IgG4-related inflammatory pseudotumor of the trigeminal nerve: another component of IgG4-related sclerosing disease?

A unique presentation of IgG4 disease with ocular, neurologic and mastoid involvement

A man in his 20s presented with headache and acute deterioration in visual acuity. He was found to have panuveitis and raised intracranial pressure with papilloedema. MRI and F-fluorodeoxyglucose positron emission tomography confirmed a subclinical, but active, inflammatory mastoid process. Histology of the mastoid showed immunoglobulin G4 (IgG4) cells, plasma cells and storiform fibrosis.This presentation of IgG4 disease has not been previously described.Treatment with high-dose steroids was initiated, followed by long-term immunosuppressive therapy. The patient's symptoms improved, although he remains dependent on azathioprine and low dose oral steroids for symptom control. To date, there has been no progression of the disease.

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.

IgG4-Related Disease of the Skull and Skull Base-A Systematic Review and Report of Two Cases

OBJECTIVE

IgG4-related disease (IgG4-RD) is an inflammatory process that uncommonly can present in the skull base and calvarium and mimic a tumor but the nature of this condition is not well summarized in the neurosurgical literature.

METHODS

A review was performed of 2 cases of IgG4-RD in the skull base highlighting the diagnostic challenges with assessment of these skull base lesions, and a systematic review of relevant literature was carried out.

RESULTS

A systematic review of the literature conducted in accordance with PRISMA guidelines identified 113 articles, with 184 cases of IgG4-RD in the skull base or calvarium. The most commonly affected locations include the meninges, cavernous sinus, base of the posterior fossa, clivus, and mastoid bone. Headache, visual and auditory disturbances, cranial nerve dysfunction, and seizures were the most common presenting symptoms. Medical treatment was highly successful and most commonly consisted of corticosteroids coadministered with immunosuppressive agents such as rituximab. Prevalence seemed to be equal between sexes, and serum IgG4 levels were increased in 61% of patients. Delayed diagnosis and a need for multiple biopsies were reported in numerous cases. Two cases of skull base IgG4-RD from the authors' institution show the variable presentations of this disease. More invasive surgical biopsies were required in both cases, and corticosteroid treatment led to significant clinical improvement.

CONCLUSIONS

IgG4-RD is an uncommon condition with an increasing body of reported cases that can affect the skull base and calvarium and should be in the differential diagnosis, because delay in diagnosis and treatment may be common.

IgG4-Related Inflammatory Pseudotumor Involving the Clivus: A Case Report and Literature Review

IgG4-related inflammatory pseudotumors are very uncommon and are characterized histologically by the presence of inflammatory swellings with increasing IgG4-positive plasma cells and lymphocytes infiltrating the tissues. As reports of intracranial IgG4-related pseudotumors are very rare, we report a case of an IgG4-related inflammatory pseudotumor involving the clivus mimicking meningioma. A 46-year-old male presented with intermittent headache for 2 years and a sudden onset of dysphagia and dysphonia of 7 days' duration along with lower limb weakness. Enhanced magnetic resonance imaging (MRI) of the skull base revealed an isointense signal on T1- and T2-weighted images from an enhanced mass located at the middle of the upper clivus region, for which a meningioma was highly suspected. Then, an endoscopic transsphenoidal approach was adopted and the lesion was partially resected, as the subdural extra-axial lesion was found to be very tough and firm, exhibiting fibrous scarring attaching to the brain stem and basal artery. After the surgery, brain stem and posterior cranial nerve decompression was achieved, and the patient's symptoms, such as dysphagia, dysphonia and lower limb weakness, improved. Pathological findings showed many IgG4-positive plasma cells and lymphocytes surrounded by collagen-rich fibers. The patient was sent to the rheumatology department for further glucocorticoids after the diagnosis of an IgG4-related inflammatory pseudotumor was made. This case highlights the importance of considering IgG4-related inflammatory pseudotumors as a differential diagnosis in patients with lesions involving the clivus presenting with a sudden onset of symptoms of dysphagia and dysphonia along with lower limb weakness when other more threatening causes have been excluded. IgG4-related inflammatory pseudotumors are etiologically enigmatic and unpredictable, and total resection might not be warranted. Glucocorticoids are usually the first line of treatment after diagnosis.

IgG4-Related Disease in the Frontal Convexity Concomitant with Smoldering Multiple Myeloma: A Case Report and Review of the Literature Regarding Therapeutic Implications

BACKGROUND

We have reported an extremely rare case of a frontal convexity tumor diagnosed as IgG4-related disease (IgG4-RD) with unique neuroradiological images.

CASE DESCRIPTION

A 64-year-old man with a history of monoclonal gammopathy of undetermined significance and conservative treatment had presented with a left facial spasm. Computed tomography showed a high-density round tumor with perifocal edema in the right frontal convexity. Magnetic resonance imaging demonstrated unique findings, including low signal intensity on T1- and T2-weighted, fluid-attenuated inversion recovery, and diffusion-weighted images, with slight gadolinium enhancement. The tumor was totally removed via right frontal craniotomy. It had been located in the subdural space, was not adherent to the dura, and was less vascular than meningiomas. Histological investigation demonstrated plasma cells that were strongly positive for IgG4 and contained κ and λ light chains at a ratio of 1.5:1. The serum IgG4 level was elevated. The tumor met the diagnostic criteria for IgG4-RD. The patient was followed up for 3 years during postoperative adjuvant steroid therapy. The steroid therapy was discontinued, and during the next 4 years, neither tumor recurrence nor symptoms were observed.

