Autoimmune Pancreatitis Associated with Idiopathic Retroperitoneal Fibrosis

Association of autoimmune pancreatitis with Raghib syndrome

Key Clinical Message

Autoimmune pancreatitis (AIP) is a form of chronic pancreatitis scarcely found in children. Raghib syndrome is a rare congenital heart defect known as persistent left superior vena cava (LSVC) draining into the left atrium. Total signs of Raghib syndrome in AIP case accompanied by an IgG4-related disease were described.

Abstract

Autoimmune pancreatitis (AIP) is a form of chronic pancreatitis scarcely found in children. Raghib syndrome is a rare congenital heart defect known as persistent left superior vena cava (LSVC) draining into the left atrium. Here, we describe Raghib syndrome in AIP case accompanied by an IgG4-related disease (AIP/IgG4RD). A 13-year-old boy presented with a 3-month history of fever and abdominal pain. The laboratory findings showed SGOT and SGPT, ALP was increased, while amylase and γ-GT were normal. Immunoglobulins were normal, except for IgG. Endosonography, spiral CT of the abdomen, and cholangiopancreatography showed an enlargement of the pancreas. Contrast echocardiography discovered opacification of the coronary sinus and left atrium. Transesophageal echocardiography for LSVC revealed a dilatation in the coronary sinus, indicating persistent LSVC. Following the injection of agitated saline into the left antecubital vein, bubbles entered both left and right atria in LSVC. It is reasonable to exclude some of these rare disorders as Raghib syndrome, in cases that will be started on medications like corticosteroids, which increases the susceptibility to thromboembolic events.

IgG4-Related Disease Presenting as a Solitary Neck Mass

IgG4-related disease is a newly recognized entity associated with autoimmune conditions involving almost every organ system. It is characterized by elevated serum IgG4 as well as mass like tissue infiltration by IgG4-positive plasma cells. Imaging findings are nonspecific, vary depending on the site of disease, and include mass like enlargement of the salivary or lacrimal glands and enlarged lymph nodes. Radiographic findings often mimic malignancy, necessitating tissue sampling to confirm the diagnosis. Distinguishing IgG4-related disease from malignancy is important as IgG4 responds well to steroids and conservative management.

An immunoglobulin G4-related sclerosing disease of the small bowel: CT and small bowel series findings

Immunoglobulin G4 (IgG4)-related sclerosing disease is rare and is known to involve various organs. We present a case of histologically proven IgG4-related sclerosing disease of the small bowel with imaging findings on computed tomography (CT) and small bowel series. CT showed irregular wall thickening, loss of mural stratification and aneurysmal dilatation of the distal ileum. Small bowel series showed aneurysmal dilatations, interloop adhesion with traction and abrupt angulation.

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

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

Rethinking Ormond's disease: "idiopathic" retroperitoneal fibrosis in the era of IgG4-related disease

Idiopathic retroperitoneal fibrosis (RPF) is a periaortic sclerotic disease that encases adjacent retroperitoneal structures, particularly the ureters. A subset of idiopathic RPF cases can be associated with IgG4-related disease, but the frequency of this association is not clear. We selected 23 cases of idiopathic RPF and identified IgG4-related RPF cases based on the presence of IgG4+ plasma cells in the tissue, using an IgG4/IgG ratio cutoff of >40%. We then compared the IgG4-related RPF patients and the non-IgG4-related RPF patients in terms of both the presence of histopathologic features typical of IgG4-related disease and the simultaneous occurrence (or history) of other organ manifestations typical of IgG4-related disease. The IgG4-related RPF and non-IgG4-related RPF groups were also analyzed in terms of clinical, laboratory, and radiologic features and treatment review. We identified 13 cases of IgG4-related RPF (57% of the total cohort). The distinguishing features of IgG4-related RPF were histopathologic and extra-organ manifestations of IgG4-related disease. The IgG4-related RPF patients were statistically more likely than non-IgG4-related RPF patients to have retroperitoneal biopsies showing lymphoplasmacytic infiltrate (p = 0.006), storiform fibrosis (p = 0.006), or tissue eosinophilia (p = 0.0002). Demographics of the 2 groups, including a middle-aged, male predominance (mean age, 58 yr; 73% male), were similar. IgG4-related disease accounts for a substantial percentage of patients with "idiopathic" RPF. Histopathologic features such as storiform fibrosis, obliterative phlebitis, and tissue eosinophilia are critical to identifying this disease association. Extraretroperitoneal manifestations of IgG4-related disease are also often present among patients with IgG4-related RPF. Elevated IgG4/total IgG ratios in tissue biopsies are more useful than the number of IgG4+ plasma cells per high-power field in cases of RPF that are highly fibrotic.

Clinical features of 10 patients with IgG4-related retroperitoneal fibrosis

OBJECTIVE

To elucidate the clinical characteristics of IgG4-related retroperitoneal fibrosis (RF).

METHODS

IgG4-related RF was diagnosed when all of the following three criteria were fulfilled: retroperitoneal soft tissue masses surrounding the aorta and/or adjacent tissues, elevation of the serum IgG4 levels, and abundant infiltration of IgG4-positive plasma cells in at least one organ or site. Ten patients were diagnosed as having IgG4-related RF.

RESULTS

The mean age at diagnosis was 70.1 years, and the male-to-female ratio was 1:0.6. Only two patients had initial symptoms predominantly related to RF (back pain and edema of the lower extremities), while the remaining eight patients reported initial symptoms due to associated diseases. On laboratory examination, a severe inflammatory reaction was observed in one patient. Elevation of the levels of serum IgG and IgE, eosinophilia and positivity of antinuclear antibodies were detected in seven, five, two and seven patients, respectively. The retroperitoneal masses were detected primarily in the left renal hilus in four patients, in the periaortic region in five patients and in both regions in one patient. Hydronephrosis was present in five patients. The histological diagnosis was confirmed in the retroperitoneal masses (resection, n=1 biopsy, n=2) and extraretroperitoneal lesions (n=7). Twenty-four other IgG4-related diseases were found to be associated with IgG4-related RF in nine patients (autoimmune pancreatitis (n=2), sialadenitis (n=4), dacryoadenitis (n=5), lymphadenopathy (n=9), pulmonary pseudotumor (n=1) and pituitary pseudotumor (n=1)). Seven patients underwent steroid therapy, all of whom responded well and showed no instances relapse.

