Prednisolone markedly reduced serum IgG4 levels along with the improvement of pituitary mass and anterior pituitary function in a patient with IgG4-related infundibulo-hypophysitis

Secondary adrenocortical insufficiency after treatment with retifanlimab: a case report

With advancements in medical oncology, immune checkpoint inhibitors (ICIs) have become the first-line treatment for many malignancies. ICIs play a significant role in improving cancer prognosis, but a series of immune-related adverse events (irAEs), including immune-related endocrine events (irEEs), caused by ICIs have also aroused concerns. Rapid clinical identification of irAEs caused by ICIs is particularly important. We describe a case of secondary adrenocortical insufficiency (AI) after PD-1 treatment in a postoperative patient with endometrial cancer. A 73-year-old female patient developed anorexia, nausea, vomiting, malaise, electrolyte disturbances, ineffective symptomatic treatment, and decreased serum adrenocorticotropin and cortisol levels six months after retifanlimab treatment. The vomiting resolved, and the electrolyte levels were corrected after 3 days of treatment with glucocorticoids (hydrocortisone, intravenous, 200 mg/day). When patients present with gastrointestinal symptoms, such as poor appetite and nausea, not only symptomatic treatment but also a search for the etiology behind the symptoms is needed, especially in immunotherapy patients who should undergo a thorough evaluation of the endocrine system and be alert for adrenocortical insufficiency.

A case of pituitary gland abscess associated with granulomatous hypophysitis

BACKGROUND

Granulomatous hypophysitis is a rare disease that presents with chronic inflammation of the pituitary gland. In this study, we reported a case of granulomatous hypophysitis associated with a pituitary abscess.

CASE PRESENTATION

A 39-year-old woman presented with a 2-year history of infertility. For the past six months, she has suffered from amenorrhea, decreased libido, headaches, and vertigo. She was referred to our hospital with a suspected diagnosis of nonfunctioning pituitary adenoma based on her presentation and brain MRI findings. She underwent trans-sphenoidal surgery (TSS). Direct observation during surgery revealed drainage of malodor pus and pituitary gland abscess. The histopathological evaluation also showed granulomatous hypophysitis and neutrophilic microabscess formation. The patient was initially treated with high doses of ceftriaxone (2 g twice daily) and metronidazole (500 mg (mg) four times per day). Also, the patient received cortisol replacement therapy after the operation. After obtaining the antibiogram and culture results, the treatment regimen was continued for 4 weeks postoperatively, followed by amoxicillin-clavulanate (500/125 mg three times daily) for a total duration of 12 weeks.

CONCLUSION

The patient recovered uneventfully and the postoperative MRI was normal without any remnant lesions.

Enrichment of serum IgG4 in MuSK myasthenia gravis patients

Muscle-specific kinase (MuSK) myasthenia gravis (MG) is a neuromuscular autoimmune disease belonging to a growing group of IgG4 autoimmune diseases (IgG4-AIDs), in which the majority of pathogenic autoantibodies are of the IgG4 subclass. The more prevalent form of MG with acetylcholine receptor (AChR) antibodies is caused by IgG1-3 autoantibodies. A dominant role for IgG4 in autoimmune disease is intriguing due to its anti-inflammatory characteristics. It is unclear why MuSK autoantibodies are predominantly IgG4. We hypothesized that MuSK MG patients have a general predisposition to generate IgG4 responses, therefore resulting in high levels of circulating IgG4. To investigate this, we quantified serum Ig isotypes and IgG subclasses using nephelometric and turbidimetric assays in MuSK MG and AChR MG patients not under influence of immunosuppressive treatment. Absolute serum IgG1 was increased in both MuSK and AChR MG patients compared to healthy donors. In addition, only MuSK MG patients on average had significantly increased and enriched serum IgG4. Although more MuSK MG patients had elevated serum IgG4, for most the IgG4 serum levels fell within the normal range. Correlation analyses suggest MuSK-specific antibodies do not solely explain the variation in IgG4 levels. In conclusion, although serum IgG4 levels are slightly increased, the levels do not support ubiquitous IgG4 responses in MuSK MG patients as the underlying cause of dominant IgG4 MuSK antibodies.

