Immunoglobulin G4-related hypertrophic pachymeningitis: A case-oriented review

IgG4-related disease in the nervous system

IgG4-related disease (IgG4-RD) is a recently described multisystemic disorder with a spectrum of manifestations that continue to be described. Nonetheless, there are recognised distinct patterns of disease. Neurological involvement is rare, particularly in isolation, but IgG4-RD may present with orbital disease, hypophysitis or pachymeningitis. Typically, it is highly responsive to treatment. This review highlights neurological manifestations of IgG4-RD and emphasises the importance of a high index of clinical suspicion to facilitate investigation and appropriate management, avoiding irreversible tissue damage and neurological dysfunction. We present a treatment algorithm for suggested management of IgG4-RD affecting the nervous system.

Intrathecal IgG4 synthesis in IgG4 related spinal hypertrophic pachymeningitis: a case report

Immunoglobulin G4 (IgG4) related hypertrophic pachymeningitis of the spinal cord is a rare condition, characterized by infiltration of the spinal meninges with IgG4-producing plasma cells and subsequent hypertrophic fibrosis. Here, we report on a 65-year-old woman with IgG4 associated hypertrophic spinal pachymeningitis, in whom cerebrospinal fluid (CSF) analysis was a decisive diagnostic tool. Not only could we demonstrate an intrathecal IgG4 production, but also IgG4 positive plasma cells in CSF. Following decompressive surgery, diagnosis of IgG4 associated hypertrophic pachymeningitis was confirmed histologically. Surgery and immunosuppressive therapy with rituximab were associated with clinical improvement. This case highlights CSF analyses as diagnostic tool for detection of IgG4 related hypertrophic pachymeningitis.

A case of IgG4-related disease manifesting as a spinal epidural mass

IgG4-related disease is an immune-mediated fibroinflammatory condition. Isolated manifestation in the spine as hypertrophic pachymeningitis is very rare and the mass-like lesion on MRI often mimic tumour or infection. Patients would present with symptoms that result from mass effect or neurovascular compression. Studies showed that serum and CSF IgG4 levels are rarely informative, and therefore, tissue biopsy is crucial for accurate diagnosis. Apart from supporting the diagnosis, MRI is helpful in delineating the extent of disease and follow-up after treatment. A 18F-FDG PET/CT scan is useful in detecting systemic manifestations of IgG4-related disease. Although IgG4-related disease generally responds well to corticosteroid at inflammatory state, relapse is not uncommon. Current treatment strategies for IgG4-related hypertrophic pachymeningitis are high dose corticosteroid therapy and early decompressive surgery to avoid chronic neurological complications. We described a case of a 27-year-old gentleman complaining of lower limb weakness and numbness. MRI showed a mass-like epidural lesion at the thoracic spine causing cord compression. Open biopsy of the epidural mass demonstrated histopathological characteristics of IgG4-related disease. Patient responded well to early surgical decompression of the spinal cord and corticosteroid as evidenced by symptom improvement and resolving mass on subsequent MRI study. However, a follow-up MRI revealed disease recurrence years later.

Hypertrophic pachymeningitis of the internal auditory canal and cerebellopontine angle from a large recurrent attic cholesteatoma

OBJECTIVES

To describe a rare complication of cholesteatoma.

METHODS

Case report with literature review.

RESULTS

We report a case of a 37-year-old male who presented for evaluation of otorrhea, headache, and progressive left sensorineural hearing loss. Clinical and radiologic evaluation demonstrated a large recurrent attic cholesteatoma with erosion into the lateral and superior semicircular canals, and diffuse enhancement of the internal auditory canal and cerebellopontine angle suggestive of hypertrophic pachymeningitis secondary to cholesteatoma. After treatment with a course of antibiotics and canal wall down mastoidectomy surgery for cholesteatoma exteriorization, he experienced improvement of his symptoms and resolution of hypertrophic pachymeningitis.

CONCLUSION

Hypertrophic pachymeningitis is a rarely described complication of cholesteatoma. In the context of cholesteatoma, treatment with antibiotics and surgical removal or exteriorization of cholesteatoma are effective treatments for HP.

Neurological Involvement in a Portuguese Cohort of IgG4-Related Disease

INTRODUCTION

Neurological involvement in immunoglobulin G4-related disease (IgG4-RD) is increasingly recognized. Its diagnosis can be challenging due to clinical mimics and difficulty in obtaining nervous system biopsies. The aim of this study was to describe a cohort of neurological IgG4-RD patients.

METHODS

Patients were recruited from a neuroimmunology tertiary center. Clinical, laboratory, neuroimaging and histological data were reviewed.