CONCLUSION

IgG4-related RF has several clinical characteristic features. Our diagnostic criteria may be helpful in obtaining a correct diagnosis.

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

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

Plasma cell type of Castleman's disease involving renal parenchyma and sinus with cardiac tamponade: case report and literature review

Castleman's disease is an uncommon disorder characterized by benign proliferation of the lymphoid tissue that occurs most commonly in the mediastinum. Although unusual locations and manifestations have been reported, involvement of the renal parenchyma and sinus, and moreover, manifestations as cardiac tamponade are extremely rare. Here, we present a rare case of Castleman's disease in the renal parenchyma and sinus that also accompanied cardiac tamponade.

Diagnosis and management of autoimmune pancreatitis

• AIP is a heterogeneous disease with two distinct subtypes, now called type 1 and type 2. The proportions of these subtypes vary in their distribution worldwide. • Pancreatic cancer is the leading differential diagnosis for AIP, although AIP can mimic any other major pancreatobiliary disease. • Cross-sectional abdominal imaging CT/MRI should form the cornerstone to the diagnosis of AIP. • Serum IgG4 provides collateral evidence for the diagnosis of AIP and should not be the sole basis for the diagnosis. False-positive elevation in serum IgG4 can be seen in up to 10% of patients with pancreatic cancer. • A steroid trial should be performed only in select situations after ruling out pancreatic cancer and by gastroenterologists experienced in treating AIP. • Disease recurrence can be seen in up to 40% of patients after initial steroid therapy.

The Clinical and Pathological Features of IgG(4)-Related Disease

The rapidly emerging disorder now known as IgG(4)-related disease (IgG(4)-RD) includes a variety of clinical entities once regarded as being entirely separate diseases. Manifestations of IgG(4)-RD have now been reported in essentially all organ systems. Regardless of which organ is involved, tissue biopsies reveal striking histopathological similarities. The hallmark pathology findings are diffuse lymphoplasmacytic infiltrates, abundant IgG(4)-positive plasma cells, modest tissue eosinophilia, and extensive fibrosis. Tumorous swelling and obliterative phlebitis are other frequently observed features. Polyclonal elevations of serum IgG(4) are found in approximately 70% of patients. Many questions pertaining to the etiology, pathophysiology, epidemiology, clinical features, therapy, disease monitoring, and long-term outcomes remain to be addressed. This paper focuses on the clinical and pathological features of IgG(4)-RD.

IgG4-related sclerosing disease: autoimmune pancreatitis and extrapancreatic manifestations

Autoimmune pancreatitis is the pancreatic manifestation of IgG4-related sclerosing disease, which recently was recognized as a distinct disease entity. Numerous extrapancreatic organs, such as the bile ducts, gallbladder, kidneys, retroperitoneum, thyroid, salivary glands, lung, mediastinum, lymph nodes, and prostate may be involved, either synchronously or metachronously. Most cases of autoimmune pancreatitis are associated with elevated serum IgG4 levels; extensive IgG4-positive plasma cells; and infiltration of lymphocytes into various organs, which leads to fibrosis. There are several established diagnostic criteria systems that are used to diagnose autoimmune pancreatitis and that rely on a combination of imaging findings of the pancreas and other organs, serologic findings, pancreatic histologic findings, and response to corticosteroid therapy. It is important to recognize multiorgan involvement of IgG4-related sclerosing disease and be familiar with its clinical and imaging features because it demonstrates a favorable response to treatment.

Autoimmune pancreatitis

The purpose of this review is to provide a concise view of the existing knowledge of autoimmune pancreatitis (AIP) for practicing clinicians. AIP is a rare disease whose recognition and understanding are evolving. It is a type of chronic pancreatitis that often presents as obstructive jaundice, has a distinctive histology, and is exquisitely sensitive to steroid therapy. This form of chronic pancreatitis has a unique clinical, biochemical, and radiological profile. The term "AIP" encompasses two subtypes: types 1 and 2. Type 1 AIP is the pancreatic manifestation of a systemic fibro-inflammatory disease called immunoglobulin G4-associated systemic diseases. Type 2 AIP has been shown to be associated with inflammatory bowel disease. Existing criteria are geared towards the diagnosis of type 1 AIP. At present, pancreatic histology is a requirement for the definitive diagnosis of type 2 AIP. AIP can mimic most other pancreatic diseases in its presentation, but in clinical practice, it often has to be differentiated from pancreatic cancer. There are established criteria and algorithms not only to diagnose AIP, but also to differentiate it from pancreatic cancer. The utility of these algorithms and the approach to management are discussed here.

IgG4-associated cholecystitis: another clue in the diagnosis of autoimmune pancreatitis

PURPOSE

Autoimmune pancreatitis (AIP) is the pancreatic manifestation of IgG4-associated systemic disease (ISD). Criteria for diagnosis of AIP include recognition of extra-pancreatic organ involvement. Because the diagnosis of AIP can be challenging, even for experts, it is important for clinicians to recognize other target organ damage in this disease. Typical gallbladder findings in AIP have been increasingly recognized. Because cholecystectomy is common in the community, the availability of previous tissue from the gallbladder can provide an important supportive clue in the diagnosis of AIP. The objective of this review is to examine the literature on common gallbladder pathology findings in AIP, and discuss their clinical utility.

RESULTS

Gallbladder involvement in AIP seems to be common. Transmural lymphoplasmacytic inflammatory infiltrates, extramural inflammatory nodules, the presence of tissue eosinophilia, phlebitis, and increased tissue IgG4 are all seen more frequently in the gallbladders of patients with AIP. These findings are not 100% specific, because some can be seen in primary sclerosing cholangitis and pancreatic adenocarcinoma.

CONCLUSION

Cholecystectomy for the purpose of diagnosing AIP is not recommended. However, if gallbladder specimens from a previous cholecystectomy are available, an expert review of gallbladder slides with IgG4 immunostaining may help to provide additional criteria for diagnosis of autoimmune pancreatitis.

