Immunoglobulin G4-related gastrointestinal diseases, are they immunoglobulin G4-related diseases?

Gastric IgG4-related disease mimicking a gastrointestinal stromal tumor in a child: A case report

BACKGROUND

Gastric IgG4-related disease (IgG4-RD) is rarely encountered in clinical practice, and especially more so among pediatric patients. To our knowledge, this is the first report of IgG4-RD presenting as a calcifying gastric mass in a child. We describe how this entity was difficult to differentiate from a gastrointestinal stromal tumor (GIST) imaging-based approaches. Therefore, this case highlights the importance of considering IgG4-RD in the differential diagnosis of gastric tumor before performing surgical resection, especially to distinguish it from malignancy to avoid unnecessary surgery.

CASE SUMMARY

The patient suffered from epigastric pain for several days. Panendoscopy and computed tomography scan revealed a submucosal tumor. Differential diagnoses included GIST, leiomyoma, teratoma, and mucinous adenocarcinoma. However, laparoscopic proximal gastrectomy allowed for the definitive diagnosis of IgG4-related stomach disease.

CONCLUSION

We emphasize the importance of considering IgG4-RD in the differential diagnosis of gastric submucosal tumors before performing surgical resection.

Immunoglobulin G4-Related Disease of the Intestine: A Clinicopathological Entity to Be Considered

Background and Objectives: Immunoglobulin G4-related disease (IgG4-RD) is a recently recognized immune-mediated, systemic condition of unknown etiology, associated with fibroinflammatory lesions. Diagnosis is set in the presence of IgG4-positive plasma cell infiltration of the involved tissue and elevated serum IgG4 levels. However, approximately 30% of patients have normal serum IgG4 levels. IgG4-RD may affect several organs, including the pancreas, bile ducts, mesentery, retroperitoneum, and salivary glands, but the involvement of the gastrointestinal tract is uncommon. Materials and Methods: The case series of 4 patients with IgG4-RD involving the intestinal tract was observed in the period of 2017-2022. Colorectal and ileal biopsy specimens were stained with hematoxylin and eosin and immunohistochemical techniques using monoclonal antihuman IgG4 primary antibody. Diagnosis of IgG4-RD was based on the presence of >50 cells/ HPF and IgG4/IgG ratio >40 confirmed by two pathologists. Results: IgG4-RD was set in patients previously diagnosed as affected by Crohn's disease. Conclusions: Systematic IgG4 immunohistochemical staining should be considered in the diagnostic workup of patients with gastrointestinal strictures, mimicking Crohn's disease. The exact prevalence of the condition is likely more frequent than reported and should be defined by a large series of consecutive patients.

[A case of duodenal ulcer as prominent manifestation of IgG4-related disease]

A case of IgG4-related disease presented with a duodenal ulcer to improve the understan-ding of IgG4-related diseases was reported. A 70-year-old male presented with cutaneous pruritus and abdominal pain for four years and blackened stools for two months. Four years ago, the patient went to hospital for cutaneous pruritus and abdominal pain. Serum IgG4 was 3.09 g/L (reference value 0-1.35 g/L), alanine aminotransferase 554 U/L (reference value 9-40 U/L), aspartate aminotransferase 288 U/L (reference value 5-40 U/L), total bilirubin 54.16 μmol/L (reference value 2-21 μmol/L), and direct bilirubin 29.64 μmol/L (reference value 1.7-8.1 μmol/L) were all elevated. The abdominal CT scan and magnetic resonance cholangiopancreatography indicated pancreatic swelling, common bile duct stenosis, and secondary obstructive dilation of the biliary system. The patient was diagnosed with IgG4-related disease and treated with prednisone at 40 mg daily. As jaundice and abdominal pain improved, prednisone was gradually reduced to medication discontinuation. Two months ago, the patient developed melena, whose blood routine test showed severe anemia, and gastrointestinal bleeding was diagnosed. The patient came to the emergency department of Beijing Hospital with no improvement after treatment in other hospitals. Gastroscopy revealed a 1.5 cm firm duodenal bulb ulcer. After treatment with omeprazole, the fecal occult blood was still positive. The PET-CT examination was performed, and it revealed no abnormality in the metabolic activity of the duodenal wall, and no neoplastic lesions were found. IgG4-related disease was considered, and the patient was admitted to the Department of Rheumatology and Immunology of Beijing Hospital for further diagnosis and treatment. The patient had a right submandibular gland mass resection history and diabetes mellitus. After the patient was admitted to the hospital, the blood test was reevaluated. The serum IgG4 was elevated at 5.44 g/L (reference value 0.03-2.01 g/L). Enhanced CT of the abdomen showed that the pancreas was mild swelling and was abnormally strengthened, with intrahepatic and extrahepatic bile duct dilation and soft tissue around the superior mesenteric vessels. We pathologically reevaluated and stained biopsy specimens of duodenal bulbs for IgG and IgG4. Immunohistochemical staining revealed remarkable infiltration of IgG4-positive plasma cells into duodenal tissue, the number of IgG4-positive cells was 20-30 cells per high-powered field, and the ratio of IgG4/IgG-positive plasma cells was more than 40%. The patient was treated with intravenous methylprednisolone at 40 mg daily dosage and cyclophosphamide, and then the duodenal ulcer was healed. IgG4 related disease is an immune-medicated rare disease characterized by chronic inflammation and fibrosis. It is a systemic disease that affects nearly every anatomic site of the body, usually involving multiple organs and diverse clinical manifestations. The digestive system manifestations of IgG4-related disease are mostly acute pancreatitis and cholangitis and rarely manifest as gastrointestinal ulcers. This case confirms that IgG4-related disease can present as a duodenal ulcer and is one of the rare causes of duodenal ulcers.

