Pancreatic pseudotumors associated with multifocal idiopathic fibrosclerosis

Inflammatory myofibroblastic tumors of the pancreas in children: A case report and literature review

INTRODUCTION

Inflammatory myofibroblastic tumors are an uncommon neoplasm, which are very rarely located in the pancreas. Clinically and radiologically, this rare pancreatic tumor presents as an abdominal mass lesion that mimics other pancreatic tumors, and should therefore be considered in the differential diagnosis of pancreatic tumors.

CLINICAL FINDINGS AND DIAGNOSIS

The 15-year-old boy complained of abdominal pain over the left upper quadrant with intermittent fever for 7 days. Abdominal sonography revealed one cystic lesion with a hyperechoic component in the left upper quadrant of the abdomen. Surgical excision was performed and postoperative findings indicated a pancreatic tail tumor. The pathology indicated inflammatory myofibroblastic tumors. To our knowledge, this patient is a unique case as the tumor was located in the pancreatic tail only, sparing the body.

INTERVENTIONS AND OUTCOMES

The patient underwent tumor resection and segmental resection of the transverse colon with simple closure. The patient had no evidence of disease recurrence at 3 years follow-up.

CONCLUSION

Inflammatory myofibroblastic tumors of the pancreas in children are extremely rare. Surgical excision is the standard treatment, and corticosteroids use in children need more large-scale studies.

Inflammatory pseudotumours in the abdomen and pelvis: a pictorial essay

Inflammatory pseudotumours are uncommonly encountered lesions in the abdomen and pelvis that often present with variable and nonspecific imaging features. They may mimic other more common lesions, including malignancy. Within the appropriate clinical context, inflammatory pseudotumours merit consideration in the differential diagnosis of soft-tissue masses within the abdomen and pelvis. A preoperative diagnosis of inflammatory pseudotumour, established through biopsy, may help to differentiate this benign entity from malignancy. In this article, we reviewed the imaging features of inflammatory pseudotumours of the abdomen and pelvis, including liver, spleen, bowel, retroperitoneum, kidney, bladder, uterus, and adnexa.

Clinical features of a new disease concept, IgG4-related thyroiditis

OBJECTIVES

Immunoglobulin (Ig)G4-related disease is a recently proposed systemic disorder that includes autoimmune pancreatitis (AIP), Mikulicz's disease, and various other organ lesions. In the present retrospective study, we examined whether thyroid lesions should also be included in IgG4-related disease (Ig4-RD) under the new term IgG4-related thyroiditis.

METHOD

We enrolled 114 patients with Ig4-RD, including 92 patients with AIP, 15 patients with Mikulicz's disease, and seven patients with IgG4-related cholangitis, and analysed clinical findings, function, serum values of activity markers, computed tomography (CT) images, and histology of the thyroid gland.

RESULTS

Among the 22 patients (19%) in our cohort who were found to have hypothyroidism [thyroid stimulating hormone (TSH) > 4 mIU/L], 11 patients had clinical hypothyroidism [free thyroxine (FT4) < 1 ng/dL] and 11 patients had subclinical hypothyroidism (FT4 ≥ 1 ng/dL). Serum concentrations of IgG, IgG4, circulating immune complex (CIC), and β2-microglobulin (β2-MG) were significantly higher in the hypothyroidism group compared with the remaining 92 euthyroid patients, and serum C3 concentration was significantly lower. After prednisolone treatment, TSH values had decreased significantly (p = 0.005) in this group and FT4 values had increased significantly (p = 0.047). CT images showed that the thyroid glands of patients with clinical hypothyroidism had a significantly greater volume than those of the euthyroid and other groups. Pathological analysis of one resected thyroid gland disclosed a focused lesion with infiltration of lymphocytes and IgG4-bearing plasma cells and loss of thyroid follicles.

CONCLUSIONS

Thyroid lesions associated with hypothyroidism can be considered as a new disease termed IgG4-related thyroiditis. Awareness of this condition should lead to appropriate corticosteroid treatment that may prevent progression to a fibrous state.