RESULTS

Fifteen patients (60% women), with a median age of 53 years (48.5 - 65.0) were included: 13 (86.7%) classified as possible IgG4-RD, one (6.7%) as probable and one (6.7%) as definitive. The most common neurological phenotypes were meningoencephalitis (26.7%), orbital pseudotumor (13.3%), cranial neuropathies (13.3%), peripheral neuropathy (13.3%), and longitudinally extensive transverse myelitis (LTEM) (13.3%). Median serum IgG4 concentration was 191.5 (145.0 - 212.0) mg/dL. Seven in 14 patients had CSF pleocytosis (50.0%) and oligoclonal bands restricted to the intrathecal compartment, while most cases presented elevated CSF proteins (64.3%). Magnetic resonance imaging abnormalities included white matter lesions in four (26.7%), hypertrophic pachymeningitis in two (13.3%), and LETM in two (13.3%). Two patients had biopsy-proven IgG4-RD in extra-neurological sites.

CONCLUSION

This study highlights the phenotypical variability of the neurological IgG4-RD. Biopsy inaccessibility reinforces the importance of new criteria for the diagnosis of this subset of patients.

A case report of Immunoglobulin-G4-related hypertrophic sclerosing pachymeningitis

IgG4-related diseases (IgG4-RD) are a group of chronic progressive autoimmune diseases of unknown etiology that are increasingly recognized as an important pathophysiological basis for a variety of systemic diseases. It is thought to involve almost any organ of the body, but the involvement of the central nervous system is relatively rare. We report the case of a 56-year-old male patient admitted to the hospital d recurrent dizziness and nausea for more than 3 months. The preoperative imaging was misdiagnosed as a meningioma, with this lesion demonstrated localized inhomogeneous thickening of the meninges in the left parietal region on T2-weighted and T2 fat suppression sequences with localized nodular changes. The patient's final pathologic diagnosis was IgG4-associated sclerosing thick encephalitis. The diagnosis of IgG4-associated hypertrophic pontine meningitis is challenging. Clinically, IgG4-associated sclerosing diseases usually present as mass-like lesions, which can be easily misdiagnosed as neoplastic lesions due to their similar appearance. These fundamentally recognized autoimmune disorders respond well to corticosteroid therapy. Therefore, accurate detection of IgG4-related disease is critical to prevent patients from undergoing unnecessary surgery.

Immunoglobulin G4-related hypertrophic pachymeningitis with an isolated scalp mass mimicking a brain tumor: a case report and literature review

Immunoglobulin G4-related disease (IgG4-RD) is an autoimmune disorder associated with fibroinflammatory conditions that can affect multiple organs. Hallmark histopathological findings of IgG4-RD include lymphocytic infiltration of IgG4-positive plasma cells, storiform fibrosis, and obliterative phlebitis. However, little is known about central nervous system involvement of IgG4-RD. Hypertrophic pachymeningitis (HP) has recently been reported as a manifestation of IgG4-RD, which may have previously been demonstrated in a significant percentage of idiopathic cases. Herein, we report a rare case of a 63-year-old male who presented with a scalp mass that mimicked a brain tumor. He was diagnosed with IgG4-related HP (IgG4-RP) after surgery. This case suggests that awareness of a possibility of IgG4-RP in patients with isolated scalp masses, even in the absence of systemic symptoms, is crucial. A combination of careful history taking, evaluation of serum IgG4-levels and imaging as an initial work-up, followed by tissue biopsy, is important for the differential diagnosis of IgG4-RP, malignancy, and other infectious diseases.

Giant skull base mass need not be a tumor - a rare presentation of IgG4-related disease

BACKGROUND

Giant intracranial 'IgG4-related' lesions are uncommon. They may present as pachymeningitis or localized mass. Here we report, probably, the largest IgG4 skull base mass ever to be reported.

CASE

A 40-year male presented with headache, diplopia, right-sided sensori-neuronal hearing loss, and left spastic hemiparesis. Magnetic resonance imaging showed a lesion of 8.5 cm extending from the paranasal sinuses to the right petroclival region with uniform contrast enhancement and T2 hypointensity. Endonasal biopsy revealed respiratory epithelium with fibrosis, and lymphoplasmacytic infiltrate having IgG4 positive cells >30/HPF suggestive of 'IgG4-related' disease. Serum IgG4 was within normal levels. With oral prednisolone 60 mg given daily for 6 weeks and then tapered off over 8 weeks, he improved symptomatically.

CONCLUSION

Though rare, 'IgG4-related' disease can also present as a giant skull base mass and should be kept as a differential to fungal granulomas and meningiomas. As they improve dramatically with medical management, extensive skull base resection should not be planned before obtaining a tissue biopsy, especially when there is extension into paranasal sinuses and T2 hypointensity.

A selected case series of idiopathic hypertrophic pachymeningitis in a single center: Pathological characteristics and case-oriented review

Hypertrophic pachymeningitis (HP) is a relatively rare disease of the central nervous system characterized by local or diffuse fibrous thickening of the dura mater. At present, there is still insufficient research on the pathogenesis and treatment strategies of this disease. We reported a continuous case series of seven patients with idiopathic HP (IHP), and also details one case of immunoglobulin G4-related HP requiring surgical intervention. Early diagnosis and appropriate surgical intervention for IHP could prevent the progression of permanent neurological damage and spinal cord paraplegia.