Gastric linitis plastica with autoimmune pancreatitis diagnosed by an endoscopic ultrasonography-guided fine-needle biopsy: A case report

BACKGROUND

Gastric linitis plastica (GLP) is a subset of gastric cancer with a poor prognosis. It is difficult to obtain a definitive diagnosis by endoscopic mucosal biopsies, and the usefulness of an endoscopic ultrasonography-guided fine-needle biopsy (EUS-FNB) for GLP has been recently reported. Meanwhile, autoimmune diseases are occasionally known to coexist with malignant tumors as paraneoplastic syndrome. We herein report the usefulness of an EUS-FNB for detecting GLP and the possibility of paraneoplastic syndrome coexisting with GLP.

CASE SUMMARY

An 81-year-old man was admitted to our hospital for a 1-mo history of epigastric pain that increased after eating. His laboratory data revealed high levels of serum carbohydrate antigen 19-9 and immunoglobulin-G4. Endoscopic examinations showed giant gastric folds and reddish mucosa; however, no epithelial changes were observed. The gastric lumen was not distensible by air inflation, suggesting GLP. Computed tomography showed the thickened gastric wall, the diffuse enlargement of the pancreas, and the peripancreatic rim, which suggested autoimmune pancreatitis (AIP) coexisting with GLP. Because the pathological findings of the endoscopic biopsy showed no malignancy, he underwent an EUS-FNB and was diagnosed with GLP. He received chemotherapy for unresectable gastric cancer due to peritoneal metastasis, after which both the gastric wall thickening and diffuse enlargement of the pancreas were improved.

CONCLUSION

An EUS-FNB for GLP with a negative endoscopic biopsy is useful, and AIP may develop as a paraneoplastic syndrome.

Clinicopathological characteristics of gastric IgG4-related disease: Systematic scoping review

BACKGROUND AND AIM

Gastric IgG4-related disease (IgG4-RD) can mimic malignancy, submucosal tumors (SMT), and ulcers, leading to over-triage and unnecessary medical interventions such as gastrectomy. The variability in the clinicopathological presentation of IgG4-related disease is not yet well defined, posing a diagnostic challenge.

METHODS

Following the PRISMA Extension for Scoping Reviews, we searched MEDLINE and EMBASE for all peer-reviewed articles using keywords including "gastritis," "stomach," "gastrointestinal stromal tumor," and "IgG4-RD" from their inception to December 28, 2021.

RESULTS

Thirty-nine articles, including 2 observational studies and 42 cases, were included in the systematic review. While bottom-heavy lymphoplasmacytic mucosal infiltration is a characteristic finding of gastric IgG4-RD, it was only present in less than half of the patients in the observational studies. Patients with gastric IgG4-RD were more likely to be diagnosed with gastrointestinal stromal tumor (GIST), gastric cancer, or peptic ulcer disease and their clinical course involved resection (51.3%) or even gastrectomy. Diagnosis of gastric IgG4-RD was most frequently made by post-operative pathological analysis.

CONCLUSION

This systematic review summarizes the current understanding of the characteristics of gastric IgG4-RD. Increased awareness of gastric IgG4-RD as a differential diagnosis of gastric SMT or ulcers among clinicians is crucial in order to reduce unnecessary high-risk, invasive interventions.

Immunoglobulin G4‐related disease accompanying a small intestinal ulcer: A case

Immunoglobulin (Ig)G4‐related disease (IgG4‐RD) is a systemic condition associated with fibroinflammatory lesions and is characterized by elevated serum IgG4 levels and IgG4‐positive cell infiltration into the affected tissues. It has been reported that IgG4‐RD affects a variety of organs but uncommonly affects the gastrointestinal tract. In particular, there are few cases of lesions in the small intestine, except for sclerosing mesenteritis, which were mostly diagnosed from surgical specimens. Herein, we describe the case of a 70‐year‐old man who initially presented with abdominal pain, headache, later cognitive decline, and gait disturbance caused by IgG4‐RD. Colonoscopy revealed irregular ulcers in the terminal ileum, and computed tomography of the head showed hypertrophic pachymeningitis. Numerous IgG4‐positive cells were detected in the ileal and dural biopsies. We diagnosed the patient with IgG4‐RD and started steroid pulse therapy. After initiation of treatment, the symptoms quickly improved. The patient was discharged from the hospital after starting oral prednisolone treatment (30 mg). The dosage was gradually reduced to 10 mg. A follow‐up colonoscopy revealed scarring of the ileal ulcers. This case may provide valuable information regarding the endoscopic findings of small intestinal lesions in IgG4‐RD.