IgG4-related sclerosing disease, an emerging entity: a review of a multi-system disease

Immunoglobulin G4-related systemic disease (IgG4-RSD) is a recently defined emerging entity characterized by a diffuse or mass forming inflammatory reaction rich in IgG4-positive plasma cells associated with fibrosclerosis and obliterative phlebitis. IgG4-RSD usually affects middle aged and elderly patients, with a male predominance. It is associated with an elevated serum titer of IgG4, which acts as a marker for this recently characterized entity. The prototype is IgG4-related sclerosing pancreatitis or autoimmune pancreatitis (AIP). Other common sites of involvement are the hepatobiliary tract, salivary gland, orbit, and lymph node, however practically any organ can be involved, including upper aerodigestive tract, lung, aorta, mediastinum, retroperitoneum, soft tissue, skin, central nervous system, breast, kidney, and prostate. Fever or constitutional symptoms usually do not comprise part of the clinical picture. Laboratory findings detected include raised serum globulin, IgG and IgG4. An association with autoantibody detection (such as antinuclear antibodies and rheumatoid factor) is seen in some cases. Steroid therapy comprises the mainstay of treatment. Disease progression with involvement of multiple organ-sites may be encountered in a subset of cases and may follow a relapsing-remitting course. The principal histopathologic findings in several extranodal sites include lymphoplasmacytic infiltration, lymphoid follicle formation, sclerosis and obliterative phlebitis, along with atrophy and destruction of tissues. Immunohistochemical staining shows increased IgG4+ cells in the involved tissues (>50 per high-power field, with IgG4/IgG ratio >40%). IgG4-RSD may potentially be rarely associated with the development of lymphoma and carcinoma. However, the nature and pathogenesis of IgG4-RSD are yet to be fully elucidated and provide immense scope for further studies.

Review article: autoimmune pancreatitis - management of an emerging disease

BACKGROUND

Autoimmune pancreatitis is a steroid-responsive inflammatory pancreatic disease considered to be part of an immunoglobulin G4 (IgG4)-associated systemic disease.

AIM

To review the management of autoimmune pancreatitis.

METHODS

We conducted a PubMed search using the following key words: autoimmune pancreatitis, IgG4-associated systemic disease, IgG4-associated cholangitis, diagnosis, natural history, treatment.

RESULTS

Although there are reports of spontaneous resolution of autoimmune pancreatitis, steroids have been shown to be effective in inducing remission, reducing the frequency of relapse and that of long-term unfavourable events compared to historical controls. There are no randomised data on autoimmune pancreatitis treatment. Oral steroids are used for induction of remission. Reported response results are excellent with variable proportions of patients achieving remission in different studies. After a period of 2-4 weeks, steroids are tapered and usually withdrawn within several months, although long-term maintenance therapy for all autoimmune pancreatitis patients has also been proposed. Disease relapse occurs in more than 40% of patients and can be effectively treated with additional immunosuppression, including azathioprine.

CONCLUSIONS

Steroids are effective in inducing remission and in treating relapse in patients with autoimmune pancreatitis. Randomised trials on autoimmune pancreatitis therapy are lacking. To date, questions concerning the timing, choice and duration of long-term immunosuppression remain unanswered.

IgG4-related meningeal disease: clinico-pathological features and proposal for diagnostic criteria

IgG4-related disease has evolved from originally being recognized as a form of pancreatitis to encompass diseases of numerous organs including the hypophysis and one reported case of dural involvement. A search of the University of Virginia, Division of Neuropathology files for 10 years identified ten cases of unexplained lymphoplasmacytic meningeal inflammation that we then evaluated using immunohistochemical stains for IgG4 and IgG. Ten control cases including sarcoidosis (4), tuberculosis (1), bacterial abscess (2), Langerhans cell histiocytosis (2), and foreign body reaction (1) were also examined. The number of IgG4-positive plasma cells was counted in five high power fields (HPFs) and an average per HPF was calculated. Cases that contained greater than ten IgG4-positive cells/HPF were considered to be IgG4-related. Five of the study cases met these criteria, including one case of leptomeningeal inflammation. All cases exhibited the typical histological features of IgG4-related disease including lymphoplasmacytic inflammation, fibrosis, and phlebitis. The dural-based lesions appear to represent a subset of the cases historically diagnosed as idiopathic hypertrophic pachymeningitis. While the leptomeningeal process most closely resembles non-vasculitic autoimmune inflammatory meningoencephalitis. Given these findings, IgG4-related meningitis should be considered in the differential diagnosis of meningeal inflammatory lesions after stringent clinical and histologic criteria are used to rule out other possible diagnoses.

IgG₄-related sclerosing disease: a novel mimic of inflammatory bowel disease

High levels of IgG₄-positive plasma cells are commonly seen in autoimmune pancreatitis. It has recently become evident that autoimmune pancreatitis is one component of a larger multi-system disease. IgG₄-positive plasma cells have been identified in many extrapancreatic tissues, including the colon, biliary tract, liver, and lungs, and thus the term "IgG₄-related sclerosing disease" has been proposed. Awareness of IgG₄-related sclerosing disease is important, as it has been shown to mimic other conditions like malignancy. This review discusses IgG₄-related colitis and its potential for mimicking inflammatory bowel disease.

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.

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.