Hypophysitis, the Growing Spectrum of a Rare Pituitary Disease

Hypophysitis is defined as inflammation of the pituitary gland that is primary or secondary to a local or systemic process. Differential diagnosis is broad (including primary tumors, metastases, and lympho-proliferative diseases) and multifaceted. Patients with hypophysitis typically present with headaches, some degree of anterior and/or posterior pituitary dysfunction, and enlargement of pituitary gland and/or stalk, as determined by imaging. Most hypophysitis causes are autoimmune, but other etiologies include inflammation secondary to sellar tumors or cysts, systemic diseases, and infection or drug-induced causes. Novel pathologies such as immunoglobulin G4-related hypophysitis, immunotherapy-induced hypophysitis, and paraneoplastic pituitary-directed autoimmunity are also included in a growing spectrum of this rare pituitary disease. Typical magnetic resonance imaging reveals stalk thickening and homogenous enlargement of the pituitary gland; however, imaging is not always specific. Diagnosis can be challenging, and ultimately, only a pituitary biopsy can confirm hypophysitis type and rule out other etiologies. A presumptive diagnosis can be made often without biopsy. Detailed history and clinical examination are essential, notably for signs of underlying etiology with systemic manifestations. Hormone replacement and, in selected cases, careful observation is advised with imaging follow-up. High-dose glucocorticoids are initiated mainly to help reduce mass effect. A response may be observed in all auto-immune etiologies, as well as in lymphoproliferative diseases, and, as such, should not be used for differential diagnosis. Surgery may be necessary in some cases to relieve mass effect and allow a definite diagnosis. Immunosuppressive therapy and radiation are sometimes also necessary in resistant cases.

[Clinical characteristics of central nervous system involvement in IgG4 related diseases]

OBJECTIVE

To improve the understanding of the clinical characteristics of immunoglobulin G4-related disease (IgG4-RD) with central nervous system (CNS) involvement, so as to contribute to the early diagnosis and treatment.

METHODS

In this study, 10 patients with IgG4-RD with CNS involvement were selected. Clinical data including demographic features, clinical manifestations, organ involvement, laboratory findings, radiological results, pathology, treatments and outcomes were collected retrospectively.

RESULTS

Among the 10 IgG4-RD patients complicated with CNS involvement, 6 cases manifested as pituitary involvement and 4 cases manifested as dural involvement. Only 2 patients had nervous system involvement alone, while the left patients were complicated with other organ involvement besides nervous system. Half of the patients presented nervous system involvement as the initial manifestation, and the main symptoms of nervous system included polydipsia, polyuria, headache, decreased vision and so on. In the laboratory examination, the serum IgG4 level was increased in 9 cases (90.0%), and the total serum IgE was increased in 7 cases (87.5%). At the same time, their IgG, erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) were increased, while complement (C) 3 and C4 were decreased in some patients. Eight patients underwent tissue biopsies in different parts, the pathological examination showed a large number of lymphocyte and plasma cell infiltration, accompanied by fibrous tissue proliferation in part. All the patients were treated with glucocorticoids, and 8 cases (80%) were given immunosuppressants at the same time, and 3 cases were treated with rituximab when they expe-rienced disease relapse. As a result, 2 cases (20%) achieved complete remission (CR), and 8 cases (80%) achieved partial remission (PR). The median follow-up time was 13.5 months, and 4 cases relapsed.

CONCLUSION

Pituitary and dura are common affected organs of IgG4-RD with CNS involvement. Most IgG4-RD patients with CNS involvement are combined with other organ involvement, but half of them presented nervous system involvement as the initial manifestation, and the symptoms are not typical. In order to make an early diagnosis, laboratory, imaging examination and tissue biopsy should be taken into consideration in combination if necessary.

Hypophysitis: A comprehensive overview

Hypophysitis is defined as inflammation of the pituitary gland. It is a heterogeneous condition as it can originate from different parts of the pituitary gland, can be caused by different pathophysiological processes, and can be isolated or the manifestation of a underlying systemic disease. Hypophysitis usually presents with endocrine deficiencies, including diabetes insipidus, with varying patterns. A subset of patients presents with mass effects. The last decades major progress has been made in the understanding of this disease. New forms are now recognized, new diagnostics are being developed, and specific treatments are proposed. This review provides an overview of the current knowledge on hypophysitis using an aetiology-based approach and provides the clinician with a stepwise approach to the patient with (suspected) hypophysitis.

IgG4-related hypophysitis

Hypophysitis is a rare pituitary inflammatory disorder classified in different ways. Immunoglobulin G4-related disease (IgG4-RD), also a rare disease is a systemic fibro-inflammatory condition characterized by infiltration of tissue with IgG4-positive plasma cells; however prevalence of both of them probably is underestimated. In this paper, we present an Iranian patient with biopsy-proven IgG4-related hypophysitis and then review the clinical characteristics, laboratory, imaging, pathologic findings and therapeutic management as well as prognosis of 115 published cases of hypophysitis secondary to IgG4-related disease.