A clinical overview of IgG4-related systemic disease

PURPOSE OF REVIEW

To summarize the existing knowledge of various clinical presentations of IgG4-related systemic disease (IgG4-RSD) and to review the evolving list of organs affected by IgG4-RSD.

RECENT FINDINGS

The term IgG4-RSD encompasses a variety of clinical entities once regarded as being entirely separate diseases. The list of organs associated with this condition is growing steadily. Tissue biopsies reveal striking histopathological similarity, regardless of which organ is involved, although subtle differences across organs exist. Diffuse lymphoplasmacytic infiltrates, presence of abundant IgG4-positive plasma cells and extensive fibrosis are the hallmark pathology findings. Tumorous swelling, eosinophilia, and obliterative phlebitis are other frequently observed features. Polyclonal elevations of serum IgG4 are found in most but not all patients.

SUMMARY

IgG4-RSD is an underrecognized condition about which knowledge is now growing rapidly. Yet there remain many unknowns with regard to its cause, pathogenesis, various clinical presentations, approach to treatment, disease monitoring, and long-term outcomes. A wide variety of organs can be involved in IgG4-RSD. Clinicians should be aware of this entity and consider the diagnosis in the appropriate settings.

IgG4-related sclerosing disease: a critical appraisal of an evolving clinicopathologic entity

An elevated serum titer of immunoglobulin G4 (IgG4), the least common (3% to 6%) of the 4 subclasses of IgG, is a surrogate marker for the recently characterized IgG4-related sclerosing disease. The syndrome affects predominantly middle-aged and elderly patients, with male predominance. The patients present with symptoms referable to the involvement of 1 or more sites, usually in the form of mass lesions. The prototype is IgG4-related sclerosing pancreatitis (also known as autoimmune pancreatitis), most commonly presenting as painless obstructive jaundice with or without a pancreatic mass. Other common sites of involvement are the hepatobiliary tract, salivary gland, orbit, and lymph node, but practically any organ-site can be affected, such as retroperitoneum, aorta, mediastinum, soft tissue, skin, central nervous system, breast, kidney, prostate, upper aerodigestive tract, and lung. The patients usually have a good general condition, with no fever or constitutional symptoms. Common laboratory findings include raised serum globulin, IgG, IgG4, and IgE, whereas lactate dehydrogenase is usually not raised. Some patients have low titers of autoantibodies (such as antinuclear antibodies and rheumatoid factor). The disease often shows excellent response to steroid therapy. The natural history is characterized by the development of multiple sites of involvement with time, sometimes after many years. However, the disease can remain localized to 1 site in occasional patients. The main pathologic findings in various extranodal sites include lymphoplasmacytic infiltration, lymphoid follicle formation, sclerosis and obliterative phlebitis, accompanied by atrophy and loss of the specialized structures of the involved tissue (such as secretory acini in pancreas, salivary gland, or lacrimal gland). The relative predominance of the lymphoplasmacytic and sclerotic components results in 3 histologic patterns: pseudolymphomatous, mixed, and sclerosing. Immunostaining shows increased IgG4+ cells in the involved tissues (>50 per high-power field, with IgG4/IgG ratio >40%). The lymph nodes show multicentric Castleman disease-like features, reactive follicular hyperplasia, interfollicular expansion, or progressive transformation of germinal centers, with the unifying feature being an increase in IgG4+ plasma cells on immunostaining. The nature and pathogenesis of IgG4-related sclerosing disease are still elusive. Occasionally, the disease can be complicated by the development of malignant lymphoma and possibly carcinoma.

The birthday of a new syndrome: IgG4-related diseases constitute a clinical entity

IgG4-related disease is a distinct clinical entity, whose characteristic features are the following; Serum IgG4 is prominently elevated, IgG4-positive plasma cells infiltrate in involved tissues, various mass-forming lesions with fibrosis develop in a timely and spatial manner and the response to corticosteroids is prompt and good. IgG4-related diseases mainly target two organs. One is the pancreas (autoimmune pancreatitis; AIP), and the other comprises the lacrimal and salivary glands, the clinical phenotype is Mikulicz's disease (MD). MD has long been considered a manifestation of Sjögren's syndrome (SS). However, we noticed several clinical differences in case of MD from SS; no deflection of female sex differences, mild sicca syndrome, good response to corticosteroids, no positivity of anti-SS-A/SS-B antibodies. In addition, elevated level of serum IgG4 and abundant infiltration of plasma cells expressing IgG4 were reported in MD patients. Those are common features of IgG4-related diseases. MD often coexisted with IgG4-related diseases such as AIP, retroperitoneal fibrosis, and IgG4-associated nephropathy. Based on those findings, it has been considered to recognize IgG4-related diseases including MD as a new clinical entity. The etiology of IgG4-related systemic diseases remains to be elucidated. It is necessary to accumulate and analyze larger data from patients worldwide.

Autoimmune pancreatitis: differentiation from pancreatic carcinoma and normal pancreas on the basis of enhancement characteristics at dual-phase CT

OBJECTIVE

The purposes of this study were to define the pancreatic enhancement of autoimmune pancreatitis at dual-phase CT and to compare it with that of pancreatic carcinoma and a normal pancreas.

MATERIALS AND METHODS

Dual-phase CT scans of 101 patients (43 with autoimmune pancreatitis, 13 cases of which were focal; 33 with pancreatic carcinoma, and 25 with a normal pancreas) were evaluated. One radiologist measured the CT attenuation of the pancreatic parenchyma and pancreatic masses in both the pancreatic and hepatic phases of imaging. The mean CT attenuation value of the pancreatic parenchyma in patients with autoimmune pancreatitis was compared with that in patients with a normal pancreas. The mean CT attenuation value of the focal masses in the focal form of autoimmune pancreatitis was compared with that of carcinomas.