IgG4-related hypertrophic pachymeningitis with chronic subdural haematoma

Hypertrophic pachymeningitis is a rare disorder of the dura mater of the spine or brain. It can be caused by inflammatory, infective or neoplastic conditions or can be idiopathic. We report a man with hypertrophic pachymeningitis and bilateral chronic subdural haematoma caused by IgG4-related disease. We highlight the diagnostic challenges and discuss possible underlying mechanisms of subdural haematoma formation in inflammatory conditions. Isolated IgG4-related hypertrophic pachymeningitis with chronic subdural haematoma is very rare; previously reported cases have suggested a possible predilection for men in their sixth decade, presenting with headache as the dominant symptom. Given the rarity and complexity of the condition, it should be managed in a multidisciplinary team setting.

IgG4-related pachymeningitis-Long term follow up and outcome of six patients

OBJECTIVE

Our understanding of IgG4-RD and pachymeningitis has grown substantially, but the optimal approach for diagnosis, management, and long-term outcomes is still an area of uncertainty.

METHODS

HUVAC is a database for IgG4-RD patients, this database was retrospectively evaluated for pachymeningeal disease. Demographic, clinical, serological, imaging, histopathological data, and treatment details were re-interpreted in patients with pachymeningitis.

RESULTS

Among 97 patients with IgG4-RD, 6 (6.2%) had pachymeningitis. None of these patients had extracranial features, and also, in most of the patients, serum IgG4 levels were normal. Tentorium cerebelli and transverse sinus dura were the most commonly involved in the posterior fossa. During 18 months of median follow-up on steroid+-rituximab, none of them relapsed as pachymeningitis.

CONCLUSION

Our patients were mainly older males with sole neurological involvement. Non-specific headache was the most common manifestation, and serum IgG4 levels were not useful for diagnosis. Typical radiology and tentorial thickening should suggest IgG4-RD and prompt an early biopsy. Moreover, accompanying hypophysitis could also be a clue. With steroids+ rituximab treatment, no relapse related to meningeal involvement was seen in long-term follow-up.

Epiduritis related to IgG4 disease: A very rare cause for spinal cord compression

Background

Inflammatory pseudotumors are rare, and those attributed to immunoglobulin G4 (IgG4) diseases are even less frequently encountered. Here, we reviewed 41 cases from the literature of spinal inflammatory pseudotumors due to IgG4 and have added our single new case.

Case Presentation

A 25-year-old male presented with progressive back pain, bilateral paraparesis, and sphincter dysfunction. His deficit was attributed to MR-documented posterolateral lesion between the T5 and T10 levels for which he levels underwent a T1-T1010 laminectomy. The pathology revealed an immunoglobulin G4-related inflammatory pseudotumor. Postoperatively, the patient additionally required systemic and epidural administration of glucocorticoids.

Conclusion

IgG4-related disease is an emerging clinical condition that rarely involves the central nervous system. Spinal inflammatory pseudotumors, including IgG4 disease, should be more commonly considered among the potential differential diagnoses of lesions compressing the spinal cord.

Treatment of IgG4-related disease-associated hypertrophic pachymeningitis with intrathecal rituximab: a case report

IgG4-related disease-associated hypertrophic pachymeningitis (IgG4RD-HP) is a fibroinflammatory autoimmune disorder in which diagnosis is difficult without biopsy. Guidance on management of disease refractory to glucocorticoids and intravenous rituximab is limited. We present the case of a 68-year-old woman with IgG4RD-HP who developed sensorineural hearing loss with associated bulky basilar pachymeningeal enhancement. Her cerebrospinal fluid was inflammatory and had an elevated IgG4 concentration, strongly suggestive of IgG4RD-HP. Biopsy of involved meninges was not possible due to surgical risk. Over years she developed bilateral optic neuropathies and hydrocephalus, requiring intravenous rituximab and ventriculoperitoneal shunt. Her disease was refractory to glucocorticoids. Despite maintenance intravenous rituximab, she developed slowly progressive symptoms of intracranial hypertension and hydrocephalus with persistently inflammatory spinal fluid. Switching to intrathecal rituximab therapy led to dramatic improvement in gait and headache and reduced pachymeningeal bulk and metabolic activity. In patients with IgG4RD-HP refractory to glucocorticoids and intravenous rituximab, intrathecal rituximab may be an efficacious therapy.

Case report: Clinical highlights and radiological classification of IgG4-related spinal pachymeningitis: A rare case series and updated review of the literature

Purpose

Hypertrophic pachymeningitis associated with immunoglobulin G4-related disease (IgG4-RD) has been rarely reported, and there is little information and no clear consensus on the management of IgG4-related spinal pachymeningitis (IgG4-RSP). The present study described its possible clinical features, including the symptoms, imaging, treatment and prognosis of patients with IgG4-RSP.

Methods

We report three patients who presented with progressive neurological dysfunction due to spinal cord compression. Relevant articles were searched from the PubMed, Web of Science, and Embase databases, and the resulting literature was reviewed.

