Autoimmune pancreatitis accompanied by cholecystitis, periaortitis and pseudotumors of the liver

Isolated IgG4-related cholecystitis with localized gallbladder wall thickening mimicking gallbladder cancer: a case report and literature review

BACKGROUND

IgG4-related cholecystitis, which is a manifestation of IgG4-related disease in the gallbladder, is associated with autoimmune pancreatitis or IgG4-related sclerosing cholangitis in most cases; isolated gallbladder lesions without systemic manifestations are very rare. Gallbladder wall thickening is often diffuse, but sometimes localized, in which case, differentiation from gallbladder cancer becomes difficult. The characteristic features of IgG4-related cholecystitis on imaging that would enable differentiation from gallbladder cancer remain poorly described.

CASE PRESENTATION

We present a rare case of isolated IgG4-related cholecystitis with localized gallbladder wall thickening that was clinically difficult to distinguish from malignancy before resection. An 82-year-old man was referred to our hospital because of gallbladder wall thickening on abdominal ultrasonography without any symptoms. Dynamic computed tomography of the abdomen showed localized wall thickening from the body to the fundus of the gallbladder that was enhanced from an early stage with a prolonged contrast effect. There were no other findings, such as pancreatic enlargement and bile duct dilatation. Magnetic resonance cholangiopancreatography revealed neither dilatation nor stenosis of the bile duct and pancreatic duct. Endoscopic ultrasonography (EUS) showed a smooth layered thickening of the gallbladder wall with a maximum thickness of 6 mm and a well-preserved outermost hyperechoic layer in the same area. Laparoscopic cholecystectomy was performed because malignancy could not be completely ruled out. Pathological examination of a resected specimen revealed IgG4-positive plasma cell infiltration, fibrosis, and phlebitis. Although the serum IgG4 level measured after resection was normal, the condition was ultimately diagnosed as probable IgG4-related cholecystitis according to the 2020 revised comprehensive diagnostic criteria for IgG4-related disease. The EUS images reflected the pathological findings, in which lymphocytic infiltration was distributed in a laminar fashion in the gallbladder wall.

CONCLUSIONS

Although rare, isolated IgG4-related cholecystitis with localized wall thickening mimicking gallbladder cancer remains a clinical problem. A smooth laminar thickening of the gallbladder wall on EUS imaging could be one of the most informative characteristics for differentiating IgG4-related cholecystitis from gallbladder cancer.

Gallbladder wall thickening in patients with IgG4-related diseases, with special emphasis on IgG4-related cholecystitis

OBJECTIVES

Gallbladder (GB) wall thickening sometimes occurs in patients with autoimmune pancreatitis (AIP), a condition for which the name, IgG4-related cholecystitis, was proposed. We examined the radiological findings of the GB in patients with IgG4-related diseases and clinical features of patients with GB wall thickening and presented a hypothesis of its pathogenesis.

MATERIALS AND METHODS

GB wall thickening was defined by thickness ≥ 4 mm. GB wall thickness was examined in 258 patients with IgG4-related disease. Clinical and imaging findings of 200 patients with AIP with and without GB wall thickening were then compared.

RESULTS

GB wall thickening was detected in 58 patients (29%) with AIP and two patients with isolated IgG4-related sclerosing cholangitis. In the 60 GBs examined, wall thickening was diffuse, with the walls possessing a smooth inner surface. No GB wall thickening was detected among the 56 patients with IgG4-related disease without AIP or IgG4-related sclerosing cholangitis. Bile duct stenosis was detected in 56 patients (97%) with AIP with GB wall thickening. Intraductal ultrasonography indicated cystic duct wall thickening connected to bile duct wall thickening in 11 of 14 (79%) patients with AIP or IgG4-related sclerosing cholangitis with GB wall thickening. Forty-eight patients in whom IgG4-related cholecystitis was diagnosed experienced resolution of the GB wall thickening after receiving steroid therapy.

CONCLUSIONS

Most cases of GB wall thickening in IgG4-related diseases are closely associated with IgG4-related sclerosing cholangitis and may be a manifestation of IgG4-related disease throughout the biliary tract, including the bile duct, cystic duct, and GB.