IgG4-related diseases of the digestive tract

IgG4-related conditions affecting the digestive tract are part of a multi-organ fibro-inflammatory disorder termed IgG4-related disease (IgG4-RD), with autoimmune pancreatitis and IgG4-related cholangitis being the most prominent manifestations. Gastrointestinal symptoms include jaundice, weight loss, abdominal pain, biliary strictures, and pancreatic and hepatic masses that mimic malignant diseases. IgG4-RD manifestations occur less frequently elsewhere in the digestive tract, namely in the oesophagus, retroperitoneum or intestine. Evidence-based European guidelines frame the current state-of-the-art in the diagnosis and management of IgG4-related digestive tract disease. Diagnosis is based on histology (if available), imaging, serology, other organ involvement and response to therapy (HISORt criteria). Few biomarkers beyond serum IgG4 concentrations are reliable. The first-line therapy (glucocorticoids) is swiftly effective but disease flares are common at low doses or after tapering. Second-line therapy might consist of other immunosuppressive drugs such as thiopurines or rituximab. Further trials, for example, of anti-CD19 drugs, are ongoing. Although an association between IgG4-RD and the development of malignancies has been postulated, the true nature of this relationship remains uncertain at this time.

Immunoglobulin G4-related Disease: A New Systemic Disease Emerging in Japan

Immunoglobulin G4-related disease (IgG4-RD) is a fibro-inflammatory disease characterized by organ enlargement and elevated serum IgG4 levels. In 2003, IgG4-RD was proposed as a distinct form of IgG4-related systemic disease based on a histopathological study involving patients with autoimmune pancreatitis. IgG4-RD occurs mainly in older men and can affect almost any organ simultaneously or metachronously. Pathophysiologically, IgG4-RD occurs when an autoantigen triggers an immune response characterized by Th2 predominance with increased production of cytokines, such as interleukin 4 (IL-4), IL-5, IL-10, IL-13, and tumor growth factor-β (TGF-β), in the affected organ. IL-10 and TGF-β produced by the increased number of regulatory T cells induce a switch from B cells to IgG4-producing plasma cells and fibrosis, respectively. The characteristic histological features consist of dense infiltration of lymphocytes and IgG4-positive plasma cells, storiform fibrosis, and obliterative phlebitis. IgG4-RD is diagnosed based on a combination of clinical, serological, radiological, and histopathological findings. Differentiating IgG4-RD from malignant tumors or similar inflammatory diseases in the affected organs is important. The 2019 America College of Rheumatology/European League against Rheumatism classification criteria for IgG4-RD have high diagnostic sensitivity and specificity. IgG4-RD generally responds well to treatment with steroids, and a swift response is reassuring and provides further diagnostic confirmation. However, relapses are common during tapering or after cessation of steroids. In Japan, low-dose steroid maintenance therapy is usually given to prevent a relapse. B-cell depletion with rituximab is effective in patients resistant to or dependent on steroids. Most patients with IgG4-RD who receive steroid therapy show good short-term clinical, morphological, and functional outcomes. However, long-term outcomes, such as relapse, fibrosis development, and associated malignancies, have not been clearly defined. Therefore, novel treatment strategies, including rituximab, need to be tested in international randomized controlled clinical trials.

[Immunohistochemical signs of IgG4-related disease in patients with inflammatory bowel diseases]

OBJECTIVE

To determine immunohistochemical features of IgG4-related disease in patients with inflammatory bowel diseases (IBD).

MATERIAL AND METHODS

Immunohistochemical testing of colonic biopsy material from 35 patients with IBD (24 cases of ulcerative colitis and 11 cases of Crohn's disease) was carried out using IgG, IgG4 and CD138 antibodies. The number of IgG4- and CD138-positive cells was counted in high power field of microscope (×400). Patient selection was random.

RESULTS

IgG4-positive cells were detected in the colonic mucosa of 5 patients with ulcerative colitis. The age of the patients ranged from 24 to 47 years. Two patients had a total, and three had a left-sided lesion of the colon. The anamnesis of the disease ranged from 3 to 13 years. The number of positively stained cells in the reaction with the antibody to IgG4 varied from 2 to 50 in high power field of microscope. We were able to detect over 10 IgG4-positive cells in 3 females aged 28, 30 and 31 years with a long history of ulcerative colitis (5, 4 and 3 years, respectively). Two patients had a total lesion of the colon, all three had an exacerbation of the disease, and a morphological study revealed chronic diffuse active erosive colitis. A high degree of histological activity and pronounced diffuse basal plasmacytosis were noted. In one of the cases, the infiltrate captured the muscular lamina of the mucosa and areas of the submucosa.