CONCLUSION

Intracranial IgG4-RD with smoldering monoclonal gammopathy of undetermined significance is extremely rare. We reviewed the differential diagnosis of plasma cell granuloma and plasmacytoma, therapeutic implications, and clinical outcomes. Complete resection of a conspicuous and solitary IgG4-RD lesion in the frontal convexity is simple and could provide a cure with less-aggressive adjuvant therapy.

Intracranial Multiple Pseudotumor Due to Immunoglobulin G4-Related Disease without Other Lesions: Case Report and Literature Review

BACKGROUND

Immunoglobulin (Ig)G4-related disease (IgG4-RD) was defined only recently and can be found in many organs. As intracranial lesions, hypophysitis and pachymeningitis are well known, whereas intracranial pseudotumor is unusual. This case involved multiple intracranial pseudotumors without extracranial lesions, mimicking multiple meningioma.

CASE DESCRIPTION

A 72-year-old woman was referred to our hospital with an incidental mass lesion at the craniocervical junction on magnetic resonance imaging (MRI). MRI showed diffuse enhanced extra-axial nodules around the medulla and middle cranial fossa. Surgery was performed for the gradually enlarging tumor. Intraoperative findings showed hard nodules around the vertebral artery. We performed subtotal resection. Neuropathological findings showed diffuse lymphoplasmacytic infiltration with lymphoid follicles. Immunohistochemical studies for IgG4 and IgG showed the histological criteria for IgG4-RD were met. Given the high IgG4 serum level, we diagnosed IgG4-RD. Steroid was administered initially but was then tapered, and nodules have since remained small.

CONCLUSIONS

This case demonstrates IgG4-RD mimicking meningioma with multiple masses but without extracranial lesions. This case and previous descriptions suggest the possibility of pseudotumor due to IgG4-RD in the presence of multiple extra-axial lesions at the dura and supplying artery, hard nodules with thickening of the artery, and frozen section findings of lymphoplasmacytes surrounded by rich collagen fibers. In such cases, the pseudotumor due to IgG4-RD should be resected, and total resection might not be warranted.

CT and MR imaging of orbital inflammation

PURPOSE

Orbital inflammation can be idiopathic or in the context of a specific disease and it can involve different anatomical orbital structures. On imaging, inflammatory disease is frequently mistaken for infection and malignant tumors, and its underlying cause is often not determined. Through this article we aim to improve orbital inflammation diagnosis and underlying inflammatory diseases recognition.

METHODS

The imaging protocols and characteristics of orbital inflammation were reviewed.

RESULTS

A decision tree for the evaluation of these patients is provided. First, a combination of clinical and radiological clues is used to recognize inflammation, in particular to differentiate it both from orbital infection and tumor. Subsequently, different radiological patterns are recognized, often allowing the differentiation of the several orbital inflammatory diseases.

CONCLUSION

The use of adequate imaging protocols and subsequent evaluation allow the recognition of an orbital lesion as inflammatory and the diagnosis of the underlying inflammatory disease. All in all, a proper treatment can be established, and at times, a biopsy can be avoided.

Clivus Inflammatory Pseudotumor Associated with Immunoglobulin G4-Related Disease

BACKGROUND

Immunoglobulin G4 (IgG4)-related disease is a more recently recognized syndrome. It is characterized by increasing IgG4-positive plasma cells and lymphocyte infiltration. Reports of intracranial pseudotumors associated with IgG4-related disease are very rare. We report a rare case of clivus pseudotumor associated with IgG4-related disease mimicking meningioma.

CASE DESCRIPTION

A 50-year-old man presented with abducens paralysis of the right eye. Brain magnetic resonance imaging revealed a uniformly enhanced mass located in the right upper clivus area, and meningioma was highly suspected. The tumor was totally resected via a retrosigmoid approach craniotomy, which achieved sufficient decompression of the right abducens nerve. Postoperative pathology revealed IgG4-related disease with IgG4 strongly positive on immunohistochemical staining. The patient had no history of autoimmune disease. Postoperative laboratory data revealed no elevation of either IgG (6.94 g/L) or IgG4 (0.131 g/L). Follow-up contrast MRI showed the lesion had disappeared.

CONCLUSIONS

Although several cases of intrasellar hypophysitis have been reported, reports of intracranial pseudotumors associated with IgG4-related disease are rare. Special attention is required when the differential diagnosis includes meningioma. Preoperative diagnosis is very important because inflammatory pseudotumors associated with IgG4-related disease could be treated with steroid therapy, avoiding surgery.

Infrequent organ involvement of IgG4-related diseases: a literature review

IgG4-related disease (IgG4-RD) is a chronic and systemic disease that can involve multiple organs. The most commonly involved organs include the salivary glands, orbital adnexal structures, paranasal sinus, thyroid, lungs, breasts, aorta, pancreas, biliary ducts, kidneys, retroperitoneum, lymph nodes, prostate, pituitary, and endocranium. Due to increased disease research, several new site-specific nuances of IgG4-RD have been described. The authors have reviewed the recent literature and briefly summarize the infrequent organ involvement of IgG4-RD.

IgG4-Related Disease: A New Etiology Underlying Diffuse Intracranial Dilating Vasculopathy

BACKGROUND

Diffuse intracranial aneurysmal vasculopathy is a rare condition, previously described in patients with human immunodeficiency virus infection. IgG4-related disease (IgG4-RD) is a recognized inflammatory disease of systemic organs, leading to fibrosis of connective tissues. It also has been linked to inflammatory dilating aortic aneurysms, coronary vascular disease, hypophysitis, orbital pseudotumor, and pachymeningitis. It has not yet been described as a cause of diffuse intracranial dilating vasculopathy. Histologically, this disease is characterized by IgG4-plasma cell infiltration, fibrosis, and phlebitis.