Clinical and Image Characteristics of IgG4-Related Sclerosing Cholecystitis

Since autoimmune pancreatitis (AIP) was established as a new disease entity, sclerosing change with abundant immunoglobulin-4 (IgG4)-positive plasma cells, storiform fibrosis, and obliterative phlebitis are main pathological features in IgG4-related diseases. Regarding IgG4-related sclerosing cholecystitis (IgG4-CC), which is occasionally associated with AIP cases and is rarely isolated, there are no diagnostic criteria and insufficient perceptions of the image findings. Although there have been some reports on IgG4-CC, differentiation between IgG4-CC and gallbladder cancer is very difficult in some cases with a localized lesion. In this review, we especially focused on image findings of IgG4-CC and summarized its image features for diagnostic assistance. The ultrasonography and CT findings of IgG4-CC could be classified into diffuse and localized types. Based on these findings, the presence of wall thickening with an intact or smooth mucosal layer, followed by a homogenously thickened outer layer, would be a helpful morphological finding to distinguish IgG4-CC from gallbladder cancer.

Comparison of five-phase computed tomography images of type 1 autoimmune pancreatitis and pancreatic cancer: Emphasis on cases with atypical images

BACKGROUND/OBJECTIVES

International consensus diagnostic criteria (ICDC) include characteristic images of autoimmune pancreatitis (AIP); however, reports on atypical cases are increasing. The aims of this study were to compare CT findings between AIP and pancreatic cancer (PC), and to analyze type 1 AIPs showing atypical images.

METHODS

Five-phase CT images were compared between 80 type 1-AIP lesions and 80 size- and location-matched PCs in the case-control study. Atypical AIPs were diagnosed based on the four ICDC items.

RESULTS

ICDC items were recognized in most AIP lesions; pancreatic enlargement (87.7%), narrowing of the main pancreatic duct (98.8%), delayed enhancement (100%), and no marked upstream-duct dilation (97.5%). CT values of AIPs increased rapidly until the pancreatic phase and decreased afterward, while those of PCs gradually increased until the delayed phase (P < 0.0001). Atypical images were recognized in 14.8% of AIPs, commonly without pancreatic enlargement (18.5 mm) and sometimes mimicking intraductal neoplasms. The CT values and their ratios were different between atypical AIPs and size-matched PCs most significantly in the pancreatic phase, but similar in the delayed phase.

CONCLUSIONS

Ordinary type 1 AIPs can be diagnosed with the ICDC, but atypical AIPs represented a small fraction. "Delayed enhancement" is characteristic to ordinary AIPs, however, "pancreatic-phase enhancement" is more diagnostic for atypical AIPs.

Steroid Therapy and Steroid Response in Autoimmune Pancreatitis

Autoimmune pancreatitis (AIP), a unique subtype of pancreatitis, is often accompanied by systemic inflammatory disorders. AIP is classified into two distinct subtypes on the basis of the histological subtype: immunoglobulin G4 (IgG4)-related lymphoplasmacytic sclerosing pancreatitis (type 1) and idiopathic duct-centric pancreatitis (type 2). Type 1 AIP is often accompanied by systemic lesions, biliary strictures, hepatic inflammatory pseudotumors, interstitial pneumonia and nephritis, dacryoadenitis, and sialadenitis. Type 2 AIP is associated with inflammatory bowel diseases in approximately 30% of cases. Standard therapy for AIP is oral corticosteroid administration. Steroid treatment is generally indicated for symptomatic cases and is exceptionally applied for cases with diagnostic difficulty (diagnostic steroid trial) after a negative workup for malignancy. More than 90% of patients respond to steroid treatment within 1 month, and most within 2 weeks. The steroid response can be confirmed on clinical images (computed tomography, ultrasonography, endoscopic ultrasonography, magnetic resonance imaging, and 18F-fluorodeoxyglucose-positron emission tomography). Hence, the steroid response is included as an optional diagnostic item of AIP. Steroid treatment results in normalization of serological markers, including IgG4. Short- and long-term corticosteroid treatment may induce adverse events, including chronic glycometabolism, obesity, an immunocompromised status against infection, cataracts, glaucoma, osteoporosis, and myopathy. AIP is common in old age and is often associated with diabetes mellitus (33-78%). Thus, there is an argument for corticosteroid therapy in diabetes patients with no symptoms. With low-dose steroid treatment or treatment withdrawal, there is a high incidence of AIP recurrence (24-52%). Therefore, there is a need for long-term steroid maintenance therapy and/or steroid-sparing agents (immunomodulators and rituximab). Corticosteroids play a critical role in the diagnosis and treatment of AIP.

Ectopic relapse of IgG4-related disease presenting as IgG4-related sclerosing cholecystitis: A case report and review of literature

RATIONALE

Immunoglobulin (Ig) G4-related disease (IgG4-RD) is a chronic inflammatory disorder characterized by high levels of serum IgG4, swollen organs with fibrosis and abundant infiltration of IgG4-positive plasmacytes.

