinical utility of different serum biomarkers in diagnosing AIP, distinguishing AIP from pancreatic cancer, and predicting disease course, steroid therapy response, and relapse. A systematic review was performed for articles published up to August 2021 by searching electronic databases such as MEDLINE, Web of Science, and EMBASE. Among 5123 identified records, 92 studies were included in the qualitative synthesis. Apart from immunoglobulin (Ig) G4, which was by far the most studied biomarker, we identified autoantibodies against the following: lactoferrin, carboanhydrase II, plasminogen-binding protein, amylase-α2A, cationic (PRSS1) and anionic (PRSS2) trypsinogens, pancreatic secretory trypsin inhibitor (PSTI/SPINK1), and type IV collagen. The identified novel autoantigens were laminin 511, annexin A11, HSP-10, and prohibitin. Other biomarkers included cytokines, decreased complement levels, circulating immune complexes, N-glycan profile changes, aberrant miRNAs expression, decreased IgA and IgM levels, increased IgE levels and/or peripheral eosinophil count, and changes in apolipoprotein isoforms levels. To our knowledge, this is the first systematic review that addresses biomarkers in AIP. Evolving research has recognized numerous biomarkers that could help elucidate the pathophysiological mechanisms of AIP, bringing us closer to AIP diagnosis and its preoperative distinction from pancreatic cancer.

Immunoglobulin G4-Related Disease Presenting as Temporal Bone Lesion with Facial Nerve Palsy

Immunoglobulin G4-related disease (IgG4-RD) is a systemic condition which could present as local infiltration of skull base structures. We report a case of IgG4-RD with infiltration of the temporal bone and surrounding structures in a patient with systemic vasculitis on systemic steroids. A 31-year-old woman presented with right-sided facial weakness, headache, and right ear hearing loss. On examination, redness and retraction of the right tympanic membrane and facial paresis (House-Brackman IV) were noted. Computed tomography imaging showed mastoiditis, temporal lobe stroke, and brain abscess. Magnetic resonance imaging (MRI) showed infiltration in the infratemporal fossa, nasopharynx, spreading along the Eustachian tube and perineurally along the branches of CN V and CN VII intracranially, forming a dural based mass in the middle cranial fossa. Intracranial mass compressed the temporal lobe of the brain, causing perifocal brain edema. Endoscopic biopsy of the nasopharynx was chosen as the least invasive method. It showed marked fibrosis of the tissue, dense lymphoplasmacytic infiltrates, and an increased number of IGG4-positive plasma cells. Serum IgG4 levels were below the diagnostic criteria of IgG4-RD, but histological characteristics of IgG4-RD were met. The patient was treated with high-dose oral prednisolone. Resolution of symptoms, including facial nerve paresis, was observed and infiltration in the nasopharynx, infratemporal fossa decreased on subsequent MRI tests. No recurrence was noted on the follow-up of 16 months. The case presented itself as a diagnostic challenge for a multidisciplinary team to differentiate pathology caused by either IgG4-RD, systemic vasculitis, or atypic mastoiditis. MRI and histological reports were essential to establish a correct diagnosis.

IgG4-Related Disease: Mimickers and Diagnostic Pitfalls

BACKGROUND

The tendency of IgG4-related disease (IgG4-RD) to form pseudotumors, as well as its multisystemic nature, makes it the perfect mimicker of many conditions. Moreover, some clinical, serological, radiological, or histological features of the disease might be shared with some mimickers.Recently, 4 clinical phenotypes have been identified, and patients grouped in each phenotype have distinctive demographic, clinical, and serological features and outcomes, and, as expected, for each phenotype, a set of differential diagnoses should be considered.

SUMMARY OF THE LITERATURE

The main differential diagnoses for the pancreato-hepato-biliary phenotype are pancreatic adenocarcinoma and cholangiocarcinoma. Other differential diagnoses include type 2 autoimmune pancreatitis and primary sclerosing cholangitis. In patients with retroperitoneal/aortic phenotype, inflammatory conditions such as idiopathic retroperitoneal fibrosis and large vessel vasculitides should be ruled out, and most of the time, a biopsy will be needed to exclude malignancies. In head and neck limited phenotype, autoimmune conditions (eg, granulomatosis with polyangiitis, Graves orbitopathy, sarcoidosis), malignancies, and histiocytosis should be ruled out, whereas the main differential diagnoses of the Mikulicz/systemic phenotype are Sjögren syndrome, granulomatosis with polyangiitis, and multicentric Castleman disease.