CONCLUSIONS

IgG4-positive cells in the inflammatory infiltrate, including those with an excess of more than 10 in the field of view of the microscope at high magnification, can be observed in patients with ulcerative colitis with severe and prolonged course of the disease. To classify this colitis as a manifestation of an IgG4-related disease, the results of immunohistochemical studies alone are not enough. It is required to accumulate a larger number of observations, as well as to search for other diagnostic criteria for an IgG4-related disease in these patients.

Autoimmune Pancreatitis with Gastric Cancer: Some IgG4-related Diseases May Be Paraneoplastic Syndrome

A 70-year-old man was referred to our department for the treatment of early gastric cancer. Contrast-enhanced computed tomography (CT) incidentally showed diffuse enlargement of the pancreas with a capsule-like rim, and blood tests showed elevated serum IgG4 levels, leading to a diagnosis of autoimmune pancreatitis (AIP). Endoscopic treatment for gastric cancer was performed, and pathological findings showed adenocarcinoma with abundant IgG4-positive plasma cell infiltration. Thereafter, the serum IgG4 levels normalized, and the findings of AIP disappeared on CT without steroid treatment. These findings suggest that the gastric cancer activated an IgG4-related immune response, resulting in the development of AIP.

Autoimmune Diseases of Digestive Organs-A Multidisciplinary Challenge: A Focus on Hepatopancreatobiliary Manifestation

It is well known that some pathological conditions, especially of autoimmune etiology, are associated with the HLA (human leukocyte antigen) phenotype. Among these diseases, we include celiac disease, inflammatory bowel disease, autoimmune enteropathy, autoimmune hepatitis, primary sclerosing cholangitis and primary biliary cholangitis. Immunoglobulin G4-related diseases (IgG4-related diseases) constitute a second group of autoimmune gastrointestinal, hepatobiliary and pancreatic illnesses. IgG4-related diseases are systemic and rare autoimmune illnesses. They often are connected with chronic inflammation and fibrotic reaction that can occur in any organ of the body. The most typical feature of these diseases is a mononuclear infiltrate with IgG4-positive plasma cells and self-sustaining inflammatory response. In this review, we focus especially upon the hepatopancreatobiliary system, autoimmune pancreatitis and IgG4-related sclerosing cholangitis. The cooperation of the gastroenterologist, radiologist, surgeon and histopathologist is crucial for establishing correct diagnoses and appropriate treatment, especially in IgG4 hepatopancreatobiliary diseases.

IgG4-related disease as a rare cause of gastric outlet obstruction: a case report and literature review

Background

IgG4-related disease involvement of the digestive tract is very rare. In few reported cases of isolated gastric/duodenal IgG4-related disease, none of which resulted in luminal obstruction.

Case presentation

A 59 years old female presented with longstanding gastrointestinal symptoms. CT showed mural thickening of the proximal duodenum. Gastroscopy showed antral ulcer extending into the duodenum with outlet obstruction and biopsy showed acute on chronic duodenitis. Whipple’s procedure was performed and IgG4-related disease was diagnosed on final pathology. Symptoms were revolved on mycophenolate mofetil and prednisone with no recurrence.

Conclusions

Our case is the only reported case with gastric outlet obstruction secondary to gastroduodenal IgG4-related disease. The diagnosis should be considered in the differential diagnosis of unexplained duodenal stricture, gastric outlet obstruction or gastrointestinal ulceration. IgG4-related disease usually responds to steroids but long-term response rates to steroid-sparing agents, especially in the subset of patients with luminal IgG4-related disease remains to be determined.

Immunoglobulin G4-related gastric pseudotumor - An impostor: Case report

INTRODUCTION

Gastric pseudotumors are rare entities whose clinical presentation resembles typical gastric neoplasias, often making them unrecognized unless other causes are considered.

PRESENTATION OF CASE

We present a case report of a patient that debuts with dysphagia, with an abdominal computed axial tomography (CAT) scan revealing a mass at the gastro-esophageal junction suggestive of malignant origin, with studies revealing it to be Immunoglobulin G4-related (IgG4).

DISCUSSION

The diagnosis and identification of IgG4-related gastric pseudotumors is very complicated, often and most commonly an incidental diagnosis upon histologic analysis, as is the situation in this case.

CONCLUSION

Understanding its clinical course and early diagnosis can reduce unwarranted surgical intervention in some patients with IgG4-related disease.