PATIENT CONCERNS

An 82-year-old male visited our hospital for an evaluation of a pancreatic enlargement and a bilateral submandibular adenopathy. Further investigation revealed elevation of serum IgG4 and bilateral lacrimal submandibular adenopathy. We diagnosed him with IgG4-related disease (IgG4-RD) and started administration of corticosteroid (CS) therapy. Both pancreatic enlargement and adenopathy rapidly improved; however, there was a new occurrence of diffuse wall thickening of the gallbladder during CS treatment.

DIAGNOSIS

Radiological examination revealed diffuse wall thickening of the gallbladder, and its inner layer was smooth and homogenous. These findings suggested an inflammatory change, but the possibility of malignancy could not be excluded.

INTERVENTIONS

The patient underwent laparoscopic cholecystectomy for a pathological diagnosis.

OUTCOMES

Histological examination revealed a transmural infiltration of IgG4 positive plasma cells and dense fibrosis. The patient was pathologically diagnosed with IgG4 related cholecystitis presenting as an ectopic relapse.

LESSONS

There are 2 major types of IgG4-related cholecystitis, a diffuse wall thickening type and a mass formation type. It is sometimes difficult to differentiate IgG4-related cholecystitis with gallbladder cancer.Corticosteroid (CS) is effective for induction of remission; however, we sometimes encounter disease relapse after reduction of CS dose. We should be mindful that some patients may relapse with new organ involvements even if the primary site and serum IgG4 level are well controlled.

A case of IgG4-related hepatic inflammatory pseudotumor replaced by an abscess after steroid treatment

BACKGROUND

Hepatic inflammatory pseudotumor (IPT) is a rare disease which often mimics a malignant tumor and is therefore often misdiagnosed and surgically resected. Recently, a concept of IgG4-related diseases (IgG4-RD) has been proposed that is becoming widely recognized and includes IgG4-related hepatic IPT. Corticosteroids are widely accepted as the standard treatment.

CASE PRESENTATION

A 72-year-old Japanese man, who had been followed for ten years after surgery and chemotherapy for treatment of hilar and lower bile duct cancers, developed intermittent fever and abdominal pain and visited this hospital. Blood examinations revealed an inflammatory reaction, worsened glucose intolerance, and an increased level of serum IgG4 (137 mg/dL). Computed tomography (CT) revealed a 5 cm-sized mass in hepatic segment 7. Because of his cancer history, not only was a benign mass suspected, but there was also the possibility of a recurrent biliary malignancy. Liver biopsy was performed and the histology met the criteria for IgG4-related IPT. Corticosteroid therapy was initiated and his symptoms quickly resolved. However, two months later, a repeat CT demonstrated that the hepatic mass had been replaced by an abscess. The abscess was initially refractory, despite tapering corticosteroid treatment, controlling diabetes by intensive insulin therapy, administration of antibiotics, and percutaneous abscess drainage. Finally, after six months, the condition resolved.

CONCLUSION

The diagnosis of hepatic IPT is sometimes difficult. To differentiate it from a malignant tumor, histological examination is necessary. Although corticosteroids are recognized as the standard therapy, unexpected and critical complications can develop in cases of IgG4-related hepatic IPT.

Diagnosis of autoimmune pancreatitis

Autoimmune pancreatitis (AIP) is a distinct form of chronic pancreatitis that is increasingly being reported. The presentation and clinical image findings of AIP sometimes resemble those of several pancreatic malignancies, but the therapeutic strategy differs appreciably. Therefore, accurate diagnosis is necessary for cases of AIP. To date, AIP is classified into two distinct subtypes from the viewpoints of etiology, serum markers, histology, other organ involvements, and frequency of relapse: type 1 is related to IgG4 (lymphoplasmacytic sclerosing pancreatitis) and type 2 is related to a granulocytic epithelial lesion (idiopathic duct-centric chronic pancreatitis). Both types of AIP are characterized by focal or diffuse pancreatic enlargement accompanied with a narrowing of the main pancreatic duct, and both show dramatic responses to corticosteroid. Unlike type 2, type 1 is characteristically associated with increasing levels of serum IgG4 and positive serum autoantibodies, abundant infiltration of IgG4-positive plasmacytes, frequent extrapancreatic lesions, and relapse. These findings have led several countries to propose diagnostic criteria for AIP, which consist of essentially similar diagnostic items; however, several differences exist for each country, mainly due to differences in the definition of AIP and the modalities used to diagnose this disease. An attempt to unite the diagnostic criteria worldwide was made with the publication in 2011 of the international consensus diagnostic criteria for AIP, established at the 2010 Congress of the International Association of Pancreatology (IAP).

