Is pancreatic core biopsy sufficient to diagnose autoimmune chronic pancreatitis?

The role of Movat pentachrome stain and immunoglobulin G4 immunostaining in the diagnosis of autoimmune pancreatitis

Autoimmune pancreatitis is highly responsive to steroid therapy, but because it mimics pancreatic cancer, it often precipitates unnecessary surgery. Adequate diagnostic tests are needed to permit appropriate medical therapy. Lymphocytic and obliterative phlebitis are reported in the majority of cases, as are elevated IgG4-positive plasma cells, indicating their high sensitivity. Their specificities, especially when used in conjunction, however, remain largely unknown. Movat pentachrome vascular and IgG4 immunohistochemical stains were performed on a total of 15 autoimmune pancreatitis cases (11 pancreatic resections and 4 biopsies), 39 usual-type alcoholic or idiopathic chronic pancreatitis cases, 35 pancreatic ductal adenocarcinoma-associated chronic pancreatitis cases, and 29 normal pancreata. Marked and diffuse lymphocytic and obliterative venulitis were detected in all 15 cases of autoimmune pancreatitis on Movat staining (100% sensitivity). Only a single carcinoma-associated chronic pancreatitis case among all of the controls showed diffuse benign venulitis that was nonobliterative (99% specificity). Nine of 13, 9 autoimmune pancreatitis cases showed marked IgG4 immunopositivity at >or=10 positive plasma cells per x 400 field (69% sensitivity). No increased IgG4 plasma cells were found in any of 103 controls (100% specificity). In combination, all of the autoimmune pancreatitis cases had at least one (13/13) and most had both markers (9/13), whereas none of the controls had both markers. Overall, these combined stains show very promising diagnostic utility and should be considered in combination with clinical and serologic analyses in the evaluation of chronic pancreatitis suspicious for malignancy. Future validating studies on preoperative biopsies with outcome data following steroid therapy will be essential.

Diagnosis of autoimmune pancreatitis by core needle biopsy: application of six microscopic criteria

Autoimmune pancreatitis (AIP) has been established as a special entity of chronic pancreatitis (CP). However, its clinical distinction from pancreatic cancer and other types of CP is still difficult. The aim of this study was to evaluate the efficacy of pancreatic core needle biopsy for the diagnosis of AIP. In 44 core needle biopsy specimens, we assessed the following microscopic features: granulocytic epithelial lesions (GELs), more than ten IgG4-positive plasma cells/HPF, more than ten eosinophilic granulocytes/HPF, cellular fibrosis with inflammation, lymphoplasmacytic infiltration, and venulitis. All biopsies that showed four or more of the six features (22 of 44) were obtained from 21 of 26 patients whose clinical diagnosis and follow-up were consistent with AIP. All non-AIP CP patients (n = 14) showed three or less than three of the features in their biopsies. GELs were only observed in biopsy specimens from AIP patients. In conclusion, our data indicate that the six criteria we applied were able to recognize AIP in 76% of biopsy specimens using a cut-off level of four. When the specimens that revealed only three features but showed GELs were added, the sensitivity rose to 86%. Pancreatic core needle biopsy can therefore make a significant contribution to the diagnosis of AIP.

Preoperative tissue diagnosis for tumours of the pancreas

BACKGROUND

Preoperative biopsy of pancreatic lesions suspected of malignancy is controversial.

METHODS

A systematic Medline literature search was carried out. Diagnostic studies reporting quantitative preoperative pancreatic biopsy data were evaluated.

RESULTS

The analysis included 53 studies, mostly of a retrospective nature. Despite acceptable rates for sensitivity and specificity, the negative predictive value of percutaneous and endoscopic ultrasonography-guided biopsies was 60-70 per cent. Biopsy results were considered to be essential for directing non-surgical therapy in advanced disease. However, they were of limited value in planning the treatment of resectable solid or cystic tumours, or focal lesions in the setting of chronic pancreatitis.