RESULTS

In the pancreatic phase, the mean CT attenuation value of the pancreatic parenchyma in patients with autoimmune pancreatitis was significantly lower than that in patients with a normal pancreas (autoimmune pancreatitis, 85 HU; normal pancreas, 104 HU; p < 0.05). In the hepatic phase, however, the mean CT attenuation values were not significantly different (autoimmune pancreatitis, 96 HU; normal pancreas, 89 HU; p = 0.6). In the pancreatic phase, the mean CT attenuation value of the mass in autoimmune pancreatitis was not significantly different from that of carcinoma (autoimmune pancreatitis, 71 HU; carcinoma, 59 HU; p = 0.06), but in the hepatic phase, the value was significantly higher than that of carcinoma (autoimmune pancreatitis, 90 HU; carcinoma, 64 HU; p < 0.001).

CONCLUSION

At dual-phase CT, the enhancement patterns of the pancreas and pancreatic masses in patients with autoimmune pancreatitis are different from those of pancreatic carcinoma and normal pancreas.

Characteristic findings in images of extra-pancreatic lesions associated with autoimmune pancreatitis

PURPOSE

Autoimmune pancreatitis is a unique form of chronic pancreatitis characterized by a variety of extra-pancreatic involvements which are frequently misdiagnosed as lesions of corresponding organs. The purpose of this study was to clarify the diagnostic imaging features of extra-pancreatic lesions associated with autoimmune pancreatitis.

MATERIALS AND METHODS

We retrospectively analyzed diagnostic images of 90 patients with autoimmune pancreatitis who underwent computer-assisted tomography, magnetic resonance imaging, and/or gallium-67 scintigraphy before steroid therapy was initiated.

RESULTS

AIP was frequently (92.2%) accompanied by a variety of extra-pancreatic lesions, including swelling of lachrymal and salivary gland lesions (47.5%), lung hilar lymphadenopathy (78.3%), a variety of lung lesions (51.2%), wall thickening of bile ducts (77.8%), peri-pancreatic or para-aortic lymphadenopathy (56.0%), retroperitoneal fibrosis (19.8%), a variety of renal lesions (14.4%), and mass lesions of the ligamentum teres (2.2%). Characteristic findings in CT and MRI included lymphadenopathies of the hilar, peri-pancreatic, and para-aortic regions; wall thickening of the bile duct; and soft tissue masses in the kidney, ureters, aorta, paravertebral region, ligamentum teres, and orbit.

CONCLUSIONS

Recognition of the diagnostic features in the images of various involved organs will assist in the diagnosis of autoimmune pancreatitis and in differential diagnoses between autoimmune pancreatitis-associated extra-pancreatic lesions and lesions due to other pathologies.

Possible association between IgG4-associated systemic disease with or without autoimmune pancreatitis and non-Hodgkin lymphoma

OBJECTIVES

IgG4-associated systemic disease (ISD) is a multiorgan fibroinflammatory disorder whose pancreatic manifestation is called autoimmune pancreatitis (AIP). We describe 3 patients who developed non-Hodgkin lymphoma during the follow-up of ISD.

METHODS

At our institution's pancreas clinic, we have prospectively and retrospectively examined patients with ISD with (n = 101) or without (n = 10) AIP (mean age, 59 years; 90 males and 21 females). We reviewed the medical records of all 111 patients to identify patients who developed non-Hodgkin lymphoma during the follow-up since their first presentation of ISD. Standardized incidence rate was calculated.

RESULTS

The 111 patients with ISD with or without AIP had 331 patient-years of observation during which 3 patients had a diagnosis of non-Hodgkin lymphoma 3 to 5 years after the diagnosis of ISD. In these patients who later developed lymphoma, ISD involved the pancreas (AIP) in 2 and salivary gland in 1. Non-Hodgkin lymphoma had extranodal involvement in all patients (liver [n = 2], adrenal glands [n=1], kidney [n= 1], and lung [n = 1]). Standardized incidence rate was 16.0 (95% confidence interval, 3.3-45.5).

CONCLUSIONS

We report 3 cases of non-Hodgkin lymphoma that developed during the follow-up of ISD suggesting that patients with ISD may be at an increased risk of developing non-Hodgkin lymphoma.

Abdominal extrapancreatic lesions associated with autoimmune pancreatitis: Radiological findings and changes after therapy

PURPOSE

To evaluate imaging findings of abdominal extrapancreatic lesions associated with autoimmune pancreatitis (AIP) and changes after steroid therapy.

METHODS AND MATERIALS

This study included nine AIP patients with abdominal extrapancreatic lesions, which were determined by retrospective radiological review. CT (initial and follow-up, n=9) and MR imaging (initial, n=5) were reviewed by two radiologists in consensus to determine imaging characteristics (i.e., size, number, attenuation or signal intensity, and contrast enhancement of the lesions, and the presence of overlying capsule retraction) and evaluate changes with steroid therapy of abdominal extrapancreatic lesions associated with AIP.

RESULTS

The most common abdominal extrapancreatic lesion associated with AIP was retroperitoneal fibrosis (RPF) in six patients. In five patients, CT and MR imaging revealed single or multiple, round- or wedge-shaped, hypoattenuating or hypointense, enhancing lesions in the renal cortex or pelvis. Other lesions included a geographic, ill-defined, hypoattenuating lesion with or without overlying capsule retraction in the liver in two and bile duct dilatation with or without bile duct wall thickening in four. Over a follow-up period of 6-81 months, CT exams of eight patients demonstrated partial or complete improvement of the abdominal extrapancreatic lesions, albeit their improvement in general lagged behind that of the pancreatic lesion.

CONCLUSION

On CT or MR imaging, the abdominal extrapancreatic lesions associated with AIP are various in the retroperitoneum, liver, kidneys and bile ducts, and are reversible with steroid therapy.