CASE DESCRIPTION

A 40-year-old woman presented with acute heart failure, valvular insufficiency, and mycotic coronary aneurysms, concerning for endocarditis. Infectious workup was negative. Concurrent neurovascular workup revealed intracranial aneurysms, appearing mycotic in origin. Despite aggressive treatment for more than 5 years, she suffered multiple episodes of subarachnoid hemorrhage from a progressive dilating intracranial vasculopathy. Serum IgG levels and aneurysm wall pathology were consistent with IgG4-RD.

CONCLUSIONS

This is the first reported case of a diffuse intracranial dilating vasculopathy secondary to IgG4-RD. Recognition of similar pathologic findings in clinical presentation and radiologic workup should prompt further rheumatologic workup and possible immunosuppressive therapies.

Imaging of IgG4-related disease of the head and neck

IgG4-related disease is a systemic, inflammatory disorder typically involving multiple organ systems. Several eponymous conditions described previously in the clinical and radiology literature are now recognised to be part of the IgG4-related disease spectrum. This includes multiple manifestations in the head and neck region, which are the subject of this review. Imaging can occasionally suggest the specific diagnosis of IgG4 disease. More commonly, it will be included in a limited differential diagnosis that requires clarification with the aid of image-guided biopsy. There are strict histopathological criteria for the diagnosis of IgG4-related disease.

Inflammatory Pseudotumor of the Infraorbital Nerve: A Rare Diagnosis to Be Aware of

Inflammatory pseudotumor (IPT) is a rare benign mass-forming disease that can arise anywhere throughout the body, mimicking a wide spectrum of other conditions. Its diagnosis can be challenging, especially when it involves uncommon sites. The authors report a patient of an atypical localization of IPT, occurred as an enlarging bulk in the infraorbital nerve channel in a patient who presented with facial numbness. Clinical and radiological aspects similar to schwannoma led to misdiagnosis and over-treatment. The differential diagnosis of an infraorbital mass should include IPT and the least invasive treatment should be preferred, as steroid therapy being the first-line treatment for IPT.

Neurological Manifestations of IgG4-Related Disease

OPINION STATEMENT

IgG4-related disease (IgG4-RD) is a multisystem inflammatory disorder. Early recognition of IgG4-RD is important to avoid permanent organ dysfunction and disability. Neurological involvement by IgG4-RD is relatively uncommon, but well recognised-hypertrophic pachymeningitis and hypophysitis are the most frequent manifestations. Although the nervous system may be involved in isolation, this more frequently occurs in conjunction with involvement of other systems. Elevated circulating levels of IgG4 are suggestive of the condition, but these are not pathognomonic and exclusion of other inflammatory disorders including vasculitis is required. Wherever possible, a tissue diagnosis should be established. The characteristic histopathological changes include a lymphoplasmacytoid infiltrate, storiform fibrosis and obliterative phlebitis. IgG4-RD typically responds well to treatment with glucocorticoids, although relapse is relatively common and treatment with a steroid-sparing agent or rituximab may be required. Improved understanding of the pathogenesis of IgG4-RD is likely to lead to the development of more specific disease treatments in the future.

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.

Orbital Involvement and Ocular Surface Changes in IgG4-Related Systemic Disease

PURPOSE

To evaluate ophthalmic involvement of systemic immunoglobulin-G4-related disease (IgG4-RD) and describe the changes in both ocular surface parameters and corneal subbasal nerve plexus.

MATERIALS AND METHODS

Twenty eyes of 10 patients with systemic IgG4-RD and 20 eyes of 10 control subjects were enrolled in this study. Demographic information, medical history, serum IgG4 levels, orbital imaging, and follow-up data of subjects were recorded. Ocular surface tests were carried out in the order of tear break-up time (BUT), lissamine green (LG) staining, Schirmer I test with anesthesia, and ocular surface disease index (OSDI) questionnaire for all participants. Corneal subbasal nerves and basal epithelial cell layer were evaluated using in vivo confocal microscopy.

RESULTS

Among the 10 patients with IgG4-RD, 11 eyes of 7 patients had orbital involvement. Among these 7 patients with IgG4-related ophthalmic disease, 4 presented with painless eyelid or periorbital swelling, 2 with diplopia and restricted ocular motility, and 1 with proptosis. Patients with IgG4-RD had higher OSDI (5.9 ± 6.6 vs. 1.7 ± 2.4, P < 0.001) and LG staining scores (0.7 ± 1.0 vs. 0.0 ± 0.0, P = 0.011) and lower BUT (5.6 ± 1.4 vs. 10.2 ± 1.0, P < 0.001) and Schirmer values (11.9 ± 10.3 vs. 18.3 ± 4.4, P = 0.021) as compared with those of control subjects. Total nerve density and nerve fiber length were found to be significantly lower in patients with IgG4-RD.

CONCLUSIONS

The orbit is frequently involved during the course of IgG4-RD. These patients should be evaluated in terms of ocular surface disease and dry eye, which may be associated with lacrimal gland and/or orbital nerve involvement.

Infraorbital nerve involvement on magnetic resonance imaging in European patients with IgG4-related ophthalmic disease: a specific sign

OBJECTIVES

To measure the frequency of infraorbital nerve enlargement (IONE) on magnetic resonance imaging (MRI) in European patients suffering from an IgG4-related ophthalmic disease (IgG4-ROD) as compared to patients suffering from non-IgG4-related ophthalmic disease (non-IgG4-ROD).

METHODS

From January 2006 through April 2015, 132 patients were admitted for non-lymphoma, non-thyroid-related orbital inflammation. Thirty-eight had both pre-therapeutic orbital MRI and histopathological IgG4 immunostaining. Fifteen patients were classified as cases of IgG4-ROD and 23 patients as cases of non-IgG4-ROD. Two readers performed blinded analyses of MRI images. The main criterion was the presence of an IONE, defined as the infraorbital nerve diameter being greater than the optic nerve diameter in the coronal section.