Results

The literature review provided a summary of 45 available cases, which included three cases from our center. Progressive worsening of neurological impairment was observed in 22 patients (48.9%). The lesions involved the thoracic spine (n=28, 62.2%), cervical spine (n=26, 57.8%), lumbar spine (n=9, 20.0%), and sacral spine (n=1, 2.2%). Furthermore, the lesions were located in the dura mater (n=18, 40.0%), epidural space (n=17, 37.8%), intradural-extramedullary space (n=9, 20.0%), and intramedullary space (n=1, 2.2%). On magnetic resonance imaging (MRI), the lesions generally appeared as striated, fusiform, or less often lobulated oval changes, with homogeneous (n=17,44.7%) and dorsal (n=15,39.5%) patterns being the most common. Thirty-five patients had homogeneous T1 gadolinium enhancement. Early surgical decompression, corticosteroid treatment, and steroid-sparing agents offered significant therapeutic advantages. A good therapeutic response to disease recurrence was observed with the medication.

Conclusion

The number of reported cases of IgG4-RSP remains limited, and patients often have progressive worsening of their neurological symptoms. The features of masses identified on the MRI should be considered. The prognosis was better with decompression surgery combined with immunosuppressive therapy. Long-term corticosteroid treatment and steroid-sparing agent maintenance therapy should be ensured. A systemic examination is recommended to identify the presence of other pathologies.

Serum IgG4 level during initial treatment as a predictor of relapse in IgG4-related disease

INTRODUCTION

We aimed to investigate the predictors of relapse in immunoglobulin G4-related disease (IgG4-RD), focusing on the serum IgG4 levels during initial treatment.

METHODS

We retrospectively recruited 57 patients with IgG4-RD who were treated with immunosuppressants and elevated serum IgG4 levels in a tertiary hospital between January 2011 and December 2020. They were followed up for ≥ 6 months after initiation of immunosuppressive therapy. Clinical and laboratory findings including serum IgG4 levels (reference value: 6-121 mg/dL) were compared between relapsed (n = 13) and non-relapsed (n = 44) groups. Multivariate Cox regression analysis was used to assess the predictors for relapse. We performed a Kaplan-Meier analysis with a log-rank test to evaluate the cumulative relapse rate for two years.

RESULTS

Median serum IgG4 levels at baseline were 321 mg/dL in the relapsed group and 299 mg/dL in the non-relapsed group. Serum IgG4 levels were normalized after six months in five (38.5%) relapsed and 28 (63.6%) non-relapsed patients. In multivariate Cox regression analysis, the normalization of serum IgG4 levels at six months was associated with a lower risk of relapse, with a hazard ratio of 0.232 (p = 0.019). Central nervous system involvement was associated with the relapse, with a hazard ratio of 21.130 (p = 0.015). The cumulative relapse rate for two years was lower in the normal serum IgG4 group at six months than in the elevated serum IgG4 group at six months (p = 0.027).

CONCLUSION

Our study suggests that normalization of serum IgG4 levels during immunosuppressive treatment for IgG4-RD independently predicts relapse-free outcomes. Thus, monitoring serum IgG4 levels might be used as a marker of prognosis.

IgG4-related brain pseudotumor mimicking CNS lymphoma. A case report

Here, we report a case of IgG4-related brain pseudotumor (IgG4-BP) in a 39-year-old woman, mimicking central nervous system (CNS) lymphoma. She presented with headache, fever, and fatigue. Her medical history was notable for appearance of a tumefactive brain lesion seven years before. Brain biopsy performed at the age of 32 revealed nonspecific inflammatory changes, and her condition improved with oral low-dose steroid therapy. Magnetic resonance imaging performed at the age of 39 identified a hyperintensity lesion with edema located at the medial temporal lobe region adjacent to the inferior horn of the left lateral ventricle on fluid-attenuated inversion recovery images, which showed gadolinium-contrast enhancement on T1-weighted images and a slightly hyperintensity signal on diffusion-weighted images. Methionine-positron emission tomography (PET) depicted a high methionine uptake in the lesion. Additionally, soluble levels of interleukin (IL)-2 receptor (sIL-2R) and IL-10 were increased in cerebrospinal fluid (CSF). Based on these findings, we suspected CNS lymphoma and performed partial resection of the brain lesion. Pathological examination revealed prominent lymphocytic infiltration associated with plasma cell infiltration. Most of the plasma cells were immunoreactive for IgG4. Storiform fibrosis and partially obliterative phlebitis were concomitantly observed. Thus, the patient was diagnosed as having IgG4-BP. To the best of our knowledge, this is the first case report of IgG4-BP with detailed findings obtained by CSF testing, methionine-PET, and pathological examination. Because IgG4-related diseases can present as a pseudotumor that mimics CNS lymphoma, it is essential to carefully differentiate IgG4-BP from CNS lymphoma.

Pachymeningitis in Biopsy-Proven Sarcoidosis

Background and Objectives

Meningeal inflammation is one of the most common manifestations of neurosarcoidosis, occurring in 16%–69% of affected patients. While the clinical and radiographic features of leptomeningitis in neurosarcoidosis are well known, those of pachymeningitis are far less clear. Our primary aim was to study the clinicoradiographic features of pachymeningeal involvement in neurosarcoidosis and its evolution over time in response to treatment.