IgG4-related inflammatory abdominal aortic aneurysm associated with autoimmune pancreatitis

An association between autoimmune pancreatitis (AIP) and inflammatory abdominal aortic aneurysm (AAA) has never been reported. Reported herein is a case of IgG4-related inflammatory AAA accompanying metachronous AIP. A 77-year-old man presented with malaise and intermittent lower abdominal pain. Radiological examination showed inflammatory AAA and right hydronephrosis caused by retroperitoneal fibrosis. Surgical correction of the AAA was performed, but high levels of systemic inflammatory markers persisted. Four months after surgery, the patient presented with epigastric pain, backache, and jaundice. His serum IgG4 concentration was high (571 mg/mL), and he was diagnosed with AIP, based on clinical and radiological findings. Corticosteroid therapy resulted in improvement of the clinical findings and lowered his serum IgG4 levels. Subsequent histological examination of a specimen from the aortic wall showed irregular proliferation of fibroblastic and myofibroblastic cells, severe lymphoplasmacytic infiltration, and obliterative phlebitis in the adventitia. Furthermore, on immunohistochemistry many plasma cells within the lesion were found to be positive for IgG4. These findings suggest that inflammatory AAA has a pathological process similar to that of AIP, and that some cases of inflammatory AAA and retroperitoneal fibrosis may be aortic and periaortic lesions of an IgG4-related sclerosing disease.

Lymphoplasmacytic sclerosing pancreatitis and retroperitoneal fibrosis

Although cases of lymphoplasmacytic sclerosing pancreatitis (LSP) associated with idiopathic retroperitoneal fibrosis have been reported, the association is rare. We describe a 74-year-old man who presented with obstructive jaundice and weight loss. Nineteen months earlier, he had been diagnosed with idiopathic retroperitoneal fibrosis and treated with bilateral ureteric stents. Initial investigations were suggestive of a diagnosis of LSP, however, a malignant cause could not be ruled out. He underwent an exploratory laparotomy and frozen sections confirmed the diagnosis of LSP. An internal biliary bypass was performed using a Roux loop of jejunum, and the patient made an uneventful recovery. This case illustrates the difficulty in distinguishing LSP from pancreatic carcinoma preoperatively.

18F-Fluorodeoxyglucose Positron Emission Tomography Features of Idiopathic Retroperitoneal Fibrosis

OBJECTIVE

To evaluate the 18F-fluorodeoxyglucose (FDG) uptake features of idiopathic retroperitoneal fibrosis (IRF).

METHODS

18F-Fluorodeoxyglucose positron emission tomographic (PET) or PET/computed tomographic findings were retrospectively reviewed in 6 patients with IRF. FDG PET or PET/computed tomography was performed 1 and 2 hours after FDG injection. The FDG level was scored using a 4-point scale, and the intensity of FDG uptake was quantified using the maximum standardized uptake value (SUVmax).

RESULTS

In the 1-hours images, intense FDG uptake by IRF was observed in 5 patients before steroid treatment, but no abnormal uptake was noted in 1 patient receiving steroid treatment. The SUVmax in IRF increased from a mean +/- SD of 6.0 +/- 1.2 (range, 4.9-7.6) to 7.6 +/- 1.1 (range, 5.9-8.2) for all 4 patients who underwent 1 and 2 hours dual-time point imaging. Abnormal uptake was also noted in the mediastinum and the pancreas in 1 and 2 patients, and the diagnoses of mediastinal fibrosis and autoimmune pancreatitis were made, respectively. The SUVmax was stable or increased in the 3 lesions of mediastinal fibrosis and autoimmune pancreatitis.

CONCLUSION

FDG PET may be a reliable means of evaluating disease activity and the extent of IRF, but dual-time point imaging may not be useful to differentiate malignancy from IRF.

Renal involvement in patients with autoimmune pancreatitis: CT and MR imaging findings

PURPOSE

To retrospectively evaluate computed tomographic (CT) and magnetic resonance (MR) imaging renal findings at clinical presentation, during treatment, and at follow-up in patients with autoimmune pancreatitis (AIP).

MATERIALS AND METHODS

This HIPAA-compliant study received institutional review board approval. All patients included had previously consented to the use of their medical records for the purpose of research. Forty-five patients (38 male and seven female patients; mean age, 64 years) with diagnosis of AIP were included. Forty patients underwent CT or MR imaging at clinical presentation; 33 patients (including five without imaging at presentation) underwent follow-up. CT and MR images were reviewed in consensus by two radiologists for the presence of renal involvement. Various features were evaluated. Clinical characteristics at presentation were compared between patients with and patients without renal involvement.

RESULTS

Of the 40 patients who underwent imaging at presentation, 14 (35%) had renal involvement (12 with parenchymal involvement and five with extraparenchymal involvement). Renal parenchymal lesions showed decreased enhancement and appeared as small peripheral cortical nodules, round or wedge-shaped lesions, or diffuse patchy involvement. Thirteen patients with renal involvement at presentation underwent a follow-up study. Renal lesions in 10 patients regressed (in nine, after steroid treatment) but progressed in three patients without steroid treatment. Renal lesions were found in two other patients during follow-up. No significant difference in the clinical characteristics was found between patients with and patients without renal involvement.

CONCLUSION

Renal involvement in patients with AIP is relatively common and predominantly involves the cortex of the kidney. The lesions improve after steroid treatment but can progress without steroid treatment.

IgG4-positive plasma cell infiltration in the diagnosis of autoimmune pancreatitis

Autoimmune pancreatitis typically produces an enlarged pancreas with narrowing of the pancreatic duct, and can mimic carcinoma. Autoimmune pancreatitis usually responds to corticosteroid treatment, making it important to differentiate from pancreatic ductal adenocarcinoma. Affected patients often have an elevated serum IgG4. It has been proposed that increased numbers of IgG4-positive plasma cells in tissue might be a marker for the condition. We investigated the role of IgG4 staining in the diagnosis of autoimmune pancreatitis, first in resected pancreas specimens (29 autoimmune pancreatitis, nine chronic alcoholic pancreatitis and 25 pancreatic cancer), then in pancreatic needle biopsies. Immunohistochemical stains for IgG4 were scored as none, mild, moderate or marked, according to published criteria. Moderate to marked numbers of IgG4-positive plasma cells were seen in 21/29 autoimmune pancreatitis patients, and were distributed in and around ducts, in interlobular fibrous tissue and in peripancreatic fat. In contrast, eight of nine examples of chronic alcoholic pancreatitis and 22/25 ductal adenocarcinomas had scores of none or mild. When we subdivided autoimmune pancreatitis into the histologic subtypes lymphoplasmacytic sclerosing pancreatitis and idiopathic duct-destructive pancreatitis, 16/17 lymphoplasmacytic sclerosing pancreatitis had moderate to marked staining, compared to five to 12 idiopathic duct-destructive pancreatitis. Needle biopsies from nine patients suspected of having autoimmune pancreatitis had increased numbers of IgG4 cells. We conclude that pancreatic tissue from patients with autoimmune pancreatitis often shows moderate or marked infiltration by IgG4-positive plasma cells (>10/HPF). This is particularly so in the subtype we have designated lymphoplasmacytic sclerosing pancreatitis. We rarely see IgG4 staining in patients with chronic alcoholic pancreatitis and pancreatic ductal adenocarcinoma. IgG4-positive plasma cells are a useful marker for the tissue diagnosis of autoimmune pancreatitis.