CONCLUSIONS

Biopsy of suspected pancreatic malignancies with systemic spread or local irresectability is indicated for planning palliative or neoadjuvant therapy. Preoperative biopsy of potentially resectable pancreatic tumours is not generally advisable, as malignancy cannot be ruled out with adequate reliability.

Review of 67 patients with autoimmune pancreatitis in Korea: a multicenter nationwide study

OBJECTIVES

The ideal diagnostic criteria of autoimmune pancreatitis (AIP) are still challenging. Therefore, we investigated the clinical features of AIP in Korea and assessed the clinical use of new Korean diagnostic criteria.

METHODS

We reviewed 67 patients with AIP enrolled in 16 hospitals via a multicenter study. The diagnosis was confirmed according to the Korean diagnostic criteria that included pancreatic imaging, laboratory findings, histopathology, and response to steroid.

RESULTS

Mean age of the patients was 56 years, and 73% were men. Obstructive jaundice (52%) was the most common symptom, and 14 patients (21%) had other organ involvement. Fifty-four patients (81%) revealed diffuse swelling of the pancreas. Either immunoglobulin (Ig)G or IgG4 was elevated in 76%. According to the Korean criteria, 65 patients had definite diagnostic criteria, and 2 patients had probable criteria. Fifteen patients were fulfilled with image, serological, and histopathologic criteria, and 4 patients could be diagnosed with image and steroid responsiveness. Ten patients experienced recurrent attacks of AIP during the mean 20-month follow-up.

CONCLUSIONS

Among 67 cases of AIP, either IgG or IgG4 was elevated in 76% of patients, and 14 patients (21%) had other organ involvement. New Korean diagnostic criteria are useful for diagnosis of AIP.

Asian diagnostic criteria for autoimmune pancreatitis: consensus of the Japan-Korea Symposium on Autoimmune Pancreatitis

In 2002, the Japan Pancreas Society (JPS) was the first in the world to propose diagnostic criteria for autoimmune pancreatitis (AIP). Since the concept of AIP has changed with the accumulation of AIP cases, the Research Committee of Intractable Pancreatic Diseases (RCIPD) provided by the Ministry of Health, Labour and Welfare of Japan and the JPS issued revised clinical diagnostic criteria of AIP in 2006. The Asan Medical Center of Korea also proposed diagnostic criteria for AIP in 2006. However, there are subtle but clinically challenging differences between the Japanese and Korean criteria. This inconsistency makes it difficult to compare data in studies from different centers and elucidate the characteristics of AIP. To reach a consensus on AIP, the RCIPD and the Korean Society of Pancreatobiliary Diseases established the following Asian criteria for the diagnosis of AIP: I-1. Imaging studies of pancreatic parenchyma show a diffuse/segmental/focally enlarged gland, occasionally with a mass and/or a hypoattenuation rim. I-2. Imaging studies of pancreaticobiliary ducts show diffuse/segmental/focal pancreatic ductal narrowing, often with stenosis of the bile duct. (Both I-1 and I-2 are required for diagnosis). II. Elevated level of serum IgG or IgG4, and detection of autoantibodies. III. Common lymphoplasmacytic infiltration and fibrosis, with abundant IgG4-positive cell infiltration. AIP should be diagnosed when criterion I and one of the other two criteria are satisfied, or when histology shows the presence of lymphoplasmacytic sclerosing pancreatitis in the resected pancreas. A diagnostic trial of steroid therapy can be applied carefully by expert pancreatologists only in patients fulfilling criterion I alone with negative diagnostic work-up results for pancreatobiliary cancer.

Autoimmune pancreatitis

PURPOSE OF REVIEW

Autoimmune pancreatitis (AIP) is an increasingly recognized clinical condition. Our objective is to provide a concise review of the advances in the past year in our understanding of AIP.