Methods

Patients with a diagnosis of neurosarcoidosis seen at Emory University (January 2011–August 2021) were included if pachymeningeal involvement was evident by MRI and the patient's sarcoidosis was pathologically confirmed (from a CNS or non-CNS site).

Results

Twenty-six of 215 (12.1%) patients with neurosarcoidosis qualified for inclusion. Pathologic confirmation came from CNS tissue in 50%. The median age of onset was 43.5 years; most were male (16/26, 61.5%). Symptoms were primarily related to pachymeningitis in 20/26 (76.9%). Headache (19/26, 73.1%), visual dysfunction (12/26, 46.2%), and seizures (7/26, 26.9%) were the most common symptoms. All patients had cranial pachymeningitis; only a single patient undergoing spinal imaging (1/11, 9.1%) had spinal pachymeningitis. The falx cerebri (16/26, 61.5%) was the most commonly affected dural structure, but the anterior and middle cranial fossae and tentorium cerebelli were frequently involved (12/26 each, 46.2%). The pachymeningeal lesions were unifocal (11/26, 42.3%) or multifocal (15/26, 57.7%) in distribution, nodular morphologically (23/25, 92.0%), and homogeneously enhancing (24/25, 96.0%). Symptomatic improvement occurred with steroids initially in 22/25 (88.0%). Ultimately, 23/26 (88.5%) required initiation of steroid-sparing immunosuppressants, including 8/26 (30.8%) eventually undergoing TNF inhibition. Pachymeningeal relapses occurred in 7/26 (26.9%). The median clinical follow-up was 48 months. The median modified Rankin scale score at last follow-up improved to 1.0 from 2.0 at presentation.

Discussion

Pachymeningitis due to sarcoidosis often presents with headaches, visual dysfunction, and seizures; it usually affects the dura of the falx cerebri, anterior and middle cranial fossae, and tentorium cerebelli and tends to require steroid-sparing immunosuppressants. It has the potential to relapse, but the prospect for recovery is good.

Immunoglobulin G4-Related Disease Involving Various Head and Neck Regions: A Case Report

Immunoglobulin G4 (IgG4) related disease (IgG4-RD) is currently considered an immune-mediated condition and is recognized as a disorder group with common pathological, hematological, and clinical characteristics. This disease may involve diverse organs of the head and neck, and include mainly the lacrimal gland, orbit, thyroid gland, pituitary gland, and the meninges. Here, we report a case of IgG4-RD in a 65-year-old female showing head- and neck-limited but synchronously and mainly manifesting as otalgia and facial neuritis.

Refractory IgG4-related disease complicated with organising pneumonia and hypertrophic pachymeningitis

Immunoglobulin G4 (IgG4)-related disease (IgG4-RD) involves multiple organs, including the lungs and central nervous system. Lung lesions are frequently reported as mass lesions or non-specific interstitial pneumonia, whereas organising pneumonia (OP) due to IgG4-RD is rare. Furthermore, limited information is currently available on hypertrophic pachymeningitis (HP). We herein report a case of IgG4-RD complicated with OP and HP. The diagnosis was confirmed based on the serum concentration of IgG4 and the results of salivary gland and transbronchial lung biopsies. HP did not respond to steroid monotherapy and was also resistant to rituximab and intravenous cyclophosphamide; however, the combination therapy of methotrexate and dexamethasone was effective.

IgG4-Related Hypertrophic Pachymeningitis with Skull Base Involvement Presenting with Isolated Glossopharyngeal and Vagus Nerve Palsy

We herein report a 70-year-old man diagnosed with IgG4-related hypertrophic pachymeningitis with skull base involvement, who presented with isolated glossopharyngeal and vagus nerve palsy. Contrast-enhanced magnetic resonance imaging (MRI) showed enhanced dural thickening of the posterior clivus and skull base involvement. When a patient with hypertrophic pachymeningitis presents with isolated cranial neuropathy without systemic manifestations or definite MRI abnormalities, it is difficult to make a diagnosis, and the patient may be misdiagnosed. This case suggests that a detailed radiological evaluation including contrast enhancement of the skull base is very important in patients with isolated glossopharyngeal and vagus nerve palsy.

The great imposter: A case report of IgG4-RD hypertrophic pachymeningitis with skull lytic lesion and pulmonary nodules

Immunoglobulin G4-related disease (Ig4RD) is an inflammatory condition with unique clinical, serological, and pathological features. In this study, we report a challenging diagnostic clinical case of Ig4RD diagnosed based on histopathology. This unique imitating nature reinforces that it is crucial to consider the diagnosis of IgG4-RD in those presenting with pachymeningitis.