CONCLUSIONS

Approaching a patient with probable IgG4-RD through a clinical phenotype framework will ease the diagnostic algorithm and facilitate the prompt recognition of the disease. There are certain clinical, serological, radiological, and histological features in each clinical phenotype that, if present, increase the likelihood that a patient may have IgG4-RD instead of the mimicker condition. Those clues that point toward IgG4-RD diagnosis should be actively sought in the workup of patients.

Sinonasal immunoglobin G4-related disease: case report and review

Immunoglobin G4-related disease (IgG4-RD) is a chronic fibro-inflammatory condition that presents as a single or multiple tumefactive lesions affecting virtually any organ system. Here we report a case of recurrent sinonasal IgG4-RD and review the literature of this evolving entity.

Abnormal [18F]fluorodeoxyglucose accumulation to tori tubarius in IgG4-related disease

OBJECTIVES

Tubarial glands (TGs) are recently refocused gland tissues localized near the tori tubarius in the nasopharynx and their clinical relevance is not clear yet. IgG4-related disease (IgG4-RD) is a progressive fibrosing condition and salivary glands are well-affected lesions. The aim of the present study is to examine [¹⁸F]fluorodeoxyglucose ([¹⁸F]FDG) accumulation to the tori tubarius in IgG4-related disease (IgG4-RD).

METHODS

48 patients with IgG4-RD who underwent positron emission tomography (PET) scanning with [¹⁸F]FDG were included and semi-quantitative analysis of [¹⁸F]FDG accumulation to tori tubarius was performed along with the clinical features and histopathological analysis.

RESULTS

Of the 48 patients, abnormal [¹⁸F]FDG accumulation (metabolic tumour volume ≥ 1) to tori tubarius was observed in 15 (31.3%), all of whom had lesions in other head and neck glands. IgG4-RD patients with abnormal [¹⁸F]FDG accumulation to tori tubarius showed swollen nasopharyngeal walls around tori tubarius and forceps biopsy of the lesion revealed acinar cells and IgG4-positive plasma cells histologically. Abnormal [¹⁸F]FDG accumulation (maximum standard uptake value, metabolic tumour volume and total lesion glycolysis) to tori tubarius correlated with higher IgG4 and lower IgA serum concentrations.

CONCLUSIONS

Abnormal [¹⁸F]FDG accumulation to tori tubarius can be observed in patients with IgG4-RD and the abnormal [¹⁸F]FDG accumulation to tori tubarius can be a clue of TG involvement in IgG4-RD.

Imaging of Petrous Apex Lesions

The petrous apex may be affected by a range of lesions, commonly encountered as incidental and asymptomatic findings on imaging performed for other clinical reasons. Symptoms associated with petrous apex lesions commonly relate to mass effect and/or direct involvement of closely adjacent structures. Petrous apex lesions are optimally assessed using a combination of high-resolution CT and MRI of the skull base. Management of petrous apex lesions varies widely, reflecting the range of possible pathologies, with imaging playing a key role, including lesion characterization, surveillance, surgical planning, and oncological contouring.

Synchronous occurrence of IgG4-related sialadenitis and ductal carcinoma of the parotid gland: a case report

Immunoglobulin G4-related disease (IgG4-RD) is a rare chronic systemic inflammatory pathology that poses a diagnostic challenge since it can simulate malignancy when it affects a salivary gland as a mass-like lesion. Here, the authors report an unusual clinical case of a 42-year-old man who presented with a painless, slow-growing swelling located in the right parotid gland with a 12-month evolution. Based on imaging tests and open biopsy, a diagnosis of chronic parotitis was presumed and oral methylprednisolone was prescribed. Due to poor response to medication, a total parotidectomy preserving the facial nerve was performed. The final pathology described a unilateral IgG4-related sialadenitis (IgG4-RS) in the parotid gland in combination with a poorly differentiated multifocal ductal carcinoma. The postoperative course was uneventful except for a temporary facial paresis (grade III according to the House-Brackmann classification system) that resolved completely within 5 months. There were no systemic manifestations on the whole-body 18F-FDG PET/CT. Adjuvant radiotherapy was administered without complications. Twenty-four months follow-up after surgery showed no recurrence or evidence of systemic involvement. This clinical report highlights the importance of considering the synchronous occurrence of a carcinoma underlying an isolated parotid gland mass in the context of IgG4-RS, especially if there is no response to prior steroid medication.