RESULTS

IONE was present in 53% (8/15) of IgG4-ROD cases whereas it was never present (0/23) in cases of non-IgG4-ROD (P < 0.0001). IONE was only present in cases where, on MRI, the inflammation of the inferior quadrant was present and in direct contact with the ION canal.

CONCLUSIONS

In European patients suffering from orbital inflammation, the presence of IONE on an MRI is a specific sign of IgG4-ROD. Recognition of this pattern may facilitate the accurate diagnosis for clinicians and allow for the adequate management and appropriate care of their patients.

KEY POINTS

• IONE on an MRI is a specific sign of IgG4-ROD. • IONE recognition allows for a quicker diagnosis and appropriate management. • IONE appears when inflammation is in direct contact with the ION canal.

IgG4-related inflammatory pseudotumor: A systematic review of histopathological features of reported cases

OBJECTIVES

There is marked inconsistency in reporting the key features of IgG4-related inflammatory pseudotumor (IPT) cases. We aimed to analyze the various aspects of IgG4-related IPTs and to test the performance of the consensus criteria for their diagnosis.

METHODS

PubMed database was searched for IgG4-related IPT cases. The data regarding patient demographics, clinical presentation, laboratory findings, histopathological features, and treatment response are extracted and are presented here in a descriptive manner.

RESULTS

The study included 40 papers describing the clinicopathological features of 83 IPTs in 80 patients. Seventeen cases were diagnosed on biopsies; while remaining were diagnosed on excision specimens. Among these, 50 cases were categorized as highly suggestive and 24 cases as probable for IgG4RD; while nine cases had insufficient histopathological evidence of IgG4RD. Two cases diagnosed on biopsies having insufficient evidence of IgG4RD showed partial or no response to steroids; while 12/14 cases (85.71%) diagnosed on biopsies that were histologically suggestive or probable for IgG4RD showed prompt response to steroids.

CONCLUSION

Many reports have not specifically mentioned the full histopathological findings of IgG4-related IPTs that may hinder in refining the diagnostic criteria of IgG4RD. The IgG4-related IPTs diagnosed on biopsies with requisite features showed prompt response to steroids indicating specificity of histopathological findings in predicting treatment response.

Neuromuscular complications in cancer

Cancer is becoming a treatable and even often curable disease. The neuromuscular system can be affected by direct tumor invasion or metastasis, neuroendocrine, metabolic, dysimmune/inflammatory, infections and toxic as well as paraneoplastic conditions. Due to the nature of cancer treatment, which frequently is based on a DNA damaging mechanism, treatment related toxic side effects are frequent and the correct identification of the causative mechanism is necessary to initiate the proper treatment. The peripheral nervous system is conventionally divided into nerve roots, the proximal nerves and plexus, the peripheral nerves (mono- and polyneuropathies), the site of neuromuscular transmission and muscle. This review is based on the anatomic distribution of the peripheral nervous system, divided into cranial nerves (CN), motor neuron (MND), nerve roots, plexus, peripheral nerve, the neuromuscular junction and muscle. The various etiologies of neuromuscular complications - neoplastic, surgical and mechanic, toxic, metabolic, endocrine, and paraneoplastic/immune - are discussed separately for each part of the peripheral nervous system.

Immunoglobulin G4-related disease of the orbital cavity, cervical lymph nodes and greater auricular nerve: case report

IgG4-related disease (IgG4-RD) is a novel clinicopathological entity characterised by elevated tissue levels of IgG4-positive plasma cells. It can present in almost every organ systems. We present a case of a 48year-old man with recurrent intra-orbital and cervical lymph node swelling and found to have greater auricular nerve involvement intraoperatively during open surgical biopsy. Histopathological evaluation of biopsied specimens from these lesions yielded IgG4-positive plasma cell infiltration on immunohistochemistry. Key pathological features such as prominent lymphoplasmacytic population, storiform fibrosis and obliterative phlebitis were also seen. A diagnosis of IgG4-RD was made. Oral prednisone therapy ameliorated the symptoms and patient remained in remission at followup. Literature review indicated that IgG4-RD is a rare condition that seldom occurs concurrently in the orbital cavity, cervical lymph nodes and involving the greater auricular nerve. The condition may often masquerade as malignancy or infection due to formation of tumefactive lesions but tend to respond favourably to glucocorticoid or immunosuppressants. The differential diagnosis of unusual mass lesions in these locations should include IgG4-RD. The otolaryngologist, as well as other health professionals, should be familiar with this novel disease to ensure timely diagnosis and treatment.

A case of refractory IgG4-related peripheral neuropathy with severe axonal damage

A 78-year-old man presented complaining of tingling and pain. Neurological examination revealed dysesthesia and hypothermesthesia below both knees and areflexia in the lower extremities. Laboratory data revealed elevated serum levels of immunoglobulin IgG4 and para-aortic, and mesenteric lymphadenopathy was evident on plain computed tomography of the abdomen. Microscopic findings of a bone marrow biopsy specimen showed occlusion of blood vessels with IgG4-positive plasma cells. IgG4-related disease was diagnosed because the bone marrow biopsy exhibited > 10 IgG4-positive plasma cells per high-power field. Treatment was initiated with prednisolone starting at 30 mg/day, but no improvement in neurological symptoms was achieved. Sural nerve biopsy demonstrated obstructive thromboangiitis with severe loss of myelin and axons. Further investigations are needed to elucidate the relationship between obstructive thromboangiitis and steroid-resistant IgG4-related peripheral neuropathy.