RECENT FINDINGS

In a hospital survey from Japan, the prevalence of AIP was estimated at 0.82 per 100,000 individuals. The pathogenesis of AIP remains unclear but a recent report noted that T helper type 2 and T regulatory cells predominantly mediate the immune reaction in AIP. Genetic associations that may predispose to relapse of AIP were reported. Multiple case series further described the clinical profile of AIP and its extrapancreatic manifestations. A large series on immunoglobulin G4 (IgG4)-associated cholangitis noted that patients with IgG4-associated cholangitis presented with obstructive jaundice and had increased serum IgG4 levels and IgG4-positive cells in bile duct biopsy specimens. Tissue IgG4 staining is likely to be a useful adjunct to serological diagnosis. AIP is steroid-responsive but maintaining remission continues to remain challenging. Presently low-dose steroids or immunomodulators are being used but efficacy of these medications remains to be determined.

SUMMARY

There has been significant progress in understanding the clinical profile of AIP but knowledge of pathogenesis remains limited. Treatment practices vary widely and management of refractory disease continues to be challenging.

Autoimmune pancreatitis: an adolescent case and review of literature

We present a case of a 16-year-old adolescent boy with autoimmune pancreatitis and a review of the related literature. The patient was sent from a peripheral medical center, presenting with jaundice, pruritus, weight loss, and hyperglycemia of 20 days' duration. At admission, the patient was icteric, choluric, and acholic. His abdomen was soft and nontender, and the patient felt no pain in his abdomen. He had skin lesions because of scratching. Laboratory findings showed a blood glucose level of 135 mg%; total serum bilirubin, 29.4 mg%; direct bilirubin, 23 mg%; and alkaline phosphatase, 1100 IU/L. Abdominal ultrasound showed an enlarged head of the pancreas that was 30 x 35 mm. The parenchyma was slightly heterogeneous. Abdominal computed tomography showed an enlarged head of the pancreas with a normal body and tail, thickened duodenal wall, and dilated intra- and extrahepatic biliary tract, and the distal choledochus was not visible. Magnetic resonance imaging showed dilated intra- and extrahepatic biliary tract. The choledochus was not visible, and the cystic duct ended abruptly. The pancreas head was enlarged and homogenous, and there were no changes with contrast. Wirsung's duct was not dilated. Laparotomy was performed with a presumed diagnosis of pancreatic head tumor. The pancreas was diffusely indurated and enlarged; biopsy and intraoperative cholangiography were performed. The biliary tract was dilated with no duodenal passage of contrast, and the Wirsung's duct was not observed. Cholecystectomy was performed, and a transcystic drain was positioned. The histopathology was compatible with autoimmune pancreatitis. Prednisone treatment was started with good response. Autoimmune pancreatitis is a very rare entity among children and adolescents. It should be suspected when characteristic clinical signs and radiographic images are associated with a higher level of IgG4. Autoimmune pancreatitis is confirmed by biopsy. Treatment with prednisone often alleviates all the symptoms, as what happened in this case.

Early bile duct cancer in a background of sclerosing cholangitis and autoimmune pancreatitis

A 59-year-old man presented with recent onset jaundice. Initial laboratory and radiologic findings suggested autoimmune pancreatitis (AIP) with consequent obstructive jaundice. All serologic markers for AIP were, however, normal. To confirm the histologic finding of AIP and exclude the possibility of cancer at the thickened segment of common bile duct, cholangioscopic examination was performed and bile duct cancer was observed. The resected specimen showed typical features of AIP throughout the entire pancreas and early carcinomatous change on a background of abundant IgG4-positive cells in the common bile duct. Although chronic biliary inflammation and cholestasis are among bile duct cancer risk factors, the cause-and-effect relationship between sclerosing cholangitis and bile duct cancer needs to be determined by further study, as between AIP and pancreatic cancer. Importantly, histologic exclusion of malignancy is another essential step in the diagnosis of AIP and sclerosing cholangitis as malignancy may coexist in bile duct as well as in the pancreas.