[IgG4-related disease: what do we know after 20 years]

IgG4-related disease is immunomediated fibroinflammatory condition, characterized by tumefective lesions in different organs with distinctive pathomorphological features and IgG4 hypersecretion in serum and tissues in the majority of patients. IgG4-RD has been established as a separate clinical in the early 2000s. In the review we focus on the evolution of views on ethiopathogenesis of the disease, therapeutic and diagnostic options and classification of the disease.

Gastric IgG4-related disease presenting as a mass lesion and masquerading as a gastrointestinal stromal tumor

IgG4-related disease of the stomach is a rare disorder, and only a few cases have been reported. We present two cases that were identified over a 2-month period in our center. Two male patients aged 52 and 48 years presented with mass lesion in the stomach, which were clinically thought to be gastrointestinal stromal tumor, and they underwent excision of the lesion. Microscopic examination revealed marked fibrosis, which was storiform in one case, associated with diffuse lymphoplasmacytic infiltration and an increase in IgG4-positive plasma cells on immunohistochemistry. Serum IgG4 level was markedly elevated. Although rare, IgG4-related disease should be considered in the differential diagnosis of gastric submucosal mass lesions.

Orbital inflammation and colitis in pediatric IgG4-related disease: A case report and review of the literature

IgG4-related disease (IgG4-RD) is an inflammatory disorder characterized by tumor-like swelling in one or more organs, elevated serum IgG4 levels, and histological alterations with infiltration of IgG4-positive plasma cells. IgG4-RD is rare and likely underdiagnosed in children. We report a case of a 16-year-old girl with IgG4-positive colitis that developed weeks after IgG4-related ophthalmic disease and discuss diagnosis and treatment in the context of the literature available. Since the pathophysiology of IgG4-RD is unknown, treatment options are empiric and, for the most part, untargeted. Systemic corticosteroid treatment is the basis of anti-inflammatory treatment in IgG4-RD and induced early remission in our patient. During corticosteroid taper, the patient developed weight loss and intestinal inflammation. Histopathological assessment of the intestinal walls confirmed IgG4-positive colitis. Immune-modulating treatment with non-biologic (e.g., methotrexate (MTX) and mycophenolate mofetil) or biologic (rituximab) disease-modifying antirheumatic drugs has been reported in treatment refractory or corticosteroid-dependent patients. The patient responded to treatment with anti-inflammatory therapy with food rich in TGF-β2 (modulen) and MTX. This is one of the first pediatric patients reported with IgG4-related colitis extending the phenotype of pediatric IgG4-RD. International collaboration to prospectively document clinical presentation and treatment responses may help to further establish the phenotype and treatment options and to raise awareness for IgG4-RD.

Review of IgG4-related disease

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

Gastric calcifying fibrous tumor suspected to be complicated with immunoglobulin G4-related disease treated by laparoscopy and endoscopy cooperative surgery: a case report

Background

Calcifying fibrous tumor (CFT) is a rare benign soft tissue lesion.

Case presentation

A 30-year-old woman was admitted to our hospital with complaints of epigastralgia. A 15-mm submucosal tumor was identified in the greater curvature of the superior body of the stomach by upper gastrointestinal endoscopy. Endoscopic ultrasonography revealed a hypoechoic lesion with an acoustic shadow consistent with calcification. Computed tomography showed a gastric tumor with calcification. A gastrointestinal stromal tumor was diagnosed, and gastric wedge resection was performed by laparoscopy and endoscopy cooperative surgery. On pathological examination, the tumor was identified to be a CFT. Postoperative serum IgG4 levels were 26.0 mg/dl, which supported the diagnosis of probable immunoglobulin G (IgG) 4-related disease, according to the comprehensive diagnostic criteria of IgG4-related disease. The patient was discharged on postoperative day 7 and remains well with no evidence of tumor recurrence for 2 years after resection.

Conclusion

We herein reported a patient with a gastric CFT suspected to be complicated with immunoglobulin G4-related disease that was successfully treated by laparoscopy and endoscopy cooperative surgery.

Calcifying fibrous tumor of the mediastinum: A case report

BACKGROUND

Calcifying fibrous tumor (CFT) is a rare benign mesenchymal tumor that often occurs in deep soft tissue of children and young adults. CFT rarely occurs in the mediastinum.

CASE SUMMARY

In this paper, we describe a 31-year-old male patient with CFT in the mediastinum. The patient did not have any symptoms, and the posterior mediastinal lesion was unintentionally found during routine re-examination of thyroid cancer. The tumor had no adhesion to the surrounding tissue and was successfully and completely removed. Pathology showed a large amount of collagen-rich fibrous connective tissue. There was scattered dystrophic calcification and gravel in the fibrous tissue and a small amount of lymphocyte and plasma cell infiltration and lymphoid follicle formation in the interstitial fluid. In addition, findings showed 20 IgG4+ plasma cells per high-powered field of the diseased tissue, an IgG4+/IgG ratio of about 20%, and normal serum IgG4 levels. The final diagnosis was CFT of the mediastinum (CFTM). No evidence of tumor recurrence was observed by computed tomography at 3 mo after surgery.