Systemic extrapancreatic lesions associated with autoimmune pancreatitis

Autoimmune pancreatitis (AIP) is frequently associated with sclerosing cholangitis (SC). SC with AIP has a cholangiographic appearance that is often confused with primary sclerosing cholangitis (PSC) but only the former responds well to corticosteroid therapy. Detailed study of cholangiographic findings allows discrimination of SC with AIP from PSC. Band-like strictures, a beaded or pruned-tree appearance, and diverticulum-like outpouching were significantly more frequently observed in cases of PSC. In contrast, segmental strictures, dilation after confluent stricture, and strictures of the lower common bile duct were significantly more common in SC with AIP. The other systemic extrapancreatic lesions associated with AIP found in the literature were Sjögren's syndrome, ulcerative colitis, retroperitoneal fibrosis, sialadenitis, thyroiditis, and idiopathic thrombocytopenic purpura. In a comparison of the clinical course and laboratory data of our cases, gamma-globulin, IgG, and IgG4 levels were significantly higher in patients with AIP with systemic extrapancreatic lesions than those without them. In our immunohistochemical study, marked infiltration of IgG4+ plasma cells was frequently observed in the pancreas, liver, bile duct, and salivary glands of the AIP patients examined. In contrast, the degree of infiltration of IgG4+ plasma cells around the bile duct in the portal areas and the extrahepatic bile duct with PSC was significantly lower than with AIP. These results also suggest that AIP is a disease state clearly different from PSC. In addition, the normal epithelia of the pancreatic ducts, bile ducts, gallbladder, and salivary gland ducts reacting with the patients' sera was detectable by the anti-IgG4 antibody. Therefore, AIP may also affect extrapancreatic organs, and the sera of AIP patients may contain an IgG4 autoantibody to various organs.

Autoimmune pancreatocholangitis: a series of ten patients

BACKGROUND

During a 10-year period we observed 10 patients who suffered from an inflammatory-fibrosing disease mimicking pancreatic carcinoma and primary sclerosing cholangitis (PSC).

METHODS

A review of the presenting features, the clinical course and the relevant literature.

RESULTS

Ten male patients (mean age 55 years) presented with weight loss, jaundice and pruritus. Pancreatic cancer was suggested by imaging studies, which showed focal or generalized pancreatic enlargement and compression of the distal common bile duct. Cholangiography also demonstrated intrahepatic biliary stenoses consistent with sclerosing cholangitis. None had evidence of IBD. Exocrine pancreatic insufficiency was found in six cases and diabetes in four. Pancreatic histology (n=3) showed fibrosis and extensive inflammatory infiltrates. Immunosuppressive treatment was instituted in five patients. Clinical and biochemical remission occurred in three; in one other patient, previously documented intrahepatic biliary strictures had disappeared after 3 months. One patient had concomitant Sjögren's disease. The clinical features, pancreatic involvement, age at presentation, absence of IBD and response to steroids all plead against a diagnosis of "classical" PSC. The natural course of the disease was highly variable. Thirty-five comparable cases, with a largest series of three, have been reported in the literature. The disease has been associated with Sjögren's disease, retroperitoneal fibrosis and other fibrosing conditions, and may be a manifestation of a systemic fibro-inflammatory disorder.

CONCLUSION

Autoimmune pancreatocholangitis is a distinct inflammatory disorder involving the pancreas and biliary tree. The disease may mimick pancreatic carcinoma and PSC and responds to immunosuppressives.

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--a surgical disease?]

The term autoimmune pancreatitis (AIP) describes a nonalcoholic, chronic lymphoplasmocytic pancreatitis. The lymphoplasmocytic infiltration is characterized by periductal localization of predominantly CD4-positive T cells, fibrosis, and acinar atrophy, frequently resulting in stenosis of the main pancreatic and distal common bile ducts. Imaging studies often reveal a diffuse narrowing of the pancreatic main duct and swelling of the pancreatic head wrongly suggesting the presence of a malignant tumor. Clinical signs include mild abdominal pain, jaundice, recurrent episodes of acute pancreatitis, and even new-onset diabetes mellitus. Additionally, AIP can be associated with other autoimmune diseases such as Sjögren's syndrome, primary sclerosing cholangitis, chronic inflammatory bowel diseases, and retroperitoneal fibrosis. Serological markers include autoantibodies and increased levels of gamma globulin and especially IgG4. Steroids seem to be effective in improving clinical symptoms as well as in the resolution of pancreatic and bile duct narrowing. This distinguishes AIP from other forms of pancreatitis and from pancreatic neoplasms. Further studies of the underlying pathophysiologic mechanisms, prognosis, and new diagnostic tools are needed to provide adequate and effective treatment in the future. In this article, we summarize the current knowledge about AIP and present 17 cases that underwent surgical resection at our institution from 2003 to 2004.