Intracranial spread of IgG4-related disease via skull base foramina

IgG4-related disease (IgG4-RD) is a newly recognised, multiorgan, inflammatory disease, and its full clinical spectrum remains undefined. We present a biopsy-proven case of IgG4-RD presenting with a parapharyngeal mass with intracranial extension and possible involvement of the brain parenchyma. We highlight the importance of considering the diagnosis in those presenting with tumefactive lesions, leptomeningitis or pachymeningitis and emphasise the value of securing a tissue diagnosis so that appropriate long-term treatment can be instigated and complications avoided.

Inflammatory Pseudotumor of the Brain Parenchyma with IgG4 Hypergammaglobulinemia

A 58-year-old woman with a 1-month history of right hand clumsiness and speaking difficulty was admitted to our hospital. A neurological examination revealed sensory aphasia and right hemiparesis. Her laboratory tests showed elevated serum levels of IgG and IgG4, pancytopenia, and liver dysfunction. The results of the imaging studies of her abdomen were compatible with sclerosing cholangitis. Brain MRI showed extensive signal abnormalities in the left hemisphere on T2-weighted and fluid-attenuated inversion recovery (FLAIR) images, extending from left internal capsule to the cerebral peduncle with an irregularly enhancing lesion in the left parietal lobe. A brain biopsy revealed lymphocyte and plasma cell infiltration and reactive gliosis. Most of the plasma cells were IgG positive; however, IgG4-positive plasma cells were sparsely observed. After the initiation of betamethasone treatment, her symptoms and the brain MRI abnormalities showed significant improvement. The brain biopsy results did not meet the current criteria of IgG4-related disease. This is the first reported case of a tumefactive lesion of the brain parenchyma with serum IgG4 elevation, which was responsive to steroid treatment. The accumulation of a greater number of reports on the pathological investigation of cases of possible IgG4-related disease may help to elucidate the exact role of IgG4 in IgG4-related disorders.

Characteristics, diagnosis and therapeutic strategies for IgG4-related orbital disease

Thanks to detailed studies conducted in recent years, a new disease syndrome was identified in 2001. It is known as a IgG4-related disease and its differentiation is based on the analysis of IgG4 levels in the affected tissues. The IgG4-related disease is considered to be a generalized pathological process involving a wide spectrum of various disorders that may affect distant organs. Orbital IgG4-related disease is a recently reported issue that may prove important for the elucidation of the etiology of idiopathic, lymphoplasmacytic or fibrotic disorders of various organs, including the orbits. In this article, we are describing epidemiology and differential diagnostics of IgG4-related orbital disease with particular focus on pseudotumors, MALT lymphomas and lymphocyte/plasma cell infiltrations of the orbit. We are also discussing therapeutic possibilities currently available in the management of the disease.

Immunoglobulin G4-related diseases in the head and neck: a systematic review

BACKGROUND

Immunoglobulin G4 related disease (IgG4-RD) is a poorly understood chronic inflammatory disorder affecting the middle-aged and elderly that can present to the otolaryngologist. We aim to summarize the current literature regarding the manifestations and management of IgG4-RD in the head and neck.

METHODS

Pubmed and EMBASE were searched using the term relevant search algorithm utilizing keywords such as: IgG4 related disease, head and neck, orbit, salivary glands, sialadenitis, Kuttner, angiocentric eosinophilic fibrosis, submandibular, lacrimal, thyroid, dacryoadenitis, nasal, sinus, and Mikulicz's. Reference lists were searched for identification of relevant studies. Case reports, original research and review articles published in English from 1964 to 2014 whose major topic was IgG4-RD affecting the head and neck were included. Data regarding patient demographics, presentation, histopathology, management and treatment outcomes of IgG4-RD were extracted. Level of evidence was also assessed and data were pooled where possible. Three independent reviewers screened eligible studies; extracted relevant data and discrepancies were resolved by consensus, where applicable. Descriptive and comparative statistics were performed.

RESULTS

Fourty-three articles met our inclusion criteria. IgG4-RD most often presents as a mass lesion in the head and neck region. Common diagnostic features include: (1) elevated serum IgG4 level, (2) marked infiltration of exocrine glands by IgG4-positive plasma cells with fibrosis, and (3) marked improvement with corticosteroid therapy and additional immunosuppressive therapy in corticosteroid refractory cases. Early diagnosis and involvement of rheumatology is important in management.

CONCLUSIONS

IgG4-RD is a challenging non-surgical disease that has multiple manifestations in the head and neck. It must be distinguished from various mimics including malignancy, systemic diseases, and infectious. Otolaryngology-Head and Neck surgeons should be aware of this condition and its management.

Intracranial Inflammatory Pseudotumors Associated with Immunoglobulin G4-Related Disease Mimicking Multiple Meningiomas: A Case Report and Review of the Literature

BACKGROUND

Immunoglobulin G (IgG)4-related disease is a syndrome that forms inflammatory pseudotumors with increasing IgG4-positive plasma cells and lymphocytes infiltrating the exocrine gland and other organs. The concept of this disease gradually has gained more recognition. However, reports of intracranial pseudotumors associated with IgG4-related disease are very rare. The purpose of this report is to provide further information helpful in distinguishing IgG4-related disease from multiple meningiomas.

CASE DESCRIPTION

We report a case of a 62-year-old man who presented with visual disturbance and quadrantanopia of the right eye. Magnetic resonance imaging revealed uniformly enhancing masses located near the right paraclinoid at the right Meckel's cave and along the left foramen magnum. He had experienced autoimmune pancreatitis 7 years previously, and the condition had responded to steroid therapy. Laboratory data revealed elevation of IgG (1877 mg/dL) and IgG4 (405 ng/dL). The right paraclinoidal lesion causing visual disturbance was subtotally removed, which provided sufficient decompression of the right optic nerve. IgG4 was strongly positive on immunohistochemical staining, and we started oral corticosteroid medication. Consequently, all lesion masses shrank remarkably within 1 month.