18F-FDG PET/CT Manifestations of IgG4-related Disease

Immunoglobulin G4-related disease (IgG4-RD) was not recognised as a systemic condition until 2003, when extra pancreatic manifestations were identified in patients with autoimmune pancreatitis. Since then, IgG4-RD has been described to involve virtually every organ system. It is highly responsive to immunosuppressants but can have detrimental effects if left untreated. Early recognition of the disease is, therefore, critical. The diagnosis of IgG4-RD is frequently challenging owing to its non-specific clinical manifestations, indolent nature and broad differential diagnoses. Although histopathological examination remains the cornerstone of diagnosis, imaging plays an important role in establishing extent of disease and identifying areas suitable for biopsy. ¹⁸F-Fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) has been demonstrated to be useful in assessing organ involvement, guiding biopsy and monitoring disease response. The ¹⁸F-FDG PET/CT scan is highly sensitive and able to evaluate multiorgan involvement in a single examination, a key advantage over conventional imaging modalities. A potential pitfall is its low specificity. As such, detailed knowledge of the imaging findings in IgG4-related disease is required to avoid misdiagnosis. This pictorial review aims to depict the diverse spectrum of imaging findings of IgG4-RD and the key imaging features to distinguish it from other important differential diagnoses.

Atypical IgG4-related disease limited to the sino-nasal cavity: A case report

Given the overlapping clinical features of sino-nasal immunoglobulin 4-related disease (IgG4-RD) to rhinitis or rhinosinusitis, this paper aims to delineate this rare, isolated manifestation significant to physicians for their daily practice and researchers contributing to this field.

Involvement of Multiple Trigeminal Nerve Branches in IgG4-Related Orbital Disease

PURPOSE

To describe the occurrence of multiple trigeminal nerves (TGNs) enlargement in patients with orbital IgG4-related disease.

METHODS

Retrospective review of MRI findings and medical records of 6 patients (10 orbits) with orbital IgG4-related disease and enlargement of more than 1 TGN. Orbital biopsies were performed in all cases revealing the typical lymphoplasmacytic infiltrate with significant plasma cell positivity for IgG4 (IgG4+/IgG ratio ≥ 40%). Three experienced neuroradiologists reviewed the MRI sequences using a digital imaging viewer system (Horos, https://horosproject.org/).

RESULTS

Bilateral involvement of at least 2 TGNs divisions was detected in all 6 patients. Enlargement of both V1 and V2 nerves was diagnosed in 5 patients, and in 3 cases, all TGN divisions were involved. V2 nerves were the most affected. In this division, all 12 infraorbital nerves were enlarged, followed by lesser palatines (10/83.3%), superior alveolar (10/83.3%), and zygomatic (6/50%). V1 and V3 nerves were less affected albeit 9 (75%) frontal branches (V1), and 50% of the inferior alveolar (V3) nerves were also enlarged.

CONCLUSIONS

Widespread involvement of the TGN is an important feature of IgG4-related disease.

Sinonasal IgG4-related disease: a rare and emerging entity broadening the differential diagnosis in the sinonasal universe

BACKGROUND

IgG4-related disease (IgG4-RD) is a multi-organ immune-mediated disorder characterized by fibroinflammatory mass-forming lesions, mimicking malignancy or infection. While well-documented in salivary glands, orbit and thyroid in the head and neck, sinonasal IgG4-RD is rare.

METHODS

Cases of sinonasal IgG4-RD were retrieved, and clinicopathological features reviewed.

RESULTS

Seven cases of sinonasal IgG4-RD were identified over a 2-year period, including three males and four females, with an age range of 13-48 years (median: 32 years). Patients presented with cheek swelling, pain and visual disturbances. Serum IgG4 levels were mildly elevated. Storiform fibrosis, obliterative phlebitis and plasma cell infiltration were seen in varying proportions. Destruction of bone and subepithelial mucoserous glands was present. ALK-1 negativity distinguished from inflammatory myofibroblastic tumor.

CONCLUSION

Sinonasal IgG4-RD expands the growing spectrum of IgG4-RD. A high degree of suspicion is required to include IgG4-RD in differential diagnosis of sinonasal masses, and perform detailed histological and immunohistochemical workup for accurate diagnosis.

Localized IgG4-related disease manifested on the tongue: a case report

Immunoglobulin G4-related disease (IgG4-RD) is an immune-mediated fibroinflammatory condition that can affect multiple organs. IgG4-RD may show a variety of initial symptoms. In the oral mucosa, lesions present as inflammatory fibrosis with a large number of IgG4-positive plasma cells. Evaluating treatment is a well-known problem in IgG4-RD due to the absence of an established assessment system. There are difficulties in defining the severity of the disease, which is why treatment is primarily based on its clinical manifestations. We present a case report of localized IgG4-RD with ulcerative and proliferative manifestations on the tongue, which clinically mimicked oral squamous cell carcinoma. A tumor-like lesion on the tongue can indicate something else other than the malignant or reactive changes commonly found in the oral mucosa. Multiple differential diagnoses of these atypical oral lesions, including localized IgG4-RD, should be considered.