Deterioration of pituitary function without relapse after steroid therapy for IgG4-related hypophysitis

SUMMARY

IgG4-related hypophysitis is an autoimmune hypophysitis associated with IgG4-related disease. Swelling of the pituitary gland is responsive to steroid therapy, but the prognosis of pituitary function after the treatment remains unclear. The present case implies that transiently improved pituitary function can re-worsen during long-term follow-up in IgG4-related hypophysitis. A 71-year-old male patient with IgG4-related hypophysitis visited a nearby hospital with malaise, anorexia, and polyuria. Pituitary dysfunction was suspected, so he was referred to our hospital for further examination. Imaging studies and laboratory data showed swelling of the pituitary gland and panhypopituitarism, which dramatically improved following steroid therapy. There was no evidence of relapsing IgG4-related disease during prednisolone tapering. Pituitary function was examined after 4 years under treatment with low-dose prednisolone; surprisingly, anterior pituitary function had worsened again. Our case suggests a need for continuous monitoring of pituitary function after steroid therapy for IgG4-related hypophysitis. This report illustrates the natural course of pituitary function in IgG4-related hypophysitis and may be informative when considering the introduction of steroid therapy.

LEARNING POINTS

Steroid therapy is an effective first-line therapy for pituitary dysfunction and pituitary swelling in IgG4-related hypophysitis. Pituitary function can worsen again during follow-up, despite transient improvement after steroid therapy in IgG4-related hypophysitis. Continuous monitoring of pituitary function is necessary for IgG4-related hypophysitis, regardless of disease activity.

The neurology of IGG4-related disease

PURPOSE OF REVIEW

IgG4-related disease (IgG4-RD) is emerging as a fibro-inflammatory entity affecting multiple organs, including manifold neurologic manifestations. This review discusses general characteristics of IgG4-RD neurologic disease including epidemiology, histology, clinical picture and treatment approaches.

RECENT FINDINGS

IgG4-RD is increasingly recognized as an important underlying pathophysiology in multiple disorders of neurologic interest, including orbital inflammation, infundibulo-hypophysitis, hypertrophic pachymeningitis, and even in rare cases CNS parenchymal disease and cranial vascular involvement. These were previously considered idiopathic and unrelated to any systemic disease but now known to share a common histopathology. New knowledge regarding the pathogenesis, clinical features and epidemiology of IgG4 is emerging, and new neurological manifestations continue to be described. Diagnostic progress includes CT-PET imaging, the use of flow cytometry for plasmablast quantification, and the use of reverse passive latex agglutination aiming to overcome the prozone phenomenon. Histopathologic confirmation of IgG4-RD remains the gold standard method of diagnosis but new diagnostic criteria for systemic and organ-specific disease are being proposed. Though glucorticoids remain the mainstay of therapy, relapses and incomplete recovery are frequent. Rituximab is a promising treatment in IgG4-RD that is severe, refractory or glucocorticoid dependent. Initiation of immunosuppression at an early stage of disease should be considered in order to avoid development of refractory fibrosis.

SUMMARY

The current review emphasizes the neurologic manifestations of IgG4-RD.

MRI Findings of Immune Checkpoint Inhibitor-Induced Hypophysitis: Possible Association with Fibrosis

BACKGROUND AND PURPOSE

Hypophysitis is one of the well-known adverse effects of immune checkpoint inhibitors. Immune checkpoint inhibitor-induced hypophysitis frequently causes irreversible hypopituitarism, which requires long-term hormone replacement. Despite the high frequency and clinical significance, characteristic MR imaging findings of immune checkpoint inhibitor-induced hypophysitis have not been established. In the present study, we aimed to review and extract the MR imaging features of immune checkpoint inhibitor-induced hypophysitis.

MATERIALS AND METHODS

This retrospective international multicenter study comprised 20 patients with melanoma who were being treated with immune checkpoint inhibitors and clinically diagnosed with immune checkpoint inhibitor-induced hypophysitis. Three radiologists evaluated the following MR imaging findings: enlargement of the pituitary gland and stalk; homogeneity of enhancement of the pituitary gland; presence/absence of a well-defined poorly enhanced area and, if present, its location, shape, and signal intensity in T2WI; and enhancement pattern in contrast-enhanced dynamic MR imaging. Clinical symptoms and hormone levels were also recorded.

RESULTS

Enlargement of the pituitary gland and stalk was observed in 12 and 20 patients, respectively. Nineteen patients showed poorly enhanced lesions (geographic hypoenhancing lesions) in the anterior lobe, and 11 of these lesions showed hypointensity on T2WI. Thyrotropin deficiency and corticotropin deficiency were observed in 19/20 and 12/17 patients, respectively, which persisted in 12/19 and 10/12 patients, respectively, throughout the study period.