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.

Pancreatic pseudotumors: non-neoplastic solid lesions of the pancreas that clinically mimic pancreas cancer

In the pancreas, a variety of non-neoplastic conditions may form solid masses that may mimic cancer. Up to 5% of pancreatectomies performed with the preoperative clinical diagnosis of carcinoma will prove to be non-neoplastic by pathologic examination, although this figure is decreasing with improved diagnostic modalities. Chronic inflammatory lesions are the leading cause of this phenomenon ("pseudotumoral pancreatitis"), and among these, autoimmune and paraduodenal pancreatitides (discussed separately in this issue) are most important. In this article, we will focus on the noninflammatory lesions that may form tumor-like lesions of the pancreas. Adenomyomatous hyperplasia of ampulla of Vater is a subtle lesion that is difficult to define; larger examples (>5 mm) have been found to be the cause of obstructive jaundice. Accessory (heterotopic) spleen may form a well-defined nodule within the tail of the pancreas and is typically mistaken for endocrine neoplasm. Lipomatous hypertrophy is the replacement of pancreatic tissue with mature adipose tissue that occasionally leads to moderate to marked enlargement of the pancreas. Hamartomas are very rare if the entity is defined strictly. They are characterized by irregularly arranged mature pancreatic elements admixed with stromal tissue. A cellular, spindle-cell variant with c-kit (CD117) expression is recognized. Pseudolymphoma forms well-defined nodules composed of hyperplastic lymphoid tissue. Rarely, foreign-body deposits, granulomatous inflammations (such as sarcoidosis or tuberculosis), and congenital lesions may form tumoral lesions. In conclusion, it is important to recognize the types of conditions that form pseudotumors in the pancreas so that they can be distinguished from ductal adenocarcinomas, especially clinically, but also pathologically. Nonspecific terms such as "inflammatory pseudotumor" ought to be avoided, and every attempt should be made to classify a "pseudotumor" into a more specific diagnostic category discussed above.

Diagnostic features and differential diagnosis of autoimmune pancreatitis

A clinically and pathologically distinct form of chronic pancreatitis is now widely recognized and has been designated variably as lymphoplasmacytic sclerosing pancreatitis, duct-destructive (duct-centric) pancreatitis or autoimmune pancreatitis. This entity is currently defined by a constellation of clinical and pathologic findings, including the lack of both conventional risk factors for pancreatitis, such as alcohol use and gallstones, and their hallmark pattern of injury, including calcifications and pseudocysts. Histologically, it is characterized by lymphoplasmacytic inflammation with abundant IgG4-positive plasma cells that exhibit an affinity for ducts as well as venules ("peri-venulitis," with or without frank vasculitis). Inflammation is often associated with sclerosis and expansion of periductal tissue. In some cases, fibroblastic activity is prominent and resembles "inflammatory pseudotumor" or is even misdiagnosed as "inflammatory myofibroblastic tumor." In what appears to be a distinct subset of this entity, intraepithelial granulocytic infiltrates may be seen. Well-developed examples are readily recognized; however, lesser ones may be difficult to distinguish from other forms of pancreatitis based on morphology alone. This type of pancreatitis is considered an autoimmune process. In about 15% to 20% of patients, the clinical stigmata of autoimmune conditions are present at the time of diagnosis, and in many others, discovered subsequently. The usual "lymphoplasmacytic sclerotic" type tends to be associated with Sjogren, whereas the "granulocytic" subset, with inflammatory bowel disease. Most patients present with a pancreatic head mass, often with an accompanying stricture of the distal common bile duct, which thus radiologically resembles "pancreas cancer." In fact, this entity accounts for more than a third of the cases of pseudotumoral pancreatitis (mass-forming inflammatory lesions that resemble carcinoma). Elevated serum IgG4 levels are characteristic and may be very helpful in the differential diagnosis from tumors and tumor-like lesions of the pancreas which seldom result in levels above 135 mg/dL. The mean age of the patients with this condition is in the mid-50s; the subset with granulocytic intraepithelial lesions seem to be younger (mid 40s). Despite the autoimmune association, males are afflicted as commonly as (if not more than) females. Following resection, emergence of new fibro-inflammatory lesions in the remaining pancreaticobiliary tree has been noted in some cases; however, the process typically responds to steroids. It is important to recognize the distinctive clinicopathologic features of this entity, so that it can be diagnosed accurately and managed appropriately.

Systemic extrapancreatic lesions associated with autoimmune pancreatitis

OBJECTIVES

Autoimmune pancreatitis (AIP) is often associated with systemic extrapancreatic lesions. We studied 31 cases of AIP to clarify the diversity of associated systemic extrapancreatic lesions and the differences between AIP with and without systemic extrapancreatic lesions.