Determination of steroid response by abdominal ultrasound in cases with autoimmune pancreatitis

BACKGROUND

Abdominal ultrasound is the most convenient modality for examining the morphology of the pancreas without physical stress. Steroid response is one of the key features of autoimmune pancreatitis; however, visualizing this response has not been evaluated using ultrasonography.

METHODS

Thirty-three consecutive autoimmune pancreatitis cases were retrospectively investigated for pancreatic and extrapancreatic lesions by ultrasonography before steroid therapy (n=33) and at two weeks (n=28) and one month (n=19) after starting oral steroid treatment.

RESULTS

Steroid treatment resulted in obvious shrinkage of the pancreatic lesion in 86% of the cases at two weeks and in 97% until one month. The maximum thickness of the pancreatic lesion was reduced from 28 to 22 mm in two weeks (P<0.0001), and pancreatic echographic findings improved in one month. Swelling of the peripancreatic lymph node was recognized in 48% and the aortic wall thickness in 12%, mostly reduced in two weeks (P=0.005). One case of definitive autoimmune pancreatitis revealed a steroid response only by following endoscopic retrograde cholangiopancreatography but not by ultrasonography or computed tomography.

CONCLUSIONS

Abdominal ultrasound revealed a steroid response in most cases of autoimmune pancreatitis within two weeks. Ultrasonography is suitable for initial confirmation of a steroid response; however, atypical cases showing insufficient response or not fulfilling criteria should undergo further examination.

Factors affecting the yield of endoscopic transpapillary bile duct biopsy for the diagnosis of pancreatic head cancer

BACKGROUND

Transpapillary biliary biopsy (TBB) is a simple endoscopic technique that can be performed during an initial biliary drainage session. This procedure has the potential to reduce the load of another tissue sampling in cases of pancreatic head cancer (PHC) with biliary stricture. The aim of this study is to identify factors associated with a positive outcome using TBB for PHC.

METHODS

In total, 130 cases that underwent TBB for investigation of distal biliary stricture were included [62 cases of PHC, 36 cases of distal biliary cancer (DBC), and 32 cases of benign biliary stricture (BBS)]. Factors affecting the diagnostic efficiency of TBB were determined using univariate and multivariate logistic analyses.

RESULTS

Cancer tissue was obtained in 31 cases (50%) of PHC and 33 cases (91.7%) of DBC. Multivariable analysis showed that ≧10 mg/dl of serum bilirubin level (odds ratio [OR]: 5.58; 95% confidence interval [CI]: 1.29-28.20; P = 0.021) and ≧3 tissue samplings (OR: 3.59; 95% CI: 1.02-14.27, P = 0.046) were independent factors affecting cancer-positive rate in cases of PHC. In >90% of resected cases of PHC, cancer involved the left side of the biliary mucosa and the range of cancer invasion (≧2/3 of circumference of biliary mucosa) was also a significant factor (P = 0.001).

CONCLUSIONS

PHC showing high level of serum bilirubin (>10 mg/dl) and high circumferential proportion of bile duct invasion (>2/3 judging from MDCT) is a good indication for biliary biopsy. Targeting the left-side wall and ≧3 tissue samplings will lead to the higher sensitivity.

Characteristics of autoimmune pancreatitis based on serum IgG4 level

BACKGROUND

Autoimmune pancreatitis is categorized as an IgG4-related autoimmune disease, mostly associated with serological alterations, however characteristics of autoimmune pancreatitis based on serum markers have not been fully evaluated.

METHODS

We evaluated demographics, symptoms, imaging and therapeutic outcome in 27 cases of autoimmune pancreatitis stratified by serum IgG4 level.

RESULTS

Twenty patients (74%) had elevated serum IgG4 and 7 (26%) had normal IgG4 levels. Compared to patients with normal serum IgG4 levels, patients with elevated IgG4 had higher incidence of jaundice at onset (14.3% vs. 80%, respectively; P=0.002), more frequent diffuse pancreatic enlargement at imaging (14.3% vs. 60%, respectively; P=0.04), significantly higher 18F-2-fluoro-2-deoxy-d-glucose uptake of pancreatic lesions (SUV max: 4.0 vs. 5.7, respectively; P=0.02), more frequent extrapancreatic lesions (42.9% vs. 85%, respectively; P=0.03). Response to steroids was recognized regardless of serum IgG4 level, however maintenance therapy was required more frequently amongst patients with elevated compared to normal IgG4 (85.7% vs. 33.3%, respectively; P=0.04).