CONCLUSIONS

Pituitary geographic hypoenhancing lesions in the anterior lobe of the pituitary gland are characteristic and frequent MR imaging findings of immune checkpoint inhibitor-induced hypophysitis. They reflect fibrosis and are useful in distinguishing immune checkpoint inhibitor-induced hypophysitis from other types of hypophysitis/tumors.

Hypophysitis in the era of immune checkpoint inhibitors and immunoglobulin G4-related disease

INTRODUCTION

Hypophysitis is a rare disorder, defined as inflammation of the pituitary gland that may result in pituitary enlargement and varying anterior and posterior pituitary hormonal deficits. It involves different histopathological subtypes and variable etiologies, with considerable overlap between classification systems. Histopathology is the gold standard diagnostic approach.

AREAS COVERED

In this article, we will review the major histopathological subtypes of hypophysitis with a special focus on immunoglobulin G4 (IgG4)-related hypophysitis and immune checkpoint inhibitor-induced hypophysitis, given their recent appearance and increasing incidence. We will summarize the similarities and differences between the different subtypes as it relates to epidemiology, pathogenesis, presentation, diagnosis, and management.

EXPERT OPINION

Hypophysitis is a heterogeneous and wide term used to describe different, possibly distinct diseases often with poorly understood pathogenesis. It involves a wide range of subtypes with certain differences in incidence rates, pathogenesis, and management. Management usually focuses on relieving the mass effect symptoms and replacing the deficient pituitary hormones. Spontaneous recovery is possible but recurrence is not uncommon.

Idiopathic Granulomatous Hypophysitis with Rapid Onset: A Case Report

Idiopathic granulomatous hypophysitis (IGH), a rare disease, requires differentiation from more common mass lesions of the sella such as pituitary adenoma, craniopharyngioma, Rathke's cleft cyst, or pituitary tuberculoma. IGH usually presents with an insidious onset of visual defects and headaches. On the other hand, rapid onset of neurologic and visual symptoms in an IGH patient is exceptionally rare. Here, we present a biopsy-proven case of IGH with rapid onset and satisfactory outcome after high dose steroid treatment.

New causes of hypophysitis

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

Disease heterogeneity in IgG4-related hypophysitis: report of two histopathologically proven cases and review of the literature

IgG4-related hypophysitis (IgG4-RH) is a rare disease, which can occur singularly or as manifestation of a systemic IgG4-related disease (IgG4-RD). Less than one hundred cases have been reported in the literature, very few of which were histopathologically documented. We analyzed the clinical, radiological, and histopathological features of two cases of IgG4-RH, the former observed in a 66-year-old man in the context of an IgG4-RD, and the latter affecting a 21-year-old woman, as an isolated lesion. In addition, we performed a comprehensive review of the previously published histopathologically documented cases of IgG4-RH. Pituitary samples from both patients showed dense lymphoplasmacytic infiltration, interstitial and storiform fibrosis, and high numbers of IgG4-positive plasma cells, consistent with IgG4-RH. From the literature review, we retrieved 18 papers reporting a total of 22 cases of histopathologically documented IgG4-RH. The revision of these cases, also including the two reported herein, showed an equal distribution of IgG4-RH in the two sexes, albeit significant clinico-pathological variation was found between cases arisen in female and male patients, respectively. In detail, IgG4-RH females were affected in their second-third decade of life, with a solitary pituitary lesion, low IgG4 serum level, and frequent association with autoimmune disorders. By contrast, IgG4-RH in men was a disease of the elderly, often in the context of a systemic IgG4-RD, with high IgG4 serum levels. Our study shows that IgG4-RH, as currently defined, is a clinically heterogenous disease, with different features in the two sexes. Indeed, cases diagnosed in young women, as our case 2, mostly do not present other evidence of IgG4-RD and might be better classified as lymphocytic hypophysitis with abundant IgG4+ plasma cells. For this reason, the histopathological examination of the pituitary lesion, particularly in female patients, may still be useful for a correct differential diagnosis with other variants of primary hypophysitis.

IgG4-related hypophysitis in patients with autoimmune pancreatitis

PURPOSE

IgG4-related disease involves various organs including the pituitary and pancreas. The prevalence of IgG4-related hypophysitis is relatively rare compared with IgG4-related pancreatitis (autoimmune pancreatitis). Although several cases demonstrating both autoimmune pancreatitis and hypophysitis have been reported, the prevalence of IgG4-related hypophysitis in patients with autoimmune pancreatitis remains unknown. This study aimed at screening for IgG4-related hypophysitis to accurately determine its prevalence in patients with autoimmune pancreatitis.

METHODS

In this cohort study, we screened IgG4-related hypophysitis via pituitary magnetic resonance imaging (MRI) and endocrinological examination in 27 patients who were undergoing follow-up for autoimmune pancreatitis at Kobe University Hospital between 2014 and 2018.