CONCLUSION

IgG4+ plasma cell enlargement may occur in CFTM, but clinical manifestations and serological tests suggest that it is not IgG4-related disease. We speculate that it may be an independent tumor subtype.

Gastrointestinal and Extra-Intestinal Manifestations of IgG4-Related Disease

IgG4-related disease (IgG4-RD) is a chronic relapsing multi-organ fibro-inflammatory syndrome of presumed autoimmune etiology. It is characterized by increased serum levels of IgG4 and tissue infiltration by IgG4⁺ cells. Increased titers of autoantibodies against a spectrum of self-antigens and response to steroids have led to its characterization as an autoimmune disease. However, the pathognomonic antigens probably differ among manifestations, and different antigens or autoantibodies produce similar immune reactions in different organs. Little is known about the pathogenic effects, if any, of serum IgG4 or IgG4⁺ plasma cells in tissues. Despite several animal models of the disease, none truly recapitulates human IgG4-RD. Histologic analyses of tissues from patients with IgG4-RD reveal a dense lymphoplasmacytic infiltrate rich in IgG4⁺ plasma cells, storiform fibrosis, and obliterative phlebitis, although these features vary among organs. Typical presentation and imaging findings include mass-forming synchronous or metachronous lesions in almost any organ, but most commonly in the pancreas, bile duct, retroperitoneum, kidneys, lungs, salivary and lacrimal glands, orbit, and lymph nodes. In all organs, inflammation can be reduced by corticosteroids and drugs that deplete B cells, such as rituximab. Patients with IgG4-RD have relapses that respond to primary therapy. Intense fibrosis accompanies the inflammatory response, leading to permanent organ damage and insufficiency. Death from IgG4-RD is rare. IgG4-RD is a multi-organ disease with predominant pancreatico-biliary involvement. Despite its relapsing-remitting course, patients have an excellent prognosis.

A rare presentation of IgG4 related disease as a gastric antral lesion: Case report and review of the literature

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IgG4RD is a newly recognized systemic disease affecting nearly every organ.

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IgG4RD presenting as a gastric mass is extremely rare.

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Preoperative biopsy is mandatory for definitive diagnosis.

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When diagnosed before surgery, the treatment is medical with IV steroids.

Introduction

Immunoglobulin G4 related disease is a recently recognized systemic fibro-inflammatory disorder affecting virtually every organ in the body, characterized by lympho-plasmacytic dense infiltrates rich in IgG4 positive plasmacytes along with storiform fibrosis, inconstantly associated with elevated serum IgG4 levels. Few cases of Immunoglobulin G4 related disease occurring solely in the stomach have been published.

Presentation of case

We herein present a rare case of a 57 year old male patient presenting with an incidentally discovered asymptomatic pre-pyloric submucosal gastric lesion confused with a gastro-intestinal stromal tumor with failed endoscopic biopsy attempts due to tumor mobility. The patient underwent wedge resection of the lesion which was diagnosed postoperatively as Immunoglobulin G4 related disease.

Discussion

Immunoglobulin G4 related disease presenting as a solitary lesion in the stomach is a very rare condition. It should be kept in the differential diagnosis of a submucosal mass or polyp. The treatment is medical with systemic steroid therapy.

Conclusion

Obtaining a tissue biopsy is of extreme importance to avoid unnecessary surgery.

Multivisceral IgG4-related disease presenting as recurrent massive gastrointestinal bleeding: a case report and literature review

Background

IgG4-related disease (IgG4-RD) is a newly recognized autoimmune systemic disorder characterized by elevated levels of serum IgG4 and abundant infiltration of IgG4-positive plasmacytes in the affected organs. The liver, biliary system and pancreas are the most commonly affected organs. However, involvement of the digestive tract is very rare. To date, only a few cases of isolated gastric IgG4-RD have been reported.

Case presentation

We present a case of IgG4-RD of the liver, gallbladder, pancreas and duodenum, which was clinically misinterpreted and thereafter over-treated. A 52-year-old male presented with obstructive jaundice for 3 years, melena for 5 months and hematemesis for 10 days. Three years prior, the patient had undergone biopsies of pancreatic lesions, liver lesions, cholecystectomy and choledochojejunostomy. Histopathology showed chronic inflammatory changes. Endoscopy at admission revealed a duodenal ulcer with active bleeding. Despite medical management, the patient presented with repeated gastrointestinal bleeding. Upon evaluation, serum IgG4 levels were found to be elevated. Histopathology of the duodenal ulcer biopsy and repeated examination of the gallbladder and pancreatic and liver biopsies confirmed IgG4 positive plasma cell infiltration. A definitive diagnosis of IgG4-RD was made and steroid administration was initiated. At last follow up, 11 months to-the-day after initiating steroid treatment, the patient was asymptomatic.