IgG4-Related Disease Presenting as Hypertrophic Pachymeningitis

IgG4-related disease (IgG4-RD) is a multi-organ, immune-mediated inflammatory condition of unknown etiology characterized by infiltration of tissues by IgG4 producing plasma cells. IgG4-related disease (IgG4-RD) can ideally affect any organs, but the involvement of the central nervous system (CNS) is a rare entity. We present a case of a 67-year-old male who presented with diplopia with imaging showing hypertrophic pachymeningitis (HPM) and was diagnosed with IgG4-RD of the CNS based on histopathology report.

IgG4-related hypertrophic pachymeningitis with tumor-like intracranial and intracerebral lesions

OBJECTIVE

IgG4-related hypertrophic pachymeningitis is a rare fibroinflammatory disorder that may cause localized or diffused thickening of the dura mater. Misinterpretations of the clinical and imaging findings are common. Clinical manifestations depend on the location of the inflammatory lesion and on compression of neural structures leading to functional deficits. A dural biopsy is commonly needed for a definitive diagnosis. Immunomodulatory therapy is considered the therapy of choice.

METHODS

Four patients with IgG4-related hypertrophic pachymeningitis were identified over a 5-year period. Patient-related characteristics including age, preoperative workup, signs and symptoms of patients, and diagnostic procedures were evaluated. Furthermore, the surgical treatment and 5-year follow-up outcomes were analyzed.

RESULTS

There were two adults and two adolescents (mean age 32 years; range 15 to 67 years). Two patients were male, and two were female. No history of disease was known in any of the patients. Clinical symptoms were epilepsy (n = 2), ataxia and nausea (n = 1), and facial nerve palsy (n = 1). MR imaging studies showed contrast enhancing lesions in the temporal region in two patients, and in the cerebellar region in the other two patients. Subtotal resection was performed in two instances and a biopsy via a suboccipital retrosigmoid approach was obtained in the other two patients. Histochemical and immunohistochemical investigations revealed an IgG 4 disease in all of these patients. Immunomodulatorry therapy led to clinical stability during follow-up of 5 years in all four cases.

CONCLUSION

The diagnosis of IgG4-related hypertrophic pachymeningitis is challenging, but is of great relevance as treatment differs significantly from other forms of pachymeningitis and a specific therapeutic approach may avoid long-term neurological complications. Our series contributes to a better clinical characterization of this rare disease.

Autoimmune Meningitis and Encephalitis

Meningitis and encephalitis are inflammatory syndromes of the meninges and brain parenchyma, respectively, and may be identified either by finding definitive evidence of inflammation on tissue pathology or by cerebrocpinal fluid (CSF) analysis showing pleocytosis or intrathecal antibody synthesis. Clinicians evaluating undifferentiated meningitis or encephalitis should simultaneously consider autoimmune, infectious, and neoplastic causes, using patient risk factors, clinical syndrome, and diagnostic results including CSF and MRI findings to narrow the differential diagnosis. If an autoimmune cause is favored, an important early diagnostic question is whether a specific neural autoantibody is likely to be identified.

FDG PET/CT in 3 Cases of Hypertrophic Pachymeningitis Associated With Antineutrophil Cytoplasmic Antibody-Associated Vasculitis

ABSTRACT

Hypertrophic pachymeningitis associated with antineutrophil cytoplasmic antibody-associated vasculitis is a rare dural inflammatory disorder. We describe MRI and FDG PET/CT findings in 3 cases of hypertrophic pachymeningitis associated with antineutrophil cytoplasmic antibody-associated vasculitis. Enhanced brain MRI of the 3 cases showed linear enhancement of the thickened dura matter involving the skull base, tentorium, and/or convexity. On FDG PET/CT, the thickened dura matter showed diffusely increased FDG uptake with SUVmax ranging from 5.8 to 11.3. Familiarity with these MRI and FDG PET/CT findings is helpful for correct diagnosis and treatment.

A Unique Case of Encephalopathy with an Elevated IgG-4 and Extremely High Interleukin-6 Level and Delayed Myelodysplastic Syndrome

We herein report a 75-year-old man who developed disturbed consciousness with polynuclear cell dominant pleocytosis and low glucose and extremely high interleukin (IL)-6 levels in his cerebrospinal fluid. The biopsy specimen from his right supraclavicular lymph node showed the infiltration of inflammatory cells positive for IgG, IgG4 and IL-6. Prednisolone and azathioprine administered under suspicion of IgG4-related disease (IgG4-RD) or multicentric Castleman's disease (MCD) successfully remitted the symptoms. However, he developed myelodysplastic syndrome (MDS) and died 18 months later. The extremely high IL-6 may have been related to the rare neurological manifestations and development of MDS in the present case.

Neuroimaging findings in rheumatologic disorders

Patients with rheumatological diseases may present with neurological manifestations of peripheral and/or central nervous system (CNS). Symptoms may be related to underlying rheumatological disease or CNS effects of immune-modulating drugs. Early diagnosis and therapy may help prevent serious complications. Magnetic resonance imaging (MRI), given its excellent soft tissue details, is the preferred imaging modality when evaluating patients with rheumatological disease and suspected CNS involvement. We present a review of the neuroimaging manifestations of various rheumatic diseases with emphasis on the imaging findings on MRI.