Primary Immunoglobulin G4-Related Laryngeal Disease: A Case Series and Review of Literature

Objective:

Immunoglobulin G4-related disease (IgG4-RD) is an increasingly recognised cause of various systemic fibro-inflammatory conditions. However, laryngeal involvement as a primary feature is extremely rare. We aimed to report on a case series of such patients and examine the global literature relating to laryngeal involvement.

Methods:

Having previously reported a case of IgG4-RD laryngeal pseudotumour, we describe a case series of further 4 patients with primary laryngeal IgG4-RD managed by our UK quaternary airway service and provide a brief overview of laryngeal IgG4-RD.

Results:

Including our cases, 14 cases of primary laryngeal IgG4-RD have been reported. Vocal cord involvement is relatively uncommon. Repeat biopsies may be required to achieve histological diagnosis. Remission is achievable by commencement of immunomodulatory treatment, following which laryngeal reconstruction may be necessary.

Conclusion:

Laryngeal involvement is a rare presentation of IgG4-RD, itself a rare and difficult-to-diagnose condition. A high and prolonged index of suspicion is necessary from both surgical and pathological specialists for correct diagnosis and management.

Multimodality imaging manifestations of Rosai-Dorfman disease

Background

Rosai-Dorfman disease (RDD) is a rare lympho-histiocytic disorder of indeterminate etiology usually presenting with lymph node involvement, and infrequently with extra-nodal manifestations. The diagnosis of this condition is challenging due to the wide spectrum of disease manifestations.

Purpose

To elucidate the radiologic features of this disease using multimodality imaging in histopathologically proven cases and to identify characteristic features that would enable its differentiation from its mimics.

Material and Methods

We retrospectively evaluated imaging studies of 19 patients with histopathologically confirmed RDD presenting to our institute between January 2004 and March 2016. Imaging modalities included magnetic resonance imaging (MRI), computed tomography, FDG-positron emission tomography (PET) CT, mammography, and ultrasonography.

Results

Lymphadenopathy was the most common imaging feature in our study, seen in 11 (57.8%) cases followed by sino-nasal involvement in 7 (36.8%) cases and intracranial masses in 5 (26.3%) cases. Bilateral homogeneously enhancing cervical lymphadenopathy with avidity on FDG-PET scans was the predominant abnormality on imaging. Sino-nasal involvement manifested as homogeneously enhancing soft-tissue masses occupying the paranasal sinuses. Intracranial disease manifested as sellar/suprasellar masses, dural-based lesions along the cerebral hemispheres and choroid plexus enlargement. Unusual disease manifestations included spinal, osseous, and breast lesions.

Conclusion

Due to the high likelihood of multifocal involvement, the recognition of RDD at one site necessitates screening of other sites for disease. Homogeneously enhancing, FDG-avid lymphadenopathy and sino-nasal masses in association with hypointense extra-nodal lesions on T2-weighted MRI are imaging features which could aid the diagnosis of RDD and facilitate its differentiation from pathologies that present in a similar manner.

Malignancies in Patients with IgG4-Related Diseases in Head and Neck Regions

Immunoglobulin G4-related disease (IgG4-RD) is a recently recognized disease, characterized by high serum IgG4 concentrations and IgG4-producing plasma cell expansion with fibrotic or sclerotic changes in affected organs. Recent work has focused on the relationship between IgG4-RD and malignancies, but there is no report of malignancies associated with IgG4-RD in head and neck regions. The aim of this study was to analyze the clinicopathological characteristics of malignancies in patients with IgG4-RD in head and neck regions. We retrospectively analyzed 26 patients with IgG4-RD (12 men and 14 women aged 60.6 ± 11.6 years). The mean follow-up period was 26.6 months (from 12 to 96 months). These patients were divided into single-lesion group (n = 12) with IgG4-RD only in head and neck regions and multiple-lesion group (n = 14) with IgG4-RD in other regions. There was no significant difference in serum IgG4 concentrations between the single-lesion group (459.4 ± 336.4 mg/dL) and the multiple-lesion group (908.0 ± 739.2 mg/dL) (P = 0.07), whereas the IgG4/IgG ratio was significantly lower in the single-lesion group (22.8 ± 11.0%; n = 11) compared with the multiple-lesion group (31.7 ± 15.0%; n = 11, P = 0.02). Among the 26 patients, two patients (7.7%), both in the multiple-lesion group, developed life-threatening malignancies (salivary duct carcinoma in the submandibular gland and lymphoma in the orbital tissue). All physicians need to keep in mind the possible coexistence of malignancies in patients with IgG4-RD with high IgG4/IgG ratio and multiple lesions at the time of diagnosis.