RESULTS

Among 27 patients with autoimmune pancreatitis, 5 patients exhibited morphological abnormalities in the pituitary (18.5%). Among them, one patient (3.7%) met the criteria for hypophysitis with an enlarged pituitary and stalk concomitant with hypopituitarism. After glucocorticoid treatment, the enlarged pituitary shrank and became empty sella during the clinical course. Four patients (14.8%) revealed empty sella without obvious pituitary dysfunction. Four of 5 patients with morphological pituitary abnormalities showed multiple organ involvement in addition to pancreatic and pituitary involvement. Accordingly, multiple organ involvement was more prevalent in patients with morphological pituitary abnormalities (80%) compared to those without (48%).

CONCLUSIONS

Although a large-scale study is necessary to validate these results, these data suggest that the prevalence of hypophysitis in patients with autoimmune pancreatitis may be underestimated. Based on our findings, we recommend screening for hypophysitis, especially in patients with multiple organ involvement.

Clinical Characteristics of 76 Patients with IgG4-Related Hypophysitis: A Systematic Literature Review

BACKGROUND

IgG4-related hypophysitis (IgG4-RH) is a rare disease, and its prevalence remains unclear. In recent years, an increasing number of cases have been reported because of the increasing recognition of this disease. We aimed to summarize case reports of IgG4-RH and outline the clinical features and outcomes.

METHODS

We performed PubMed search of articles using the search terms "hypophysitis [AND] IgG4." Consequently, only 54 English articles (76 cases) met Leporati's diagnostic criteria.

RESULTS

Of the 76 cases, the ratio of men to women was 1.5 : 1, and the age at diagnosis was 54.1 ± 17.8 years. The median IgG4 concentration was 405.0 mg/dl. Anterior hypopituitarism, isolated central diabetes insipidus, and panhypopituitarism were observed in 14 (18.4%), 12 (15.8%), and 44 (57.9%) cases, respectively. The sequence of anterior hormone deficiency was as follows: gonadotropin (68.4%), ACTH (63.2%), TSH (59.2%), GH (48.7%), and prolactin (42.1%). The median number of involved organs was 1.5, and the lung (18.4%), retroperitoneum (17.1%), kidney (15.8%), submandibular glands (14.5%), and pancreas (13.2%) were the common involved organs. Elevated IgG4 concentration and normal IgG4 level were in 42 (76.4%) and 13 (23.6%) cases, respectively. Patients with elevated serum IgG4 concentration were older (60.9 ± 14.3 vs 45.6 ± 17.4, p=0.001) and male-prone (78.6% vs 40.4%, p=0.003) and had a susceptibility of multiple organ involvement (78.6% vs 35.0%, p=0.001) compared to those with normal serum IgG4 levels. Males were older at disease onset (61.5 ± 12.6 vs 42.9 ± 18.8, p < 0.001) and had a higher IgG4 concentration (425.0 vs 152.5, p=0.029) and a greater number of involved organs (2.0 vs 0.0, p=0.001), while isolated hypophysitis was more prominent in female (63.3% vs 26.1%, p=0.001).

CONCLUSION

In this review, we found that there were different characteristics between different genders. Patients with elevated serum IgG4 level in terms of some clinical features were also different from those with normal serum IgG4 level. However, the data in this review were limited by bias and confounding. Further clinical studies with larger sample sizes are warranted.

Rituximab treatment for isolated IgG4-related hypophysitis in a teenage female

IgG4-related hypophysitis is an important diagnostic consideration in patients with a pituitary mass or pituitary dysfunction and can initially present with headaches, visual field deficits and/or endocrine dysfunction. Isolated IgG4-related pituitary disease is rare, with most cases of IgG4-related disease involving additional organ systems. We report the case of a teenage female patient with isolated IgG4-related hypophysitis, diagnosed after initially presenting with headaches. Our patient had no presenting endocrinologic abnormalities. She was treated with surgical resection, prednisolone and rituximab with no further progression of disease and sustained normal endocrine function. This case, the youngest described patient with isolated IgG4-related hypophysitis and uniquely lacking endocrinologic abnormalities, adds to the limited reports of isolated pituitary disease. The use of rituximab for isolated pituitary disease has never been described. While IgG4-related hypophysitis has been increasingly recognized, substantial evidence concerning the appropriate treatment and follow-up of these patients is largely lacking. Learning points: IgG4-related hypophysitis most often occurs in the setting of additional organ involvement but can be an isolated finding. This diagnosis should therefore be considered in a patient presenting with pituitary abnormalities. Most patients with IgG4-related hypophysitis will have abnormal pituitary function, but normal functioning does not exclude this diagnosis. Corticosteroids have been the mainstay of therapy for IgG4-related disease, with other immunosuppressive regimens being reserved for refractory cases. Further research is needed to understand the effectiveness of corticosteroid-sparing regimens and whether there is utility in using these agents as first-line therapies.