Autoimmune pancreatitis with retroperitoneal fibrosis which responded to steroid therapy but was complicated with refractory renal dysfunction

A 58-year-old male had been diagnosed as having autoimmune pancreatitis (AIP) from the results of serological examinations and image findings. He was treated with prednisolone (PSL) for 3.5 months. Fifteen months later, follow-up CT revealed the main pancreatic duct (MPD) dilatation in the pancreas body to tail and right hydronephrosis caused by complicated retroperitoneal mass. We diagnosed him as having recurrent AIP with retroperitoneal fibrosis, and restarted PSL treatment. After one month, Examinations indicated amelioration of the MPD dilatation and right hydronephrosis, but not the right renal failure. This case indicates the importance of maintenance of PSL treatment.

Prevalence and distribution of extrapancreatic lesions complicating autoimmune pancreatitis

BACKGROUND

Autoimmune pancreatitis is a unique form of chronic pancreatitis characterized by high serum IgG4 concentrations and abundant IgG4-bearing plasma cell infiltration in the pancreatic lesion, and it has been reported to be associated with a variety of extrapancreatic lesions, leading us to postulate the concept of a systemic inflammatory disease. To confirm this, we clarified the exact distribution of these extrapancreatic lesions and provide a panoramic view of them.

METHODS

The frequency, distribution, clinical characteristics, and pathology of five extrapancreatic lesions were determined in 64 patients with autoimmune pancreatitis by examining clinical and laboratory findings.

RESULTS

The most frequent extrapancreatic lesion was hilar lymphadenopathy (80.4%), followed by extrapancreatic bile duct lesions (73.9%), lachrymal and salivary gland lesions (39.1%), hypothyroidism (22.2%), and retroperitoneal fibrosis (12.5%). No patients had all five types of lesions. Patients with hilar lymphadenopathy or lachrymal and salivary gland lesions were found to have significantly higher IgG4 levels than those without (P = 0.0042 and 0.0227, respectively). Patients with three lesions were found to have significantly higher IgG4 levels than those with no lesion, suggesting that patients with multiple extrapancreatic lesions have active disease. Similar to pancreatic lesions, extrapancreatic lesions have a characteristic histological finding of abundant IgG4-bearing plasma cell infiltration, and they respond favorably to corticosteroid therapy.

CONCLUSIONS

Autoimmune pancreatitis was recognized as a systemic inflammatory disease. Furthermore, recognition of these characteristic findings will aid in the correct diagnosis of this disease.

Hyper-IgG4 disease: report and characterisation of a new disease

BACKGROUND

We highlight a chronic inflammatory disease we call 'hyper-IgG4 disease', which has many synonyms depending on the organ involved, the country of origin and the year of the report. It is characterized histologically by a lymphoplasmacytic inflammation with IgG4-positive cells and exuberant fibrosis, which leaves dense fibrosis on resolution. A typical example is idiopathic retroperitoneal fibrosis, but the initial report in 2001 was of sclerosing pancreatitis.

METHODS

We report an index case with fever and severe systemic disease. We have also reviewed the histology of 11 further patients with idiopathic retroperitoneal fibrosis for evidence of IgG4-expressing plasma cells, and examined a wide range of other inflammatory conditions and fibrotic diseases as organ-specific controls. We have reviewed the published literature for disease associations with idiopathic, systemic fibrosing conditions and the synonyms: pseudotumour, myofibroblastic tumour, plasma cell granuloma, systemic fibrosis, xanthofibrogranulomatosis, and multifocal fibrosclerosis.

RESULTS

Histology from all 12 patients showed, to varying degrees, fibrosis, intense inflammatory cell infiltration with lymphocytes, plasma cells, scattered neutrophils, and sometimes eosinophilic aggregates, with venulitis and obliterative arteritis. The majority of lymphocytes were T cells that expressed CD8 and CD4, with scattered B-cell-rich small lymphoid follicles. In all cases, there was a significant increase in IgG4-positive plasma cells compared with controls. In two cases, biopsies before and after steroid treatment were available, and only scattered plasma cells were seen after treatment, none of them expressing IgG4. Review of the literature shows that although pathology commonly appears confined to one organ, patients can have systemic symptoms and fever. In the active period, there is an acute phase response with a high serum concentration of IgG, and during this phase, there is a rapid clinical response to glucocorticoid steroid treatment.

CONCLUSION

We believe that hyper-IgG4 disease is an important condition to recognise, as the diagnosis can be readily verified and the outcome with treatment is very good.

Autoimmune pancreatitis associated with idiopathic retroperitoneal fibrosis: a case report

A 69-year-old man presented with obstructive jaundice and dark urine. Contrast-enhanced computed tomography revealed an enlarged pancreas with homogenous enhancement. Endoscopic retrograde pancreatography demonstrated short-segmental, irregular narrowing of the main pancreatic duct. The patient underwent exploratory laparotomy and needle biopsies of the pancreas, which showed marked fibrotic change with lymphocyte infiltration. These clinicopathologic findings suggested autoimmune pancreatitis. Four years later, computed tomography demonstrated marked periaortic soft tissue surrounding a calcified infrarenal abdominal aorta compatible with retroperitoneal fibrosis. We diagnosed retroperitoneal fibrosis with noncontiguous pancreatic fibrosis. This patient responded well to corticosteroid treatment. Autoimmune pancreatitis associated with idiopathic retroperitoneal fibrosis seems to be extremely rare, and to our knowledge, only a few cases have been reported.