CONCLUSION

There have been a growing number of reports of such multiple pseudotumors associated with IgG4-related disease. In differential diagnosis, this disease entity requires special attention when multiple dural-based tumors are observed. Preoperative presumption is very important because this disease is likely to respond to steroid therapy.

Sinonasal and ventral skull base inflammatory pseudotumor: a systematic review

OBJECTIVES/HYPOTHESIS

Inflammatory pseudotumor is a benign idiopathic inflammatory process often misdiagnosed as an infection or neoplasm. This review analyzes all reported cases of sinonasal and ventral skull base inflammatory pseudotumor to date, and provides a framework for evaluation and management of this uncommon condition.

DATA SOURCES

MEDLINE/PubMed database.

REVIEW METHODS

A search for articles related to sinonasal and ventral skull base inflammatory pseudotumor, along with bibliographies of those articles, was performed. Demographics, presentation, radiographic findings, treatment, follow-up, and outcome were analyzed.

RESULTS

Thirty-three articles were reviewed, including a total of 87 patients. The most common presenting symptom was vision change (58.6%). Sinonasal and ventral skull base inflammatory pseudotumor was found in the cavernous sinus in 46.0% of cases. The lesion appeared isointense (66.7% of cases) and homogeneously enhancing on T1-weighted magnetic resonance imaging (MRI), whereas it appeared hypointense on T2-weighted MRI in 90.7% of cases. Inflammatory pseudotumor appeared hyperdense on computed tomography in 78.9% of cases. Histopathological analysis of biopsied specimens revealed presence of inflammatory cells (94.4%) and fibrosis (80.3%). Corticosteroids alone were the most common treatment modality (55.2%), resulting in disease-free patients in 22.9% of cases over a median follow-up period of 17.6 months. Surgical management alone was uncommon (8.0%), but showed high success rate (57.1%).

CONCLUSION

This review is the most comprehensive analysis of sinonasal and ventral skull base inflammatory pseudotumor to date. Radiologic findings and histopathological analysis are essential for diagnosis. Corticosteroids are the most common treatment modality. Surgery, although uncommon, appears to be an efficacious treatment modality.

IgG4-related kidney disease: MRI findings with emphasis on the usefulness of diffusion-weighted imaging

OBJECTIVES

To investigate the imaging findings of immunoglobulin G4 (IgG4)-related kidney disease (IgG4-KD) on magnetic resonance imaging (MRI) including diffusion-weighted imaging (DWI) and to evaluate the usefulness of DWI in lesion detection.

METHODS

This retrospective cohort study included 31 patients with IgG4-KD who underwent MRI covering both kidneys. Two radiologists reviewed in consensus the MR images to determine the distribution pattern (location, laterality, and multiplicity) and the visually assessed signal intensity (hypointense, isointense or hyperintense) of the renal lesions compared to the normal renal parenchyma on each sequence. Per-patient sensitivity for detecting IgG4-KD and the number of detectable lesions were compared in T2-weighted images, DWI, and dynamic contrast-enhanced images.

RESULTS

IgG4-KD typically manifested as bilateral (83.9%), multiple (93.5%), and renal parenchymal (87.1%) nodules appearing isointense (93.5%) on T1-weighted images, hypointense (77.4%) on T2-weighted images, hyperintense (100%) on DWI (b=1000), and hypointense (83.3%) in the arterial phase and with a progressive enhancement pattern on dynamic contrast-enhanced images. The sensitivity of DWI for detecting IgG4-KD was significantly higher than that of T2-weighted images (100% vs. 77.4%, P=0.034). The median number of detectable lesions was significantly greater in DWI (n=9) than in T2-weighted images (n=2) and dynamic contrast-enhanced images (n=5) (P≤0.008).

CONCLUSIONS

The characteristic MRI findings of IgG4-KD were bilateral, multiple, renal parenchymal nodules with T2 hypointensity, diffusion restriction, and a progressive enhancement pattern. As DWI was useful in the detection of IgG4-KD, adding DWI to conventional MRI for patients suspected of having IgG4-KD may enhance the diagnosis.

IgG4 overexpression is rare in meningiomas with a prominent inflammatory component: a review of 16 cases

Meningiomas with prominent inflammation are traditionally classified as "lymphoplasmacyte-rich meningioma" (LPM). Both inflammatory and neoplastic meningeal proliferations have recently been linked to IgG4 disease, although a potential association with LPM has not been previously explored. Sixteen meningiomas with inflammatory cells outnumbering tumor cells were further characterized by CD3, CD20, CD68 and/or CD163, CD138, kappa, lambda, IgG and IgG4 immunostains. There were 11 female and 4 male patients, ranging from 22 to 78 (median 59) years of age. Tumors consisted of 10 World Health Organization (WHO) grade I, 5 grade II and 1 grade III LPMs. Immunohistochemically, the most numerous cell type was the macrophage in all cases followed by CD3-positive T cells and fewer CD20-positive B cells. Plasma cells ranged from moderate-marked (N = 5) to rare (N = 7), or absent (N = 4). Maximal numbers of IgG4 plasma cells per high power field (HPF) ranged from 0 to 32, with only two cases having counts exceeding 10/HPF. The IgG4/IgG ratio was increased focally in only two cases (30% and 31%). Additionally, plasma cells represented only a minor component in most examples, whereas macrophages predominated, suggesting that "inflammation-rich meningioma" may be a more accurate term. The inflammatory stimulus for most cases remains to be elucidated.