CONCLUSIONS

Clinical features of autoimmune pancreatitis are different based on level of serum IgG4. Further studies are needed to clarify if normal serum IgG4 cases are a precursor of active type 1 or type 2 autoimmune pancreatitis.

Usefulness of positron emission tomography in the evaluation of distribution and activity of systemic lesions associated with autoimmune pancreatitis

BACKGROUND/AIMS

Autoimmune pancreatitis (AIP) is an IgG4-related systemic disease often accompanied with a variety of lesions outside of the pancreas and is treated with steroid therapy. The aim of this study is to analyze the usefulness of positron emission tomography with (18)F-fluorodeoxyglucose (FDG-PET) in the evaluation of distribution and activity of systemic lesions of AIP during steroid therapy.

METHODS

Eleven cases of AIP had their FDG-PET images evaluated before and 3 months after steroid therapy and another 2 cases only before therapy. AIP activity was determined by the level of serum markers, IgG and IgG4, and compared with findings of PET.

RESULTS

In all 13 cases of AIP, a moderate to intense level of FDG accumulation was recognized in the pancreatic lesion before steroid therapy. Of 13 patients, 11 (84.6%) showed FDG accumulation in the multiple organs, such as mediastinal and other lymph nodes, salivary gland, biliary tract, prostate, and aortic wall. In 11 patients who underwent PET before and after steroid therapy, FDG accumulation was diminished in almost all systemic lesions, with a mean of maximum standardized uptake value (SUV(max)) in the pancreatic lesion from 5.12 to 2.69. Similar to the SUV level, serum IgG and IgG4 were decreased in most of the cases after steroid therapy.

CONCLUSIONS

FDG-PET is an effective modality to evaluate the response of steroid therapy and the distribution and activity of various systemic lesions of AIP.

Autoimmune pancreatitis without a response to steroid therapy: a case which met criteria after withdrawal of steroid

Autoimmune pancreatitis (AIP) sometimes forms a pancreatic mass lesion, which is often difficult to distinguish from pancreatobiliary malignancy, however it generally responds to steroid therapy. A 70-year-old man was referred to our institute with the suspected diagnosis of pancreatic cancer due to a mass lesion detected at the pancreatic head. Various images demonstrated an ill-defined mass at the enlarged pancreatic head with focal narrowing of the main pancreatic duct. Serum antinuclear antibody (ANA) was negative (x40 dilution) on the onset. Forceps biopsy from the narrowed pancreaticobiliary duct and fine-needle aspiration biopsy under endoscopic ultrasonography (EUS-FNAB) ruled out pancreatobiliary malignancy. Steroid therapy was started at 40 mg per day but was not effective according to subsequent image analyses. Repeated EUS-FNA from the pancreatic mass was performed but was again negative for carcinoma. Seven months later, under steroid-off condition, still no response was recognized in the clinical image but the titer of serum ANA was increased to be positive (x80), satisfying the criteria of AIP in Japan (2006). Although very rare, this is a case meeting Japanese criteria of AIP after withdrawal of steroid without response to steroid in the clinical images, suggesting the necessity of careful follow-up.

A case of pancreatic carcinoma with suspected autoimmune pancreatitis

We present a case of pancreatic carcinoma with strongly suspected coexisting autoimmune pancreatitis (AIP). The patient presented with a chief complaint of icterus and weight loss, and was referred to our institution after a pancreatic lesion was found. Blood test showed elevation of serum bilirubin, hepato-biliary enzyme, glucose and tumor markers, and also high levels of serum IgG4 (344 mg/dl, normal 4.8-105 mg/dl) and anti-DNA antibody (14 IU/ml, normal <6.0 IU/ml). Ultrasonography demonstrated an enlarged pancreas with smooth borders and low internal echo density. Enhanced computed tomography (CT) showed a sausage-shaped pancreas without definitive metastasis to the surrounding lymph nodes and liver. Imaging of the pancreatic duct, including endoscopic retrograde pancreatography (ERP) and magnetic resonance cholangiopancreatography (MRCP), showed stenosis of the main pancreatic duct at the pancreatic head as well as a long segment of narrowing at the body and no dilatation at the tail. Tissues from these stenotic sites and open biopsy from pancreatic body showed infiltrating adenocarcinoma and dense fibrosis. To date, only a small number of reports have described pancreatic carcinoma accompanied with AIP. It is important to confirm diagnosis with histology in cases of suspicious autoimmune pancreatitis, even when the clinical images are compatible with AIP.