Successful treatment of IgG4-related hypertrophic pachymeningitis with induction rituximab and dexamethasone followed by maintenance rituximab

IgG4-related disease (IgG4RD) with intracranial involvement is rare. We report a 56-year-old male who had an excellent response to rituximab and dexamethasone after going undiagnosed for 5 years. After 3 years of rituximab maintenance, he has no evidence of disease on brain MRI.

Imaging of IgG4-Related Disease in the Head and Neck: A Systematic Review, Case Series, and Pathophysiology Update

This systematic review aims to clarify and comprehensively detail the sometimes variable published imaging features as well as the pathogenesis, clinical diagnostic criteria, and treatment options of IgG4-Related Diseases (IgG4-RD) in the head and neck to aid the radiologist in diagnosing relapse and new sites of disease. A literature search in PubMed and EMBASE for reported cases of IgG4-RD was performed in December 2019. Case reports or series of IgG4-RD in the head and neck in adults that included sufficient imaging and pathology findings were included. This yielded 50 reports. IgG4-RD locations included the orbits, thyroid, pituitary gland, paranasal sinuses, salivary and parotid glands, larynx, pharynx, cervical lymph nodes, meninges, and skull base. Most lesions demonstrated non-specific homogenous CT attenuation, diffuse enhancement, isointense/low T2 signal intensity, and low T1 signal intensity. 6 cases from our institution followed previously reported imaging patterns.

Hypertrophic spinal pachymeningitis caused by ANCA-associated vasculitis revealed by 18F-FDG PET/CT: A case report

RATIONALE

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) can involve the central nervous system in estimatedly 15% of patients. Hypertrophic pachymeningitis causes inflammatory hypertrophy of the cranial or spinal dura mater and patients present with various neurological deficits. ANCA-associated hypertrophic spinal pachymeningitis has rarely been reported in literature. We report a case of AAV presenting with hypertrophic spinal pachymeningitis detected by 18F-FDG PET/CT.

PATIENT CONCERNS

A 66-year-old woman diagnosed with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis developed back pain, bilateral lower limb weakness, dysuria, and dysporia 1 month ago.

DIAGNOSIS

Contrast-enhanced MRI showed thickening and enhancement of the dura mater in the thoracic cord. Intraspinal hypermetabolism in the corresponding region was observed on 18F-FDG PET/CT. The patient was finally diagnosed with ANCA-associated hypertrophic spinal pachymeningitis.

INTERVENTIONS

The patient was treated with a higher dose of prednisone and cyclophosphamide.

OUTCOMES

After 2-week treatment, the patient's neurological symptoms improved rapidly and laboratory findings were ameliorated. A repeated contrast-enhanced MRI showed partial improvement of the disease in the thoracic cord.

LESSONS

18F-FDG PET/CT and contrast-enhanced MRI can aid in the clinical diagnosis and surveillance in AAV-associated hypertrophic spinal pachymeningitis and potentially facilitate early recognition and intervention to prevent irreversible neurological impairment.

Neurosurgical and neuro-immunological management of IgG4-related hypertrophic sclerosing pachymeningitis. A literature survey and discussion of a unique index case

BACKGROUND

Dural thickening is observed in lymphoma, dural carcinomatosis, meningioma, tuberculosis, and autoimmune diseases. We encountered a patient with dural thickening and complaints of neck and back pain, numbness and loss of strength in the hands. The patient also suffered from polychondritis and had previously received steroid and methotrexate treatment for this indication. The patients' serum was also positive for ANA, yet she did not have any other findings suggesting lupus. Our radiological and pathological analysis revealed IHSP (IgG4-related hypertrophic sclerosing pachymeningitis). In this review study, we provided a detailed literature survey to increase the awareness about IHSP in the neurosurgical community.

METHODS

MRI (magnetic resonance imaging)-based radiological analyses revealed a posterior extramedullary spinal mass extending from C2 to T2-T3 level. The dural mass was surgically excised and a broad panel of immunohistochemical markers including S100, EMA, CD246/ALK-1, CD45, CD20, CD79a, CD138, CD68, CD1a and CD34 was studied. Immunoglobulin heavy chain/kappa chain gene rearrangement analysis was performed which ruled out a lymphoproliferative disorder.

RESULTS

MRI and pathological findings suggested IHSP. As the disease relapsed with a new anterior extramedullary multilobulated lesion extending from C5 to T1 level, the patient is now closely monitored for further medical and surgical treatment.

CONCLUSIONS

IHSP is a relatively novel entity of hypertrophic pachymeningitis and should be included in the differential diagnosis of dural thickening. The fibrosis accompanying IHSP may not respond to medical treatment, which includes steroids and immunosuppressive agents. Additionally, neurological deficits, seizures, spinal decompression, hydrocephalus, or brainstem compression necessitate early surgical intervention. A continued vigilance is also necessary as the disease may relapse long-term following surgical treatment.