Immunoglobulin G4-related disease of the orbit: imaging features in 27 patients

BACKGROUND AND PURPOSE

Immunoglobulin G4-related disease is a systemic fibroinflammatory process of unknown etiology, characterized by tissue infiltration by immunoglobulin G4 plasma cells. The purpose of this study was to retrospectively identify the spectrum of imaging features seen in immunoglobulin G4-related disease of the orbit.

MATERIALS AND METHODS

This study included 27 patients with biopsy-proved immunoglobulin G4-related disease of the orbit and either a CT or MR imaging of the orbits. These CT or MR imaging examinations were evaluated for the following: extraocular muscle size, extraocular muscle tendon enlargement, lacrimal gland enlargement, infiltrative process in the orbital fat (increased attenuation on CT or abnormal signal on MR imaging), infraorbital nerve enlargement, mucosal thickening in the paranasal sinuses, and extension of orbital findings intracranially.

RESULTS

Extraocular muscles were enlarged in 24 of 27 (89%) patients, 21 (88%) bilaterally. In 32 of 45 (71%) affected orbits, the lateral rectus was the most enlarged muscle. In 26 (96%) patients, the tendons of the extraocular muscles were spared. Nineteen (70%) patients had lacrimal gland enlargement. Twelve (44%) patients had an infiltrative process within the orbital fat. Infraorbital nerve enlargement was seen in 8 (30%) patients. Twenty-four (89%) patients had sinus disease. Cavernous sinus or Meckel cave extension was seen in 3 (11%) patients.

CONCLUSIONS

In patients with extraocular muscle enlargement, particularly when the tendons are spared and the lateral rectus is the most enlarged, and even more so when other noted findings are present, immunoglobulin G4-related disease should be a leading differential consideration, even over more commonly known etiologies of extraocular muscle enlargement.

Location and frequency of lesions in patients with IgG4-related ophthalmic diseases

BACKGROUND

It is well-known that the lacrimal gland (LG) may be affected in IgG4-related ophthalmic disease (IgG4ROD). Recently, IgG4-related ophthalmic lesions other than those of the lacrimal gland have been reported. However, no study to date has revealed the details of these lesions. This study was conducted to evaluate the location and frequency of lesions found in conjunction with IgG4ROD using radiological imaging.

METHODS

Radiological images and clinical records of 65 patients collected from seven institutions in Japan were reviewed retrospectively. All patients had been pathologically diagnosed with IgG4ROD. Patients of mucosa-associated lymphoid tissue lymphoma associated with IgG4-related lesions were excluded. Orbital magnetic resonance imaging or computed tomography findings were evaluated.

RESULTS

Of the 65 patients, 31 (47.7 %) had lesions involving the LG alone, whereas 34 (52.3 %) had lesions involving the areas other than LG, including eight patients who had lesions without any LG involvement. IgG4-related ophthalmic lesions included LG enlargement in 57 patients (87.7 %), trigeminal nerve branch enlargement in 25 (38.5 %), extraocular muscle enlargement in 16 (24.6 %), diffuse orbital fat lesions in 15 (23.1 %), orbital mass lesions in 11 (16.9 %), eyelid lesions in eight (12.3 %), and nasolacrimal duct lesion in one (1.5 %). Six patients (9.2 %) presented with visual disturbance due to optic nerve disturbance, eight (12.3 %) with a restriction of ocular movement, and 19 (29.2 %) with exophthalmos.

CONCLUSIONS

Thirty-four (52.3 %) of the 65 IgG4ROD patients had lesions in areas other than LG. Lesions were found in the trigeminal nerve branch including pterygopalatine fossa, extraocular muscles, orbital fat, eyelid, and nasolacrimal duct.

Ophthalmic manifestations of IgG4-related disease: single-center experience and literature review

OBJECTIVES

IgG4-related disease (IgG4-RD) is an inflammatory disorder responsible for fibrosing, tumefactive lesions that can involve the lacrimal gland as well as the extraocular muscles, orbital soft tissues, sclera, and local nerves. We reviewed IgG4-related ophthalmic disease (IgG4-ROD), including the natural history, pathology, and treatment, based on our center's experience and that reported in the literature.

METHODS

We identified 27 patients with orbital manifestations from our IgG4-RD registry; six were excluded because no pathology was available for review. All 21 cases included had histopathologically confirmed diagnoses of IgG4-RD, 11 of which were of the orbital tissue. Other data were obtained by a retrospective medical records review. MEDLINE and PubMed literature searches in English were conducted to identify articles for a literature review on the topic.

RESULTS

Patients with IgG4-ROD were predominantly male (57%) and had an average age at symptom onset of 50 years (range: 21-79 years). The lacrimal gland was the most commonly involved structure (62%). Most patients (71%) had bilateral disease and extra-orbital involvement (71%); these patients also had elevated serum IgG4 concentrations compared to those with unilateral disease and no extra-orbital disease. Ten patients improved following rituximab treatment.

CONCLUSIONS

Ophthalmic involvement is a common manifestation of IgG4-RD and can affect nearly every orbital structure. Consideration of IgG4-RD and accurate diagnosis by biopsy have important implications for prognosis and treatment following the distinction of this condition from the Sjögren syndrome (SjS), granulomatosis with polyangiitis (GPA, formerly Wegener's), sarcoidosis, lymphoma, infection, and other disorders. Rituximab holds promise as an effective steroid-sparing agent or therapy for steroid-resistant cases.