Conclusions

Notably, IgG4-RD of multiple digestive organs is still very rare. As a systemic disease, it is characterized by the infiltration of IgG4-bearing plasma cells and raised IgG4 levels. Histopathology findings remain the diagnostic gold standard for this disorder.

The Clinicopathologic Spectrum of IgG4-Related Disease

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

Sclerosing Esophagitis with IgG4-positive Plasma Cell Infiltration

The patient was a 76-year-old woman who had noticed slight difficulty in swallowing in the 3 years prior to this presentation. Her dysphagia progressed while she was hospitalized following cervical cancer surgery. Esophagogastroduodenoscopy and an esophagram showed circumferential erosion and a stricture of the thoracic esophagus. Esophageal resection was performed; the resected specimens showed a stricture and wall thickening. Histologically, transmural hyperplasia, which consisted of inflammatory granulation tissue with the abundant infiltration of IgG4-positive plasma cells and lymphocytes, was observed. The patient was diagnosed with probable IgG4-related disease. IgG4-related esophageal disease presenting as esophageal lesions alone is a very rare condition.

A rare case of IgG4-related disease: a gastric mass, associated with regional lymphadenopathy

BACKGROUND

IgG4-related disease (IgG4-RD) is a newly recognized disorder, characterized by massive IgG4+ lymphocyte and plasma cell infiltration, storiform fibrosis, causing enlargement, nodules or thickening of the various organs, simultaneously or metachronously. Involvement of the gastrointestinal tract is very rare and can be presented as a diffuse wall thickening or polyp or mass-like lesion. Up to now, there have been reported only a few cases of isolated gastric IgG4-RD.

CASE PRESENTATION

We present an unusual case of IgG4-RD of the stomach with involvement of the regional lymph nodes, clinically manifested as a gastric cancer with related pyloric stenosis. The patient underwent distal gastrectomy, omentectomy and lymph node dissection. The postoperative serum IgG4 level was increased. The diagnosis was confirmed by immunohistochemical study.

CONCLUSIONS

In the most of the reported cases there was not sufficient data about the regional lymph nodal status, although the majority of the patients had been operated with presumptive diagnosis of gastric neoplasm. Our case is rare and valuable because it presents a gastric IgG4-related lesion larger than all previously reported in literature, and IgG4-related lymphadenopathy, confirmed histologically, which contributes to better knowledge of the disease.

Appendiceal Immunoglobulin G4-Related Disease Mimicking Appendiceal Tumor or Appendicitis: A Case Report

Immunoglobulin G4 (IgG4)-related disease is an autoimmune disease that forms tumorous lesions. Several cases involving various organs are reported, however, IgG4-related disease involving appendix has not been reported yet. In this report, we presented a case of IgG4-related disease of appendix, which raised a suspicion of appendiceal tumor or usual appendicitis and, therefore, led to unnecessary surgical resection. IgG4-related disease should be considered in the differential diagnosis for a mass-like swelling of the appendix, in order to avoid unnecessary surgery.

IgG4-Related Disease Presented as a Mural Mass in the Stomach

Isolated gastric IgG4-related disease (IgG4-RD) is a very rare tumefactive inflammatory condition, with only a few cases reported to date. A 48-year-old woman was incidentally found to have a subepithelial tumor in the stomach. Given a presumptive diagnosis of gastrointestinal stromal tumor or neuroendocrine tumor, she underwent wedge resection. The lesion was vaguely nodular and mainly involved the submucosa and proper muscle layer. Microscopically, all classical features of type I autoimmune pancreatitis including lymphoplasmacytic infiltration, storiform fibrosis, obliterative phlebitis, and numerous IgG4-positive plasma cells were seen. She had no evidence of IgG4-RD in other organs. Although very rare, IgG4-RD should be considered one of the differential diagnoses in the setting of gastric wall thickening or subepithelial mass-like lesion. Deep biopsy with awareness of this entity might avoid unnecessary surgical intervention.

The changing faces of IgG4-related disease: Clinical manifestations and pathogenesis

Since the earliest reports in 2001, immunoglobulin G4 (IgG4)-related disease has been defined as an autoimmune systemic disease characterized by the lymphoplasmacytic infiltration of affected tissues leading to fibrosis and obliterative phlebitis along with elevated serum IgG4 levels. Prior to this unifying hypothesis, a plethora of clinical manifestations were considered as separate entities despite the similar laboratory profile. The pathology can be observed in virtually all organs and may thus be a challenging diagnosis, especially when the adequate clinical suspicion is not present or when obtaining a tissue biopsy is not feasible. Nonetheless, the most frequently involved organs are the pancreas and exocrine glands but these may be spared. Immunosuppressants lead to a prompt clinical response in virtually all cases and prevent histological sequelae and, as a consequence, an early differential diagnosis from other conditions, particularly infections and cancer, as well as an early treatment should be pursued. We describe herein two cases in which atypical disease manifestations were observed, i.e., one with recurrent neck lymph node enlargement and proptosis, and one with jaundice. Our understanding of the pathogenesis of IgG4-related disease is largely incomplete but data support a significant role for Th2 cytokines with the contribution of innate immunity factors such as Toll-like receptors, macrophages and basophils. Further, macrophages activated by IL4 overexpress B cell activating factors and contribute to chronic inflammation and the development of fibrosis. We cannot rule out the possibility that the largely variable disease phenotypes reflect different pathogenetic mechanisms and the tissue microenvironment may then contribute to the organ involvement.