Immunoglobulin G4-related hypertrophic pachymeningitis with spinal cord compression: A case report

IgG4-related disease (IgG4-RD) is a recently recognized inflammatory condition that can be found in many organs. However, spinal involvement is rare and has been described only in case reports and series. Here, we report a rare case of spinal IgG4-RD that resulted in hypertrophic pachymeningitis with spinal cord compression. This case expands the phenotypic presentation for the neurological sequelae of IgG4-RD. Our case hints that spinal IgG4-RD may be misdiagnosed, and IgG4-RD in patients should be considered when the patient has a dural mass. Although early surgery, steroids, and/or immunosuppressive therapy may prevent neurological complications, the side effects should receive more attention during treatment.

Immunoglobulin G4-Related Hypertrophic Pachymeningitis of the Spine: A Case Report and Systematic Review of the Literature

BACKGROUND

Spinal immunoglobulin G4-related hypertrophic pachymeningitis (IgG4-HP) is a rare disease. Little information is known regarding the diagnosis, management, and prognosis of patients with spinal IgG4-HP.

METHODS

The authors present a case of spinal IgG4-HP with a systematic review of the literature according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Relevant studies (up to April 2020) that reported patients with spinal IgG4-HP, based on the criteria of Japan College of Rheumatology, were identified from the PubMed and Cochrane Library databases.

RESULTS

This systematic review identified 33 patients, including the present case, of whom 21 were male and 12 were female. The mean value of age was 51.2 (±12.6) years. Eight patients had systemic involvement. In addition, among 33 patients, 13 patients had an elevated serum IgG4. Surgery was performed in 31 patients. Steroid therapy alone and steroid therapy with immunosuppressants were effective in 94% and 100% of the cases, respectively. Furthermore, 31 of 33 patients reported improved outcomes, 1 patient died due to infection, and in 2 patients the data were not available.

CONCLUSIONS

Spinal IgG4-HP is a rare entity. In addition, it should be considered in the differential diagnosis of space-occupying lesions around the spinal cord. Histopathology with immunohistochemistry results provides the most reliable evidence for diagnosis. Steroid therapy is the first line of treatment. Surgical decompression may be required in patients presenting with nerve root and/or spinal cord compression. Long-term follow-up is necessary for patients with spinal IgG4-HP.

Inflammatory Manifestations of Systemic Diseases in the Central Nervous System

PURPOSE OF REVIEW

This review presents the current recommended therapeutic interventions for inflammatory disease in the central nervous system (CNS) secondary to systemic diseases of immune dysregulation. Treatment recommendations for CNS inflammation associated with rheumatologic conditions, immune-related adverse effects from immune checkpoint inhibitors (ICIs), and demyelinating disease from tumor necrosis factor-α (anti-TNFs) are explored. Additional therapeutic options for inflammation related to postviral syndromes and genetic immunodeficiencies are also discussed.

RECENT FINDINGS

In addition to treatment of mild, moderate, and severe CNS rheumatologic disease as guided by the European League Against Rheumatism (EULAR), early consideration of rituximab for severe IgG4-related disease and induction with anti-TNF therapy for severe neurosarcoidosis should be considered. Although often not first line, treatment options for CNS inflammatory diseases based on disease mechanism are emerging, including tocilizumab for Behcet's disease, natalizumab for ICI associated autoimmune encephalitis, and abatacept for treatment of infiltrative disease secondary to CTLA-4 deficiency. Hematopoietic stem cell treatments represent highly efficacious but risky options for autoimmunity related to genetic immunodeficiency.

SUMMARY

While early high dose steroids remains first line therapy for most CNS inflammatory conditions, a rapidly expanding arsenal of immune targeted therapies offers clinicians tailored disease specific options for treatment.

A Case With IgG4-Related Spinal Pachymeningitis Causing Spinal Cord Compression

Immunoglobulin G4 (IgG4)-related disease is a systemic disease characterized by sclerosing lesions and an increased serum IgG4 level. This condition can involve any organ, but IgG4-related spinal pachymeningitis is relatively rare. In the current study, we report a case of spinal cord compression caused by IgG4-related spinal pachymeningitis. A 39-year-old man presented to us with a 15-day history of back pain and a 3-day history of dysuresia, exacerbated by weakness in the lower extremities for 2 days. Cervical magnetic resonance imaging (MRI) showed strip-shaped abnormal signals along the anterior and posterior borders of the spinal cord at the C5–T4 levels. The IgG level in cerebrospinal fluid was 718.0 mg/L. Thoracic MRI revealed strip-shaped abnormal signals with remarkable enhancement along the anterior and posterior borders of the dural sac at the T1–T6 levels. Histopathological examination confirmed IgG4-related spinal pachymeningitis. The symptoms worsened rapidly, and surgical resection of the space-occupying lesion in the vertebral canal was performed for spinal decompression. Corticosteroid therapy was administered, and the patient's motor functions were mildly improved. IgG4-related disease can manifest as spinal pachymeningitis and cause spinal cord compression. Clinicians should be aware of this rare condition, and early diagnosis, timely surgical decompression, and appropriate corticosteroid therapy should be highlighted.