IgG4-related disease of the head and neck: CT and MR imaging manifestations

Immunoglobulin G4 (IgG4)-related disease is a recently established systemic disease that commonly involves the head and neck, including the salivary glands, lacrimal glands, orbits, thyroid gland, lymph nodes, sinonasal cavities, pituitary gland, and larynx. Although the definitive diagnosis of IgG4-related disease requires histopathologic analysis, elevated serum IgG4 levels are helpful in making the diagnosis. Because of the proposed clinical diagnostic criteria for this disease, cross-sectional imaging modalities such as computed tomography (CT) and magnetic resonance (MR) imaging play an important diagnostic role. CT and MR imaging findings of IgG4-related disease are usually nonspecific. At CT, involved organs may demonstrate enlargement or decreased attenuation; at T2-weighted MR imaging, they may have relatively low signal intensity owing to their increased cellularity and amount of fibrosis. Some pathologic entities involving the head and neck are now considered to be part of the IgG4-related disease spectrum, including idiopathic orbital inflammatory syndrome (inflammatory pseudotumor), orbital lymphoid hyperplasia, Mikulicz disease, Küttner tumor, Hashimoto thyroiditis, Riedel thyroiditis, and pituitary hypophysitis. Because involvement of multiple sites is common in IgG4-related disease, radiologists should be familiar with manifestations of this systemic process outside the head and neck, in organs such as the pancreas, bile ducts, gallbladder, kidneys, retroperitoneum, mesentery, lungs, gastrointestinal tract, and blood vessels. Moreover, IgG4-related disease usually demonstrates a dramatic response to corticosteroid therapy, and radiologists should be familiar with its clinical and imaging manifestations to avoid a delay in diagnosis or unnecessary invasive interventions.

IgG4-related disease: nomenclature, clinical features, and treatment

Concepts about IgG4-related disease (IgG4-RD) are now emerging swiftly. The condition has been identified in virtually every organ system, and its features are often excellent mimickers of malignancies, infections, and other immune-mediated disorders. Recommendations for nomenclature were proposed by the Organizing Committee of the 2011 International IgG4-related disease Symposium, and guidelines for the pathologic diagnosis of this condition have been published by an international group of experts. Experience with treatment regimens is growing. Glucocorticoids and B-cell depletion strategies both appear to be effective and are the subject of ongoing studies. This article reviews the current thought and understanding of this disease with regard to nomenclature, organ system involvement, and approaches to therapy.

Immunoglobulin G4-related sclerosing disease involving the urethra: case report

Immunoglobulin G4 (IgG4)-related sclerosing disease is a systemic disease characterized by extensive IgG4-positive plasma cells and T-lymphocyte infiltration in various organs. We described the imaging findings of an IgG4-related inflammatory pseudotumor in the urethra. The urethral mass showed isoattenuation on unenhanced CT images, delayed enhancement on enhanced CT images, iso- to slight hyper-intensity on T1 and T2 weighted magnetic resonance images, diffusion restriction on diffusion weighted images, and heterogeneously low echogeneity on ultrasonography.

MR imaging of IgG4-related disease in the head and neck and brain

SUMMARY

IgG4-related disease is characterized by histologic fibrosis with IgG4-positive plasma cell infiltration. Our study evaluated MR imaging features of IgG4-related disease in the head and neck and brain. Images from 15 patients were retrospectively evaluated for the location, signal intensity, and enhancement patterns of lesions. Lacrimal gland enlargement was observed in 8 cases. Other lesions included orbital pseudotumor in 5, pituitary enlargement in 5, and cranial nerve enlargement in 7; the infraorbital nerve was involved in 4. All lesions were hypointense on T2-weighted images, which is typical for IgG4-related lesions. Multiple sites were involved in the head and neck and brain in 11 patients. The diagnosis of IgG4-related disease should be considered in a patient presenting with T2 hypointense lacrimal gland, pituitary, or cranial nerve enlargement, or a T2 hypointense orbital mass, especially if multiple sites in the head and neck are involved in the presence of elevated serum IgG4.

IgG4-related inflammatory pseudotumor of the central nervous system responsive to mycophenolate mofetil

Orbital apex and skull base masses often present with neuro-ophthalmic signs and symptoms. Though the localization of these syndromes and visualization of the responsible lesion on imaging is typically straightforward, definitive diagnosis usually relies on biopsy. Immunohistochemistry is important for categorization and treatment planning. IgG4-related disease is emerging as a pathologically defined inflammatory process that can occur in multiple organ systems. We present two patients with extensive inflammatory mass lesions of the central nervous system with immunohistochemistry positive for IgG4 and negative for ALK-1 as examples of meningeal based IgG4-related inflammatory pseudotumors. In both patients, there was treatment response to mycophenolate mofetil.

IgG4-Related Perineural Disease

Aims. To elucidate characteristics of IgG4-related disease involving the peripheral nervous system. Methods. Retrospective review of 106 patients with IgG4-related disease identified 21 peripheral nerve lesions in 7 patients. Clinicopathological and radiological features were examined. Results. Peripheral nerve lesions were commonly identified in orbital or paravertebral area, involving orbital (n = 9), optic (n = 4), spinal (n = 7), and great auricular nerves (n = 1). The predominant radiological feature was a distinct perineural soft tissue mass, ranging 8 to 30 mm in diameter. Histologically, the epineurium was preferentially involved by massive lymphoplasmacytic infiltration rich in IgG4⁺ plasma cells. All lesions were neurologically asymptomatic and steroid-responsive at the first presentation, but one recurrent lesion around the optic nerve caused failing vision. Conclusion. IgG4-related disease of the peripheral nervous system is characterized by orbital or paravertebral localization, perineural mass formation, and rare neurologic symptoms. The term “IgG4-related perineural disease” seems appropriate to describe this entity.