METHODS

The clinical features and courses were compared by age, sex, and blood chemistry between those with and without systemic extrapancreatic lesions. In addition, we reviewed the available literature on systemic extrapancreatic lesions with AIP.

RESULTS

Seven of the 31 cases of AIP had associated systemic extrapancreatic lesions, which were diagnosed simultaneously with AIP; however, 1 case presenting with various extrapancreatic lesions was diagnosed independently of the AIP lesion. Patients with systemic extrapancreatic lesions needed maintenance steroid therapy for AIP in 4 cases and systemic extrapancreatic lesions in 2 cases; the ratio of cases requiring maintenance steroid therapy was significantly higher among those with systemic extrapancreatic lesions (6/8) than those without (7/23). There were no significant differences between groups with regard to age, sex, extent of narrowing of the main pancreatic duct, and enlargement of the pancreas. gamma-globulin, IgG, and IgG4 levels were significantly higher in patients with AIP with systemic extrapancreatic lesions than those without. The systemic extrapancreatic lesions associated with AIP found in the literature were Sjögren syndrome, ulcerative colitis, retroperitoneal fibrosis, sialadenitis, thyroiditis, and idiopathic thrombocytopenic purpura.

CONCLUSIONS

The results of this study suggest that, when encountering a case of AIP with elevated levels of gamma-globulins, IgG, and IgG4, an effort should be made to detect other systemic extrapancreatic abnormalities and initiate steroid administration.

Immunohistochemical study of autoimmune pancreatitis using anti-IgG4 antibody and patients' sera

AIMS

Autoimmune pancreatitis (AIP), characterized by raised serum IgG4 levels, is frequently complicated by disorders of extrapancreatic organs. The aim of the present study was to examine immunohistochemically which extrapancreatic organs are affected, and whether an autoantibody to such organs is present in the serum of AIP patients.

METHODS

Various tissues/organs obtained from AIP patients were studied immunohistochemically with an anti-IgG4 antibody. To examine the presence of an autoantibody in the serum of AIP patients, sera were incubated with various normal organs/tissues extracted for other diseases, followed by detection with an anti-IgG4 antibody. Sera were also examined before and after glucocorticoid therapy.

RESULTS

Marked infiltration of IgG4+ plasma cells was observed in the pancreas, liver, bile duct and salivary gland of many of the AIP patients examined. The normal epithelia of the pancreatic ducts, bile ducts, gallbladder and salivary gland ducts reacting with the patients' sera were detectable by the anti-IgG4 antibody. Following glucocorticoid therapy the IgG4 antibody from the patients' sera showed decreased reactivity with these tissues.

CONCLUSIONS

AIP may also affect extrapancreatic organs, the serum of AIP patients may contain an IgG4 autoantibody to various organs and glucocorticoid therapy may improve such disorders.

High prevalence of hypothyroidism in patients with autoimmune pancreatitis

Autoimmune pancreatitis is a unique form of chronic pancreatitis and has been correlated with various extrapancreatic lesions. To search for a correlation between autoimmune pancreatitis and thyroid lesions, we measured thyroid functions in 41 patients with autoimmune pancreatitis and in 41 patients with chronic calcifying pancreatitis and investigated the correlation between HLA antigens and hypothyroidism. We found a significant difference in the prevalence of antithyroglobulin antibody and hypothyroidism between patients with autoimmune pancreatitis and those with chronic pancreatitis (34.1 vs. 7.3%, P = 0.005, and 26.8 vs. 0%, P = 0.0005, respectively). Patients with hypothyroidism had a significantly higher frequency of antithyroglobulin antibody (63.6%) than those without hypothyroidism but showed no differences in other findings, including serum IgG4 concentration. We could find no significant association between any HLA antigens and the hypothyroid state of autoimmune pancreatitis. One quarter of the patients with autoimmune pancreatitis have hypothyroidism that may be independent of the active state of the pancreatic lesion or systemic fibrosing disorder, and thus patients suspected of having autoimmune pancreatitis should be evaluated for possible hypothyroidism.