IgG4-related disease presenting as a submucosal tumor of the stomach resected with laparoscopic endoscopic cooperative surgery: a case report

Background

IgG4-related disease (IgG4-RD) is an immune-mediated disorder in which abundant IgG4-positive plasma cells infiltrate affected organs. There have been reported four cases of probable IgG4-RD presenting as a submucosal tumor of the stomach. We herein report the first case of definite IgG4-RD presenting as a submucosal tumor of the stomach resected with laparoscopic endoscopic cooperative surgery (LECS).

Case presentation

A 70-year-old woman with a 6-year history of autoimmune pancreatitis was referred to our department because a 15-mm submucosal tumor in the greater curvature of the lower part of the stomach had been identified via upper gastrointestinal endoscopy. Endoscopic ultrasonography showed a 10-mm low-echoic lesion derived from the submucosal layer of the stomach. A fine-needle aspiration biopsy was attempted, but the tumor was too hard for sampling. F-fluorodeoxyglucose (FDG) positron emission tomography showed an FDG uptake, suggesting a possibility of malignant disease. As the diagnosis could not be confirmed, LECS for both the diagnosis and curative treatment was performed. A histopathological examination showed a tumor with IgG4-positive lymphoplasmacytic infiltration and fibrosis. The ratio of IgG4+/IgG+ lymphoplasmacytic cells was > 80%. A laboratory examination showed elevation of the serum IgG4 levels preoperatively. Thus, the final diagnosis was IgG4-RD of the stomach. No recurrence was observed within 1 year after surgery.

Conclusions

We encountered a case of definite IgG4-RD presenting as a gastric SMT in which a correct diagnosis was achieved by a minimally invasive LECS technique. IgG4-RD may present as a gastric lesion and should be taken into consideration as a differential diagnosis.

Sclerosing sialadenitis of the submandibular gland is rarely an immunoglobulin G4-related disease in the Finnish population

Chronic sclerosing sialadenitis may represent one of many manifestations of an immunoglobulin G4-related disease. However, existing studies typically consist of small patient cohorts rarely conducted in Western populations. The clinical behavior of chronic sclerosing sialadenitis, including follow-up data, warrants further study. Thus, we aimed to determine whether chronic sclerosing sialadenitis always presents as IgG4-related disease or associates with autoimmune diseases and to determine which additional examinations patients may require. Between 2000 and 2017, 51 patients undergoing submandibular gland resection within the Helsinki University Hospital area were diagnosed with chronic sclerosing sialadenitis. We re-evaluated all specimens and performed immunostaining for IgG4. IgG and CD31 stainings were performed for IgG4-positive specimens. IgG4-related disease diagnosis was defined by the Boston consensus statement criteria. We revised clinical data, distributing a follow-up questionnaire to patients to register symptoms of IgG4-related disease or autoimmune disease during follow-up. The chronic sclerosing sialadenitis criteria were fulfilled in 34 patients, whereby 17 were diagnosed as non-sclerosing chronic sialadenitis. In 19 cases, a sialolith associated with a salivary gland lesion. In total, 12 of 51 cases were recognized as IgG4-positive, while two met the criteria for IgG4-related disease. These two cases belonged to the non-sclerosing chronic sialadenitis group, and both involved other organs. The histopathological features between chronic sclerosing sialadenitis and non-sclerosing chronic sialadenitis overlapped regarding the degree of fibrosis and inflammatory infiltrates. In the Finnish population, chronic sclerosing sialadenitis of the submandibular gland does not appear to present as IgG4-related disease. Non-sclerosing chronic sialadenitis can associate with IgG4-related disease. A histopathological distinction between chronic sclerosing sialadenitis and non-sclerosing chronic sialadenitis is not always unequivocal and the presence of a sialolith does not exclude IgG4-positivity. Therefore, immunostaining for IgG4 should be performed when dense plasma cell infiltration is present in either non-sclerosing chronic sialadenitis or chronic sclerosing sialadenitis.