'Houdini's Pituitary:' A Case Report of Regression of Pituitary Mass to Empty Sella in a 58-Year-Old Man with Autoimmune Hypophysitis

A 58-year-old male presented with persistent severe headache, lethargy, decline libido and no neurological deficits. Besides quadruple anterior pituitary hormonal deficiencies, magnetic resonance imaging (MRI) demonstrated an enlarged ring-enhanced non-homogenous pituitary. Following hormonal replacement, these symptoms improved but empty sella evolved. The challenges of diagnosis and management were discussed. Awareness of the unclear etiology and uncertain clinical course of autoimmune hypophysitis in a man in this age group is essential for prompt and appropriate management.

The autoimmune IgG4 -associated endocrine pathology

Immunoglobulin G4-associated diseases (IgG4-AD) arethe group of chronic progressive autoimmune fibro-inflammatory pathology of various organs and tissues, characterized by their enlargement and abundant infiltration of immunoglobulin G4-positive plasma cells, as well as an increase in the level of serum immunoglobulin G4 (IgG4).In most patients, the disease is characterized by a mild course.However, there is evidence of a high incidence of malignancies in patients with IgG4-AD.Among endocrine IgG4-associated pathologies, pancreatitis with outcome in diabetes mellitus, hypophysitis and thyroiditis are described. Laboratory examination usually reveals an increased level of IgG4. However, the concentration of IgG4 could not be used as the only diagnostic criterion.The possibility of plasmablastsdetermining as a marker of the disease is discussed.Among the imaging techniques CT, MRI and 18F-FDG-PET/CT are used.However, the most informative method of diagnosis is biopsy. Randomized clinical trials to determine clear recommendations for the treatment of IgG4-AD were not conducted.In most cases, glucocorticoids are prescribed, and immunosuppressive therapy is sometimes used.According to the results of recent studies, the genetically engineered drug rituximab is relatively effective in inducing remission of the disease.Given the high recurrence rate and the risk of malignancy, patients with IgG4-AD require careful long-term follow-up. Thus, the review describes the clinical manifestations of IgG4-AD, examines the possibilities of their diagnosis and presents the existing methods of treatment.However, given the fact that IgG4-AD became a separate group of autoimmune pathology less than 20 years ago, there are insufficient data on these diseases. Researches related to epidemiology, pathophysiology, diagnosis and effective treatment of IgG4-AD are actual.

IgG4-related Hypophysitis with Subtle Hypopituitarism in an Elderly Diabetic Patient: Is Treatment or Observation Preferable?

A 70-year-old man with diabetes mellitus presented with an enlarged pituitary stalk in 2014. IgG4-related parotitis and submandibular sialoadenitis were diagnosed in 2012. He denied any symptoms related to a pituitary mass. His visual field was intact, and his hypopituitarism was subtle. The serum IgG4 level was elevated. A lip biopsy revealed strong fibrosis and hyper-infiltration of IgG4-positive plasma cells. Based on these findings, IgG4-related hypophysitis was diagnosed. The patient was carefully followed without specific intervention. His clinical condition showed no change until December 2016, suggesting a stable, natural course. Care should be taken when considering glucocorticoid therapy, especially for elderly diabetic patients, given possible side effects.

Rituximab was used to treat recurrent IgG4-related hypophysitis with ophthalmopathy as the initial presentation: A case report and literature review

RATIONALE

Immunoglobulin G4 (IgG4)-related hypophysitis is a type of IgG4-related disease (IgG4-RD), which is characterized by plasma cells infiltration in the pituitary causing functional changes and (or) space-occupying effect in the pituitary. IgG4-related hypophysitis is sensitive to hormone therapy in most patients, but recurrence is very likely.

PATIENT CONCERNS

Here, we report a 57-year-old male patient with bilateral eye redness as the initial presentation. He later presented with pituitary hypofunction that involved multiple organs, including eyes, lacrimal gland, pituitary, lung, gall bladder, and intestine. There was an elevation of C-reactive protein and blood sedimentation, but the IgG and IgG4 levels of the serum and the cerebrospinal fluid did not increase obviously following irregular glucocorticoid therapy. Magnetic resonance imaging revealed enlarged pituitary and obviously thickened pituitary stalk. IgG4-related hypophysitis was confirmed by biopsy of the pituitary.

DIAGNOSES

The patient was diagnosis of IgG4-related hypophysitis with ophthalmopathy by pathological and molecular tests.