Immunology of IgG4-related disease

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

Rare case of Helicobacter pylori-positive multiorgan IgG4-related disease and gastric cancer

A 61-year-old male from Northeast China presented with a 2-mo history of abdominal distension, pruritus and jaundice. Laboratory testing revealed an elevated serum IgG4 level. A computed tomography scan showed a typical feature of autoimmune pancreatitis (AIP) and cholecystocholangitis. Early gastric cancer was incidentally discovered when endoscopic untrasound-guided fine needle aspiration (EUS-FNA) of the pancreas was carried out. The patient underwent radical subtotal gastrectomy for gastric cancer combined with cholecystectomy. Helicobacter pylori (H. pylori) and IgG4-positive plasmacytes were detected in gastric cancer tissue, pancreatic EUS-FNA sample and resected gallbladder specimen by immunohistochemistry. The patient was diagnosed with H. pylori-positive IgG4-related AIP and sclerosing cholecystocholangitis as well as H. pylori-positive gastric cancer. He responded well to steroid therapy and remains healthy with no signs of recurrence at one year follow-up. We speculate that H. pylori might act as a trigger via direct or indirect action in the initiation of onset of gastric cancer and multiorgan IgG4-related disease.

Gastric calcifying fibrous tumor: A case of suspected immunoglobulin G4-related gastric disease

Gastrointestinal lesions resulting from immunoglobulin G4-related disease are classified into two types: One is a gastrointestinal lesion showing marked thickening of the wall, and the other is an IgG4-related pseudotumor. We report the case of a woman with gastric calcifying fibrous tumor undergoing endoscopic resection that contained 62 IgG4+ plasma cells per high-power field and an IgG4-to-IgG ratio of 41% in lesional plasma cells, which shared clinical and histopathological features associated with gastric IgG4-related pseudotumor. So, we postulate that calcifying fibrous tumor as part of the spectrum of IgG4-related disease might be the unifying concept with IgG4-related pseudotumor. Meanwhile, the patient had coexistent autoimmune diseases, including autoimmune atrophic gastritis, Hashimoto's thyroiditis, and possible primary biliary cirrhosis. The clinical follow-up evaluation was uneventful.

IgG4-related disease manifesting as an acute gastric-pericardial fistula

IgG4-related disease is a recently recognized entity linked initially to autoimmune pancreatitis and has been subsequently described in nearly every organ system. Men over the age of 50 represent the most affected demographic group and a comprehensive set of diagnostic criteria has been developed to aid treating clinicians. Though elevated levels of IgG4 in the serum are suggestive of the disease, definitive diagnosis is made on histopathology. Treatment is tailored to the clinical presentation with corticosteroid therapy known to have proven efficacy. Gastric manifestations of the IgG4-related disease primarily come in two varieties, notably chronic ulceration or pseudotumor formation. Autoimmune pancreatitis conveys increased risk for IgG4-related disease of the stomach, which is independent of Helicobacter pylori status. In this case report, we present an acute gastric-pericardial fistula secondary to IgG4-related disease that required urgent operative management. To our knowledge, this is the first report in the medical literature describing this complication of IgG4-related disease.

The clinical spectrum of IgG4-related disease

IgG4-related disease (IgG4-RD) is an emerging immune-mediated disease with the capability of involving essentially any organ. The epidemiology of this disease has not been explored in detail. A majority of patients reported in the literature to date are from Japan, but the condition has been described all across the world and there is no strong evidence to suggest a predilection for Asian populations. The mean age at diagnosis is approximately 60 years and there is a decided male predominance for many clinical features, with an overall male:female ratio of 8:3. A cardinal feature of IgG4-RD is single or multiple organ swelling that often raises concern for malignancy. IgG4-RD should be suspected in patients presenting with unexplained enlargement or swelling of one or more organs. Presenting features vary substantially according to the specialty to which patients present first; in addition, the disease can be diagnosed unexpectedly in pathological specimens or identified incidentally on radiology studies. Involvement of major organs is common and IgG4-RD may lead to organ failure, particularly in the pancreas, liver and biliary tree, kidneys, thyroid gland, lungs, and aorta. The diagnosis of IgG4-RD relies on the coexistence of various clinical, laboratory and histopathological findings, although none is pathognomonic by itself.