Lymphoplasmacytic sclerosing (autoimmune) pancreatitis

Lymphoplasmacytic sclerosing pancreatitis (LPSP), also known as autoimmune pancreatitis or nonalcoholic, duct destructive chronic pancreatitis, has been increasingly recognized in the past decade as a histologically distinctive type of pancreatitis that affects middle-aged patients who lack the typical risk factors for chronic pancreatitis (alcohol abuse in particular). LPSP is sometimes associated with other autoimmune diseases or fibroinflammatory lesions, although in some patients, pancreatic and biliary involvement represent the only known disease process. Many patients present with pancreatic masses clinically and radiographically simulating pancreatic carcinoma, and associated bile duct strictures enhance the resemblance. Elevated serum IgG4 levels have been described in patients with LPSP and have been used to distinguish LPSP from pancreatic carcinoma preoperatively. Although there is some heterogeneity of pathologic findings, resected cases of LPSP typically demonstrate dense periductal lymphoplasmacytic inflammation, periductal and parenchymal fibrosis, and obliterative venulitis; neutrophilic infiltration of the ductal epithelium ("granulocytic epithelial lesions") may also occur. Large tumor-like masses of fibroinflammatory tissue ("reactive fibroinflammatory pseudotumors") may develop and extend beyond the pancreas. Following surgical resection, a few patients suffer recurrence of fibroinflammatory lesions in the pancreatobiliary tree, or they may develop other manifestations of autoimmune disease elsewhere in the body. However, the overall prognosis is excellent. Response to steroid therapy has been noted. Current studies are focusing on identifying additional preoperative diagnostic tests and on characterizing possible variants of LPSP. This review presents the defining clinical and pathologic features of LPSP and discusses the ongoing efforts to understand the pathogenesis of this disease.

Histopathological features of diagnostic and clinical relevance in autoimmune pancreatitis: a study on 53 resection specimens and 9 biopsy specimens

BACKGROUND AND AIMS

Autoimmune pancreatitis seems to be a disease with a heterogeneous appearance. Our intention was to establish key diagnostic criteria, define grades of severity and activity, identify features of potential subtypes and evaluate the diagnostic relevance of biopsy specimens.

METHODS

Histopathological criteria and clinical features were recorded in pancreatic resection specimens from 53 patients who were found to have chronic pancreatitis lacking pseudocysts, calculi, irregular duct dilatations, pancreas divisum and/or duodenal wall inflammation. The severity of the chronic inflammation was graded, and the activity of the acute inflammatory component and the granulocytic epithelial lesion (GEL) were determined. Additionally, pancreatic biopsy specimens from 9 patients with suspected AIP were assessed.

RESULTS

Periductal lymphoplasmacytic infiltration was identified in all cases, followed in order of frequency by periductal fibrosis and venulitis. These changes were absent in 147 pancreatic specimens that showed chronic pancreatitis associated with pseudocysts, calculi, pancreas divisum and/or duodenal wall inflammation. In 90% of the cases, these chronic changes were graded as 3 or 4. In 81%, the inflammatory process resided in the head of the pancreas and involved the common bile duct. GELs were present in 42% of the patients, who had a mean age of 40.5 years, an almost equal male-female ratio and a high coincidence of ulcerative colitis or Crohn's disease. Patients without GELs were older (mean age 64 years), showed a male preponderance, commonly had Sjogren's syndrome and often developed recurrent bile-duct stenosis. Diagnostically relevant lesions were present in two of five wedge biopsy specimens and three of four fine-needle specimens.

CONCLUSIONS

Periductal lymphoplasmacytic infiltration and fibrosis, preferential occurrence in the pancreatic head and venulitis characterize autoimmune pancreatitis. GELs predominantly occur in a subset of patients who are younger, more commonly have ulcerative colitis and Crohn's disease and seem to have fewer recurrences than patients without GELs. Pancreatic biopsy material proved to be a very helpful adjunct for establishing the diagnosis.

Autoimmune chronic pancreatitis

In recent years a peculiar type of chronic pancreatitis with underlying autoimmunity has been described. Lymphoplasmacytic infiltration and fibrosis on histology and elevated IgG levels or detected autoantibodies on laboratory data support the concept of autoimmune chronic pancreatitis (AIP). Pancreatic imaging reveals a rare association of diffuse enlargement of the pancreas and irregular narrowing of the main pancreatic duct, which is unique and specific to AIP. Although AIP is not a common disease, it is increasingly being recognized as knowledge of this entity builds up. Clinically it is very important to be aware of this disease because AIP can clinically disguise as pancreaticobiliary malignancies, ordinary chronic, or acute pancreatitis. Above all, AIP is a very attractive disease to clinicians in terms of its dramatic response to oral steroid therapy in contrast to ordinary chronic pancreatitis. This review discusses the clinical, laboratory, histologic, and imaging findings that are seen in patients with AIP, especially focusing on the diagnosis.

Laparoscopic distal pancreatectomy for inflammatory pseudotumor of the pancreas

An 82-year-old woman presented with abdominal pain, nausea, emesis, and weight loss of ~25 lb over 6 months. A CT scan and MRI of the abdomen revealed a mass in the tail of the pancreas that was suspicious for malignancy. The patient underwent successful laparoscopic distal pancreatectomy and was discharged home on the 4th postoperative day after an uneventful course. Pathology revealed an inflammatory pseudotumor of the pancreas (IPT). Pancreatic IPT is a rare entity, and this case represents the first report of laparoscopic resection of this lesion. The presentation, diagnosis, histologic features, and therapy of IPT of the pancreas are reviewed.