Autoimmune pancreatitis: proposal of IgG4-related sclerosing disease

Autoimmune pancreatitis (AIP) is a peculiar type of pancreatitis of presumed autoimmune etiology. Many new clinical aspects of AIP have been clarified during the past 10 years, and AIP has become a distinct entity recognized worldwide. However, its precise pathogenesis or pathophysiology remains unclear. As AIP dramatically responds to steroid therapy, accurate diagnosis of AIP is necessary to avoid unnecessary surgery. Characteristic dense lymphoplasmacytic infiltration and fibrosis in the pancreas may prove to be the gold standard for diagnosis of AIP. However, since it is difficult to obtain sufficient pancreatic tissue, AIP should be diagnosed currently based on the characteristic radiological findings (irregular narrowing of the main pancreatic duct and enlargement of the pancreas) in combination with serological findings (elevation of serum gamma-globulin, IgG, or IgG4, along with the presence of autoantibodies), clinical findings (elderly male preponderance, fluctuating obstructive jaundice without pain, occasional extrapancreatic lesions, and favorable response to steroid therapy), and histopathological findings (dense infiltration of IgG4-positive plasma cells and T lymphocytes with fibrosis and obliterative phlebitis in various organs). It is apparent that elevation of serum IgG4 levels and infiltration of abundant IgG4-positive plasma cells into various organs are rather specific to AIP patients. We propose a new clinicopathological entity, "IgG4-related sclerosing disease", and suggest that AIP is a pancreatic lesion reflecting this systemic disease.

Autoimmune pancreatitis metachronously associated with retroperitoneal fibrosis with IgG4-positive plasma cell infiltration

Retroperitoneal fibrosis is an uncommon disorder characterized by the formation of a dense plaque of fibrous tissue in the retroperitoneum, and its etiology remains unknown. Autoimmune pancreatitis is a rare type of chronic pancreatitis characterized by fibrosis with abundant infiltration of IgG4-positive plasma cells and lymphocytes and obliterative phlebitis in the pancreas. We present a case of autoimmune pancreatitis that developed 10 mo after the occurrence of retroperitoneal fibrosis. Histological findings of the resected retroperitoneal mass were marked periureteral fibrosis with abundant infiltration of IgG4-positive plasma cells and lymphocytes and obliterative phlebitis. These findings suggest a common pathophysiological mechanism for retroperitoneal fibrosis and autoimmune pancreatitis in this case. Some cases of retroperitoneal fibrosis might be a retroperitoneal lesion of IgG4-related sclerosing disease.

Autoimmune pancreatitis: radiologic findings in 20 patients

BACKGROUND

Autoimmune pancreatitis is a new clinical entity that is characterized by peculiar histopathologic and laboratory findings and by a dramatic clinical response to corticosteroid therapy. We evaluated the radiologic findings of autoimmune pancreatitis.

METHODS

Computed tomographic, magnetic resonance imaging, endoscopic retrograde cholangiopancreatographic, and ultrasonographic findings of 20 patients with autoimmune pancreatitis in our hospital between November 2000 and December 2003 were retrospectively reviewed regarding changes and ancillary findings in the pancreatic parenchyma, the main pancreatic duct, peripancreatic vessels, and distal common bile duct. In addition, follow-up images were reviewed for changes in any abnormality seen on the initial examinations.

RESULTS

Pancreatic parenchymal enlargement was invariably seen that was diffuse (n = 19) or focal (n = 1), with homogeneous contrast enhancement on computed tomography (n = 20) and magnetic resonance imaging (n = 15). Capsule-like rim enhancement was seen in six patients. There was focal (n = 18) or diffuse (n = 2) narrowing of the main pancreatic duct and it was usually multifocal (n = 17) in the former. Narrowing of the peripancreatic veins was seen in 14 patients. There was tapered (n = 15) or abrupt (n = 3) narrowing of the distal common bile duct in 18 patients, with contrast enhancement of the narrowed segment in eight. Invariably, changes in the pancreatic parenchyma, main pancreatic duct, peripancreatic vessels, and common bile duct were normalized on follow-up studies after steroid therapy.

CONCLUSION

In this series, common radiologic findings of autoimmune pancreatitis were (a) diffuse pancreas enlargement, (b) multifocal narrowing of the main pancreatic duct, (c) narrowing of peripancreatic veins, and (d) tapered narrowing of the distal common bile duct with frequent contrast enhancement. These findings were usually reversible with steroid therapy.

IgG4-related sclerosing disease incorporating sclerosing pancreatitis, cholangitis, sialadenitis and retroperitoneal fibrosis with lymphadenopathy

BACKGROUND AND AIMS

Autoimmune pancreatitis is usually associated with elevated serum IgG4 concentrations, and sometimes with sclerosing cholangitis and Sjögren's syndrome. This study aimed to elucidate the proposed entity of IgG4-related sclerosing disease.

METHODS

Subjects were patients with autoimmune pancreatitis (n = 26), sclerosing sialadenitis (n = 5), chronic alcoholic pancreatitis (n = 20), sialolithiasis (n = 34), Sjögren's syndrome (n = 50), and primary sclerosing cholangitis (n = 3). Sections of various organs and tissues of these patients were examined immunohistochemically using antibodies to CD4-T, CD8-T, and CD20-B cell subsets and IgG4, and serum IgG4 concentrations were measured.

RESULTS

Patients with autoimmune pancreatitis were associated with sclerosing cholangitis (n = 23), sclerosing sialadenitis (n = 2), retroperitoneal fibrosis (n = 2), and abdominal (n = 5) and cervical (n = 4) lymphadenopathy. They demonstrated infiltrations of more abundant IgG4-positive plasma cells in the pancreas, peripancreatic retroperitoneal tissues, extrahepatic bile duct, gallbladder, stomach, minor salivary gland, and abdominal lymph nodes compared with those of other diseases (p < 0.01). Such infiltrations were also observed in the minor salivary gland and submandibular gland of patients with sclerosing sialadenitis (p < 0.01). Serum IgG4 concentrations were significantly elevated in patients with autoimmune pancreatitis and sclerosing sialadenitis (p < 0.01).