Review of IgG4-related disease

IgG4-related disease is a fibrous-inflammatory process related to immunomodulation. The most commonly affected organs are: the pancreas, bile duct, major salivary glands, lacrimal glands, retroperitoneum and lymphatic ducts. In recent decades, this disease has been recognised as a systemic disorder that includes many single organ disorders, previously unrelated and known as independent entities. The common characteristics shared by the different entities that make up the IgG4-related disease are: raised serum IgG4 levels, alterations in the imaging tests with neoplastic-like swelling of the affected organs, specific histopathological characteristics and in immunostaining, as well as good response to treatment with glucocorticoids. In this work, we will review this pathology with a special emphasis on the characteristics of autoimmune pancreatitis, sclerosing cholangitis related to IgG4 and the involvement of the retroperitoneum, mesenterium and the digestive tract.

IgG4-related disease with pseudotumor formation in the larynx

Mikulicz's disease, an immunoglobulin G4-related disease (IgG4-RD) occurs frequently in the head and neck region but rarely in the larynx. We report a case of IgG4-RD with pseudotumor formation in the larynx. A 50-year-old man presented at our facility for a complete physical examination and diagnostic testing of a left arytenoid tumor. On examination, a large supraglottic mass was noted with signs of dyspnea. Movement disorder of the vocal fold was absent. The patient underwent surgery with general anesthesia to improve respiratory symptoms and a resected specimen was submitted for diagnosis. The pathology findings revealed lymph follicle formation, interstitial follicular fibrosis, angiogenesis, and inflammatory cell infiltration with plasmacytosis. Immunohistologic staining at high magnification revealed one hundred or more IgG4-positive plasma cells and fifty percent IgG4/IgG. In addition, obliterative phlebitis was observed. Medical history was positive for retroperitoneal fibrosis with serum IgG4 levels below the diagnostic criteria of IgG4-RD, but histological characteristics of IgG4-RD were met. The diagnosis of IgG4-RD was established, oral treatment with prednisolone (0.6 mg/kg/day) was initiated, and the tumor reduced in size. IgG4-RD may cause irreversible functional impairment. Early diagnosis and treatment are important in reducing the risk of permanent impairment of vocal fold mobility.

Immunoglobulin G4-related Disease: Presentation of the First Case with Isolated Pterygopalatine Fossa Involvement

Immunoglobulin G4-related disease is an immune-mediated fibroinflammatory disease with single or multiple organ involvement. Clinically it mimics several benign and malignant tumors, as well as infectious, and inflammatory disorders. It typically presents as multiple tumor-forming lesions. Histological and immunohistochemical findings are characteristic. Serum immunoglobulin G4 levels are usually increased. Systemic corticosteroid administration is the treatment of choice with good response, especially in early disease stages. We present the first case of immunoglobulin G4-related disease presenting as an isolated tumor forming lesion of the left pterygopalatine fossa. Imaging studies indicated a benign process. Histological findings were consistent with IgG4-related disease. The patient showed a good response to systemic corticosteroid treatment and remains free of symptoms 18 months following diagnosis.

New causes of hypophysitis

Hypophysitis is a rare entity characterized by inflammation of the pituitary gland and its stalk that can cause hypopituitarism and/or mass effect. Etiology can be categorized as primary or secondary to systemic disease, but may also be classified according to anatomical and hispathological criteria. Newly recognized causes of hypophysits have been described, mainly secondary to immunomodulatory medications and IgG4-related disease. Diagnosis is based on clinical, laboratory and imaging data, whereas pituitary biopsy, though rarely indicated, may provide a definitive histological diagnosis. For the clinician, obtaining a broad clinical and drug history, and performing a thorough physical examination is essential. Management of hypophysitis includes hormone replacement therapy if hypopituitarism is present and control of the consequences of the inflammatory pituitary mass (e.g. compression of the optic chiasm) using high-dose glucocorticoids, whereas pituitary surgery is reserved for those unresponsive to medical therapy and/or have progressive disease. However, there remains an unmet need for controlled studies to inform clinical practice.

Temporal bone involvement of IgG4-related disease: a rare condition misleading to petrous apicitis causing lateral rectus palsy

IgG4-related disease (IgG4-RD) of temporal bone is rare and clinical manifestation mimics infection. A 19-year-old female presented with progressive left earache and intermittent left nasal obstruction. Then, she rapidly developed left lateral rectus palsy. The physical examination revealed mild redness of left tympanic membrane and a small nasal polyp from the left middle meatus. CT scan showed left petrous apicitis and enhancing sinonasal mucosa. Therefore, Gradenigo's syndrome was first considered. The empirical intravenous antibiotic was immediately prescribed and surgery was performed. The intraoperative pale soft tissue mass in middle ear and polyp in the left nasal cavity were sent for pathological examination and found positive immunohistochemical stains for IgG4 in plasma cells. Systemic corticosteroid, the first-line treatment, was started and her symptoms were finally recovery.