Involvement of the biliary system in autoimmune pancreatitis: a follow-up study

BACKGROUND & AIMS

The aim of this study was to define the bile duct changes associated with autoimmune pancreatitis.

METHODS

Eight patients with autoimmune pancreatitis were followed for a mean of 4 years. The clinical features of these patients, including extrapancreatic bile duct changes, were examined by using biochemical parameters and several imaging modalities. Pathologic features of the pancreas and liver were examined by using the biopsy specimens of 7 patients.

RESULTS

Diffuse or focal narrowing of the main pancreatic duct was observed in all patients. Histologic examination of the pancreas showed lymphoplasmacyte infiltration with severe fibrosis and acinar cell depletion. In 6 patients extrapancreatic bile duct changes such as stricture of the bile duct at hilus or intrahepatic area were observed. In 2 patients abnormalities in the bile duct and pancreas were detected simultaneously at diagnosis, and changes in the bile duct were observed later in 4 patients. Lymphoplasmacyte infiltration and fibrosis were observed in the portal area of all 7 liver biopsy samples. Five of the patients with bile duct changes received steroid therapy, and the pathological changes improved.

CONCLUSIONS

Extrapancreatic bile duct changes are frequently associated with autoimmune pancreatitis. Similar pathogenic mechanism might produce the biliary tract and pancreatic abnormalities in autoimmune pancreatitis resulting in a similar histopathology in the liver and pancreas and response to steroid therapy.

CT appearance of gastric involvement in multifocal idiopathic fibrosclerosis

Multifocal idiopathic fibrosclerosis (also called multifocal fibrosclerosis) is an uncommon disease in which there is a systemic overgrowth of fibrous tissues, with a spectrum of aggressiveness ranging from benign retroperitoneal fibrosis to pachymeningitis. We describe the first case of gastric involvement of multifocal fibrosclerosis and its appearance on CT.

Inflammatory Pseudotumor Presenting as a Cystic Tumor of the Pancreas

Inflammatory pseudotumor (IPT) of the pancreas occurs rarely. Eighteen cases have been described in the English literature. In all previous patients IPT of the pancreas presented as solid pancreatic mass. We are reporting a case of IPT presenting as a cystic mass of the pancreas, which has not been described previously. A review of IPT of the pancreas and a discussion regarding the management of pancreatic cystic neoplasm is provided.

Sclerosing pancreato-cholangitis responsive to steroid therapy

Four patients with weight loss, jaundice, a sonolucent swelling of the pancreas, and multiple bile-duct strictures are described. These cases of sclerosing pancreato-cholangitis responded to steroid therapy.

Stenosis of the common bile duct due to Ormond's disease: case report and review of the literature

In a 46-year-old man endoscopic retrograde cholangiopancreatography and computed tomography scan showed a stenosis of the common bile duct by a hypodense mass highly suggestive of a Klatskin tumor. Histologic examination of the resected tumor revealed only non-specific inflammatory, fibrotic tissue without any evidence of malignancy. Three months later, the patient presented with hydronephrosis of the left kidney. Computed tomography scan showed a retroperitoneal mass with encasement of the left ureter. A percutaneous nephrostomy was performed and immunosuppressive therapy with prednisolone and azathioprine was initiated. Under this medication, almost complete regression of the pelvic mass and reopening of the ureter were observed within 3 weeks. Eight months later, azathioprine was withdrawn and prednisolone was tapered continuously to a dose less than 10 mg/day. After a follow-up of 2 years, the patient is still well. Although the histologic findings were non-specific, further evaluation of this case suggests that Ormond's disease was responsible for the tumor that had to be resected.

Chronic sclerosing sialadenitis of the submandibular gland associated with idiopathic retroperitoneal fibrosis

We report a case of a 57-year-old man who developed a fibrosclerosing lesion in the submandibular gland and idiopathic retroperitoneal fibrosis (IRF) involving the unilateral periureteral region within a year. Both lesions were resected surgically because of the suspicion of neoplasm. Pathologic examination revealed similar histologic and immunohistochemical features for both lesions, namely, fibrosclerosis with prominent hyalinizing collagen bundles and proliferation of myofibroblastic cells, and a non-neoplastic reactive nature. There was infiltration by lymphocytes with prominent lymph follicles, plasma cells and macrophages. The histologic and immunohistochemical findings suggest that the two lesions were of a similar pathogenesis, which was possibly mediated by macrophages. We think that the present case may be an unusual form of multifocal fibrosclerosis. Although sialolithiasis is thought to be a major pathogenic factor for chronic sclerosing sialadenitis of the submandibular gland, the present case suggests that certain cases might have an etiology similar to IRF.