INTERVENTIONS

The patient responded to methylprednisolone pulse therapy but relapsed during the maintenance therapy using small-dose hormones combined with azathioprine. Methylprednisolone pulse therapy was given for 3 days followed by rituximab injection for 4 weeks.

OUTCOMES

After use methylprednisolone pulse therapy with rituximab the patient achieved complete remission.

LESSONS

Rituximab achieved good effect for recurrent IgG4-related hypophysitis after glucocorticoid therapy combined with immunosuppressant in this case. Moreover, comparative analysis was carried out with other reported cases of IgG4-related hypophysitis in terms of clinical features, treatment, and follow-up.

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.

Critical review of IgG4-related hypophysitis

PURPOSE

IgG4-related hypophysitis is a rare disease, with only 34 cases published in English (2015). Available short reviews may not present complete details of IgG4-related hypophysitis. We aimed to survey case reports of IgG4-related hypophysitis, including abstracts of scientific meetings, in English and Japanese.

METHODS

We searched for information about IgG4-related hypophysitis in PubMed and Igakuchuozasshi (Japan Medical Abstracts Society). Among 104 case reports found, we reviewed 84 fulfilling Leporati's diagnostic criteria.

RESULTS

The mean ±  SD age of onset was 64.2  ±  13.9, 67.5  ±  9.8, and 56.4  ±  18.6 years for all subjects, men, and women, respectively. Men:women was 2.4:1. On magnetic resonance imaging, pituitary, stalk, and pituitary-stalk mass were observed at frequencies of 14.3, 21.4, and 64.3%, respectively. Manifestations were anterior hypopituitarism in 26.2% (22 cases), central diabetes insipidus in 17.9% (15 cases), and panhypopituitarism in 52.4% (44 cases). The median level of serum IgG4 was 264.5 mg/dL for all subjects, 405 mg/dL for men, and 226 mg/dL for women. The mean number of IgG4-related systemic diseases was 2.7  ±  1.5 in all subjects, 3.0  ±  1.5 in men, and 1.8  ±  1.1 in women. Among the IgG4-related diseases, retroperitoneal fibrosis was the most frequent (26.2%), followed by salivary gland diseases (25%). Glucocorticoid therapy was generally effective, except for two cases that received replacement doses. There were significant differences between sexes in terms of age, serum IgG4 levels, and number of IgG4-related diseases.

CONCLUSION

IgG4-related hypophysitis may have different clinical characteristics between genders. This survey may lack some information because the Japanese abstracts did not contain certain details.

IgG4-related hypophysitis is highly prevalent among cases of histologically confirmed hypophysitis

IgG4-related disease is an immune-mediated disease with manifestations in most organ systems among them the pituitary gland. To date, few cases of histologically confirmed cases of IgG-related hypophysitis have been reported. The aim of this study was to retrospectively determine the prevalence of IgG4-related hypophysitis among cases previously diagnosed as primary hypophysitis (lymphocytic hypophysitis, granulomatous hypophysitis and hypophysitis not otherwise specified). Histological and immunohistochemical analysis revealed that 12 of 29 cases (41.4%) previously diagnosed as primary hypophysitis fulfilled the criteria for IgG4-related disease and, thus, IgG4-related hypophysitis should always be considered in the differential diagnosis of primary hypophysitis. All cases of IgG4-related hypophysitis showed a dense lymphoplasmacytic infiltrate with more than 10 IgG4-positive cells per high power field and a ratio of IgG4/IgG-positive cells of more than 40%, whereas storiform fibrosis was an inconsistent histological feature and was also seen in few cases of non-IgG-related hypophysitis, thus lacking sensitivity and specificity. Obliterative phlebitis was not seen in any case. Thus, histological criteria defined for IgG4-related disease in other organs should be modified for IgG4-related hypophysitis, accordingly.

Overlap of Post-obstructive Diuresis and Unmasked Diabetes Insipidus in a Case of IgG4-related Retroperitoneal Fibrosis and Tuberoinfundibular Hypophysitis: A Case Report and Review of the Literature

The clinical picture of IgG4-related disease (IgG4-RD) is diverse because various organs can be affected. We describe the case of a 56-year-old man with acute renal failure and tuberoinfundibular hypophysitis due to IgG4-RD. Steroid therapy lowered the serum IgG4 level and ameliorated renal dysfunction, bilateral hydronephrosis and retroperitoneal fibrosis. However, polyuria from post-obstructive diuresis and unmasked central diabetes insipidus ensued. The patient's polyuria continued despite the administration of a therapeutic dose of glucocorticoid; the patient's pituitary swelling and anterior pituitary dysfunction were partially ameliorated. The pituitary swelling recurred seven months later. In patients with IgG4-RD, the manifestation of polyuria after steroid therapy should prompt suspicion of post-obstructive diuresis and the unmasking of central diabetes insipidus.