IgG4-related disease in the head and neck

PURPOSE OF REVIEW

To summarize current evidence regarding the pathophysiology, diagnostic criteria, and management of IgG4 disease in the head and neck.

RECENT FINDINGS

The anti-CD20 antibody, rituximab is being used increasingly as a primary treatment modality in cases with a definitive diagnosis. Despite the favorable prognosis, it is now recognized that the incidence of cancer development within 3 years of diagnosis is higher than that of the general population.

SUMMARY

IgG4-related disease is a sclerosing, chronic inflammatory disease, that is benign, and usually occurs in middle-aged to elderly individuals. Definitive diagnosis of IgG4-related disease requires radiological confirmation of enlargement of the affected organ, elevated serum IgG4 levels, and characteristic histopathological findings. Treatment is primarily with systemic corticosteroids or the monoclonal anti-CD20 antibody rituximab, surgical excision, or a combination of treatment modalities. Prognosis is good with complete remission in up to 90% of patients.

IgG4-related dacryocystitis and aortitis: A new association

A 73-year-old woman with a history of muscular weakness and dyspnoea of unknown etiology was referred to our Ophthalmology Department for dacryocystitis. Lacrimal sac biopsy revealed IgG4 plasma cell infiltration and systemic diagnosis was done based on this, allowing an appropriate treatment to be established. To our knowledge, this is the first reported case of IgG4-related dacryocystitis associated to aortitis.

IgG4-Related Disease Presenting as Cervical Lymphadenopathy

Cervical lymph node enlargement as the first and sole manifestation of IgG4-related disease (IgG4-RD) is rare and is often difficult to distinguish from lymphoma. Here, we report a case of a 63-year-old man initially presenting with bilateral posterior neck masses. Ultrasonography revealed multiple matted, ovoid, homogenous, hypoechoic, and enlarged lymph nodes below the right parotid gland. In addition, there was heterogeneous echotexture with small and indistinct hypoechoic nodules over bilateral parotid and submandibular glands which suggested sclerosing sialadenitis. Pathology of the tissues obtained by core needle biopsy revealed reactive hyperplasia, but a diagnosis of lymphoma could not be excluded. Subsequently, excisional biopsy and serological tests were done. The diagnosis of IgG4-RD was confirmed due to marked elevation of serum IgG4 levels and pathological evidence of IgG+ and IgG4+ plasma cell infiltration in the lymph node specimen. The patient's neck masses subsided gradually after 1 week of oral steroid therapy. The differential diagnosis of IgG4-RD should always be considered when sclerosing sialadenitis is presented with cervical lymphadenopathy.

Eosinophilic angiocentric fibrosis : a sino-orbital masquerader

A 58-year-old Caucasian male presented with left periorbital oedema extending to the nasal area for 1 year along with nasal discharge for 1 month. Lab work was significant for positive cytoplasmic antineutrophil cytoplasmic antibodies. CT scan showed solid mass along the nasal soft tissue with bony nasal destruction. A CT scan of the thorax was performed to rule out granulomatosis with polyangiitis and showed multiple pulmonary nodules. Biopsies of the nasal mass and lung nodule were performed which showed fragments of fibrosis with spindle cell proliferation consistent with eosinophilic angiocentric fibrosis (EAF). EAF is a very rare disease, recently described as a subtype of immunoglobulin G4-related disease. A few rare cases of EAF involving the structures of the orbit have been reported in the literature.

IgG4 disease of the ear: Report and review

In recent years, an immune-mediated disorder involving IgG4 has been described, which targets multiple organs and explains a number of disorders previously regarded as “idiopathic” or of unknown origin. Furthermore, the discovery of IgG4-related disease (IgG4-RD) has placed a number of pathologies within its spectrum, linking symptoms and conditions formerly considered isolated. Reports of the manifestations of IgG4-RD in the head and neck are scarce. Otological manifestations have been reported, but only a handful of cases are available in the literature. This is the first report of recalcitrant serous otitis media secondary to IgG4-RD, confirmed by immunohistopathology. A case of IgG4-RD of the middle ear is presented, manifesting itself as recalcitrant serous otitis media. The case is presented from an otolaryngological and histopathological perspective and briefly reviews this rare disorder. The importance of the awareness of IgG4-RD resides mainly in the fact that it is a treatable condition. This can potentially improve the quality of life of a number of patients, some of whom may not have had a clear diagnosis. A favorable response to glucocorticoids has been reported. In cases of persistent symptoms, immunosuppressive therapy has been used with success.