Diffuse pancreatic fibrosis: an uncommon feature of multifocal idiopathic fibrosclerosis

Multifocal idiopathic fibrosclerosis (MIF) is a rare syndrome characterized by exuberant fibrosis involving diverse organ systems. MIF is manifest by varying combinations of the following conditions: mediastinal fibrosis, retroperitoneal fibrosis, orbital pseudotumor, Riedel's thyroiditis, and sclerosing cholangitis. Less common features of MIF include Dupuytren's contractures, lymphoid hyperplasia, Peyronie's disease, vasculitis, testicular fibrosis, and pachymeningitis. Fibrosis arising from the pancreas has been previously described in two patients with MIF. We report a 58-yr-old white man with MIF manifest as orbital pseudotumor, sclerosing cholangitis, lymph node hyperplasia, and diffuse pancreatic fibrosis.

Sclerosing pancreatitis showing rapidly progressive changes with recurrent mass formation

CONCLUSION

Sclerosing pancreatitis might develop repeatedly or might rapidly extend to the whole pancreas with recurrent mass formation.

BACKGROUND

Nothing is known concerning course or development of sclerosing pancreatitis.

METHODS

A 63-yr-old male was followed up for 2.5 yr.

RESULTS

The patient was admitted because of a tumor in the body and tail of the pancreas. Serum pancreatic enzymes were transiently elevated, but tumor markers were all negative. Imaging studies showed a tumor 7 cm in size. The main pancreatic duct was normal in the head and obstructed at the body on endoscopic retrograde pancreatography (ERCP). The K-ras oncogene mutation was positive in pure pancreatic juice. Distal pancreatectomy was performed because pancreatic cancer was highly suspected. Pathological findings showed that the tumor was a densely fibrotic mass without malignant cells. Inflammatory cell infiltration was observed in the stroma. One year later, another mass 3 cm in size was noted in the remnant pancreatic head. ERCP revealed diffuse irregular narrowing of the main pancreatic duct, its branches, and the common bile duct. Liver dysfunction improved and an elevation of serum pancreatic enzymes subsided without any specific treatment, and the mass diminished in size. The patterns of various imaging studies on the second tumor were the same as those of the previous resected mass. Corticosteroid was not administered.

Lymphadenopathy in sclerosing cholangitis: pitfall in the diagnosis of malignant biliary obstruction

We retrospectively reviewed abdominal computed tomographic (CT) studies from 20 patients with sclerosing cholangitis and found evidence of abdominal lymphadenopathy in 13 patients. Enlargement occurred primarily in areas draining the liver, such as the gastrohepatic ligament or celiac axis (N = 8), the porta hepatis (N = 7), and the pancreaticoduodenal region (N = 2). One patient had reactive adenopathy and retroperitoneal fibrosis. The presence of benign reactive lymphadenopathy in at least one intraabdominal location was confirmed by pathological examination of excised lymph nodes in seven patients. Malignancy was excluded by surgical exploration or clinical follow-up. We conclude that enlarged lymph nodes are a common finding by CT in patients with sclerosing cholangitis. Enlarged reactive lymph nodes in this condition should not be mistaken for evidence of periportal metastasis or cholangiocarcinoma.

Lymphoplasmacytic sclerosing pancreatitis with cholangitis: a variant of primary sclerosing cholangitis extensively involving pancreas

Pancreatic involvement in primary sclerosing cholangitis (PSC) is an extremely rare condition, and its pathologic features are poorly documented. We report two cases of an unusual lymphoplasmacytic sclerosing inflammatory disease involving the total pancreas, common bile duct, gallbladder, and, in one patient, the lip. Two elderly men presented with waxing and waning obstructive jaundice, and exhibited radiologic and ultrasonographic findings highly suggestive of pancreatic carcinoma. Gross appearance of the pancreas showed firm and mass-like enlargement with regional lymph node swelling. Histologic findings were characterized by diffuse lymphoplasmacytic infiltration with marked interstitial fibrosis and acinar atrophy, obliterated phlebitis of the pancreatic veins, and involvement of the portal vein. Similar inflammatory processes involved the bile duct and the gallbladder. Lymphoplasmacytic sclerosing pancreatitis with cholangitis is thought to be a more appropriate term for this condition, of which a similar lesion has been previously noted in a single case of "PSC involving pancreas". Differences in age, radiologic appearance, and the negative history of ulcerative colitis exist, but the two cases in this study could be considered as a variant of PSC extensively involving pancreas, which can readily be mistaken for pancreatic carcinoma.