Clinical course of IgG4-related hypophysitis presenting with focal seizure and relapsing lymphocytic hypophysitis

BACKGROUND

This is the first case report of focal seizure as a manifestation of Immunoglobulin G4 (IgG4)-related hypophysitis. IgG4-related hypophysitis is a novel category of hypophysitis. The clinical presentations, imaging studies and initial pathology studies can mimic lymphocytic hypophysitis. Here we report additional clinical clues in differentiating these two conditions.

CASE PRESENTATION

A 43-year-old Thai male presented with focal seizure, headache, and anterior pituitary hypofunction. His MRI study showed typical hypophysitis lesion with abnormal cerebral parenchymal signal intensity at right frontal lobe. The pituitary biopsied was obtained and the patient was initially diagnosed with lymphocytic hypophysitis. Following initial low-dose steroid therapy, his seizure and headache resolved but his anterior pituitary hormones remained deficient. However, during steroid tapering, he developed new onset acute visual loss. Upon rigorous pathologic review, his diagnosis of IgG4-related hypophysitis with suspected CNS involvement was established. He was subsequently treated with high-dose steroid and rapidly regained his sight.

CONCLUSION

This case report highlights the important distinguishing features of IgG4-related hypophysitis from lymphocytic hypophysitis. These include the relapsing clinical course of hypophysitis after steroid decrement and concomitant pachymeningitis particularly in middle-aged to elderly Asian male who presented with hypophysitis. With appropriate dosage of steroids, medical treatment is usually sufficient to control the disease and surgical interventions are usually not required.

Autoimmune lymphocytic hypophysitis in association with autoimmune eye disease and sequential treatment with infliximab and rituximab

INTRODUCTION

Autoimmune lymphocytic hypophysitis associates predominantly with other autoimmune endocrinopathies and is most commonly treated with glucocorticoids and/or decompressive pituitary surgery. Here we report a new association and treatment modality for lymphocytic hypophysitis.

METHODS

A 52-year-old woman presented with scleritis, uveitis, facial palsy, and central diabetes insipidus, accompanied by thickened pituitary stalk and enlarged pituitary on cranial MRI. Neurosarcoidosis was suspected and treatment with glucocorticoids and methotrexate initiated. Since symptoms persisted, infliximab (a monoclonal antibody that antagonizes tumor necrosis factor alpha) was added to her regimen. The patient initially improved but after 6 months developed recurrent pituitary enlargement, bilateral optic neuritis, and panhypopituitarism. To ascertain the nature of the pituitary lesion, she underwent transsphenoidal biopsy, which revealed lymphocytic hypophysitis with numerous CD20 positive B lymphocytes. The pathological finding suggested to us that administration of rituximab (a monoclonal antibody that lyzes B cells expressing CD20) could be useful. Following two courses of rituximab, the pituitary mass resolved and the corticotroph axis partially recovered. The patient has remained in remission during 3 years of follow up.

CONCLUSION

This is the first report of hypophysitis occurring with the triad of scleritis, uveitis, and optic neuritis, as well as the first immunotherapy based on the sequential use of infliximab and rituximab.

Histologically confirmed isolated IgG4-related hypophysitis: two case reports in young women

IgG4-related hypophysitis is a recently described entity belonging to the group of IgG4-related diseases. Many other organs can also be affected, and it is more common in older men. To date, 32 cases of IgG4-related hypophysitis have been reported in the literature, 11 of which included confirmatory tissue biopsy and the majority affecting multiple organs. The aim of this report is to present two cases of biopsy-proven IgG4-related hypophysitis occurring in two young female patients with no evidence of involvement of other organs at the time of diagnosis.

LEARNING POINTS

IgG4-related hypophysitis belongs to the group of IgG4-related diseases, and is a fibro-inflammatory condition characterized by dense lymphoplasmacytic infiltrates rich in IgG4-positive plasma cells and storiform fibrosis.It is more common in older men, but young women may also present this type of hypophysitis.Although involvement of other organs is frequent, isolated pituitary disease is possible.Frequent clinical manifestations include anterior hypopituitarism and/or diabetes insipidus.THE DIAGNOSIS MAY BE CONFIRMED WITH ANY OF THE FOLLOWING CRITERIA: a pituitary biopsy with lymphoplasmacytic infiltrates, with more than ten IgG4-positive cells; a sellar mass and/or thickened pituitary stalk and a biopsy-proven involvement of another organ; a sellar mass and/or thickened pituitary stalk and IgG4 serum levels >140 mg/dl and sellar mass reduction and symptom improvement after corticosteroid treatment.Glucocorticoids are recommended as first-line therapy.