Ear and Temporal Bone Pathology: Neural, Sclerosing and Myofibroblastic Lesions

Neural, sclerosing, and myofibroblastic lesions of the ear and temporal bone present diagnostic challenges for both clinicians and pathologists due to significant overlap in their clinical presentations, histologic appearances, and immunohistochemical profiles. While some of these lesions, such as schwannomas, are relatively common, others are rendered even more difficult because they are encountered very rarely in routine surgical pathology practice. This review is intended to provide an update on the pathology of some of the most commonly encountered primary diagnostic entities for the ear and temporal bone, and includes the following neural lesions: schwannoma, meningioma, and encephalocele/meningocele. Sclerosing lesions that will be discussed include spindle cell and sclerosing rhabdomyosarcoma, sclerosing epithelioid fibrosarcoma, and sclerosing paraganglioma. Finally, myofibroblastic lesions that will be reviewed are nodular fasciitis, IgG4-related disease, and solitary fibrous tumor. For each of these lesions, the differential diagnosis and useful ancillary tests will be discussed in the context of a broad range of additional primary and secondary lesions.

IgG4-related disease: association between chronic rhino-sinusitis and systemic symptoms

PURPOSE

The objective of this study is to analyze the relationship between chronic rhino-sinusitis (CRS) and systemic symptoms in patients with IgG4-related disease (IgG4-RD).

PATIENTS AND METHODS

The patients with IgG4-RD, confirmed by restrict association with clinical and histopathological manifestations between March 2013 and July 2016, were enrolled and followed-up for 1 year at the Tongren Hospital, Capital Medical University. The patients were divided into two groups: the case group included IgG4-RD patients with CRS confirmed by clinical and imaging, while the control group included IgG4-RD patients without CRS confirmed by clinical and imaging. Age, gender, clinical manifestations, the percentage of eosinophils in peripheral blood, sedimentation (ESR), C-reaction protein, serum IgE and IgG4 levels, histopathology, and treatment drugs at the baseline and 1 year of follow-up were compared between the two groups.

RESULTS

A total of 46 cases met the diagnostic criteria for IgG4-RD. A total of 30 patients (65.2%) had IgG4-RD complicated with CRS, and were aged 49.7 ± 13.4 years, with male:female ratio = 2:1. The disease duration in the case group was longer than that in the control group (3.0 versus 0.8, p = 0.009). The ratio of ocular involvement was higher (86.7 versus 60%, p < 0.001), and allergic manifestations including drug allergy, asthma, and allergic skin were more common (56.5 versus 20%, p = 0.004), with a higher percentage of eosinophils in peripheral blood (8.5 versus 3.3%, p = 0.018) and more sensitive to glucocorticoids (6.0 versus 3.5, p = 0.004) than those in the control group.

CONCLUSIONS

CRS in patients with IgG4-RD was closely associated with IgG4-related ocular lesions, which was more prone to allergic manifestations accompanied by raised percentage of eosinophils in peripheral blood. The treatment of patients with IgG4-RD complicated with CRS was more effective than those with IgG4-RD without CRS.

The Clinicopathologic Spectrum of IgG4-Related Disease

Immunoglobulin G4-related disease is a fibroinflammatory systemic disease that is characterized by focal or diffuse organ infiltration by immunoglobulin G4-bearing plasma cells. Immunoglobulin G4-related disease may affect any organ, and a high index of suspicion is necessary for early detection to avoid irreversible fibrosis, organ dysfunction, and death. Tumor-forming lesions are common radiological features of immunoglobulin G4-related disease that need to be differentiated from malignancies. The diagnostic approach requires the integration of clinical, biochemical, and radiographic manifestations with classic histopathologic features, which remain crucial to diagnosis. The histology of immunoglobulin G4-related disease is determined by a dense lymphoplasmacytic infiltrate, storiform fibrosis, and obliterative phlebitis in the presence of increased immunoglobulin G4-positve plasma cells. Although immunoglobulin G4-related disease forms a distinct, clinically independent disease category, many questions and problems remain unanswered, especially on its pathogenesis and the role of immunoglobulin G4. Advances in the understanding of immunoglobulin G4-related disease are likely to change the diagnostic approach in the future and create potential targets for therapeutic purposes. Here we describe the concept of immunoglobulin G4-related disease and the most recent knowledge in the clinico-pathological characteristics on this emerging disease. This study can guide clinicians in early diagnosis and prevent unnecessary surgical resections.