CONCLUSION

We propose a new clinicopathological entity of IgG4-related sclerosing disease incorporating sclerosing pancreatitis, cholangitis, sialadenitis and retroperitoneal fibrosis with lymphadenopathy.

Autoimmune pancreatitis with hepatic inflammatory pseudotumor

We report a case of autoimmune pancreatitis (AIP) with hepatic inflammatory pseudotumor (IP). The patient was clinically diagnosed as having multiple metastatic tumors originated from cholangiocellular carcinoma as well as autoimmune pancreatitis and underwent left lobectomy of the liver. Histological examination showed a diffuse or dense lymphoplasmacytic infiltration with obliterating phlebitis but an absence of neoplastic proliferation both in the liver tumor and in the biopsy specimen of the pancreas. Abundant IgG4-positive plasma cells were seen in the lesions. This is the first case report that shows a simultaneous occurrence of hepatic IP and AIP, suggesting that these lesions appeared on the background of the recently proposed entity of IgG4-related systemic disease.

Extrapancreatic lesions in autoimmune pancreatitis

GOALS

To examine extrapancreatic lesions associated with autoimmune pancreatitis.

BACKGROUND

Autoimmune pancreatitis is a unique clinical entity proposed recently, and is reported to occasionally be associated with other autoimmune diseases.

STUDY

Extrapancreatic lesions were examined clinically, radiologically, and histologically in 25 patients with autoimmune pancreatitis.

RESULTS

Stenosis of the bile duct was observed in 22 patients (lower bile duct [n = 19], upper bile duct [n = 1], intrahepatic bile duct [n = 2]). Marked extrapancreatic bile duct wall thickening not associated with obvious cholangiographic abnormality was seen on ultrasound in 3 patients. Enlargement of the salivary glands and cervical lymph nodes was detected in 4 patients. Abdominal lymphadenopathy was observed in 5 of 8 patients at laparotomy. Retroperitoneal fibrosis was noted in 2 patients. Obliterative phlebitis of the pancreatic and peripancreatic veins was observed histologically in all 6 resected specimens. Marked stenosis of the portal vein and encasement of the peripancreatic arteries was observed in 4 and 8 of 14 patients who underwent abdominal angiography, respectively. Diabetes mellitus was diagnosed in 13 patients. All associated extrapancreatic lesions except diabetes mellitus improved after steroid therapy.

CONCLUSIONS

Extrapancreatic lesions found to be occasionally associated with autoimmune pancreatitis were stenosis of the bile duct, enlargement of the salivary glands, abdominal or cervical lymphadenopathy, retroperitoneal fibrosis, stenosis of the peripancreatic arteries or portal vein, and diabetes mellitus. It is possible that these lesions are induced by the same inflammatory mechanisms as autoimmune pancreatitis.

Clinical and pathological characteristics of Mikulicz's disease (IgG4-related plasmacytic exocrinopathy)

Mikulicz's disease (MD) has been considered part of primary Sjogren's syndrome (SS) since Morgan's report in 1953. MD represents a unique condition involving enlargement of the lacrimal and salivary glands, as is also seen in SS; however, MD is characterized by few autoimmune reaction and its good responsiveness to glucocorticoid. Recent reports have shown that the frequency of apoptosis in glands of MD patients is lower when compared with SS. This phenomenon reflects the histologically reversible gland secretion in MD. Elevated IgG4 concentrations in the serum and prominent infiltration by plasmacytes expressing IgG4 in the lacrimal and salivary glands have also been confirmed in MD. Plasma cells expressing IgG4 are also detected in lymph nodes and bone marrow. MD may be a systemic disease, rather than a lacrimal and salivary gland disease. We here propose the new entity "IgG4-related plasmacytic exocrinopathy" and expect future development with regard to its relationship with autoimmune pancreatitis, which similarly presents elevated serum IgG4 levels.

Clinical and pathological differences between Mikulicz's disease and Sjögren's syndrome

OBJECTIVE

Mikulicz's disease (MD) has been included within the diagnosis of primary Sjögren's syndrome (SS), but represents a unique condition involving enlargement of the lachrymal and salivary glands and characterized by few autoimmune reactions and good responsiveness to glucocorticoids. We have previously described elevated immunoglobulin (Ig) G4 in the serum of four patients with MD. In this paper, we accumulated more MD cases and undertook clinical and histopathological analysis of these patients to clarify differences between MD and SS.

METHODS

We diagnosed seven patients with MD according to the following criteria: (i) visual confirmation of symmetrical and persistent swelling in more than two lachrymal and major salivary glands; (ii) prominent mononuclear infiltration of lachrymal and salivary glands; and (iii) exclusion of other diseases that present with glandular swelling, such as sarcoidosis and lymphoproliferative disease. We summarized the clinical and serological characteristics (IgG subclasses and IFN-gamma/IL-4 ratio) of seven patients with MD, compared with SS with glandular swelling (SSw) and without glandular swelling (SSo). After steroid administration, we analysed changes in IgG subclasses in MD. Labial salivary gland specimens in MD, SSw and SSo were stained with anti-IgG4 antibodies.

RESULTS

The concentration (+/-s.d.) of IgG4 was 1169.7 +/- 892.2 mg/dl in MD, 24.4 +/- 7.0 mg/dl in SSw (P<0.005) and 82.6 +/- 189.7 mg/dl in SSo (P<0.005). The IFN-gamma/IL-4 ratio was 0.392 +/- 0.083 (0.78 +/- 0.23/2.14 +/- 0.31 IU/pg) in MD, 0.004 +/- 0.002 (0.20 +/- 0.07/57.02 +/- 14.05 IU/pg) in SSw (P<0.05) and 0.012 +/- 0.009 (0.58 +/- 0.86/116.24 +/- 207.65 IU/pg) in SSo (P<0.05). The concentration (+/-s.d.) of IgG4 in MD decreased to 254.0 +/- 50.3 mg/dl (P<0.05) after glucocorticoid treatment. Histopathologically, only MD was associated with prominent infiltration of IgG4-positive plasmacytes into lachrymal and salivary glands.

CONCLUSION

Mikulicz's disease is quite different from SS clinically and histopathologically. MD is suggested to be an IgG4-related systemic disease.