Periductal Lymphoplasmacytic Infiltration Research Articles

Granulocytic epithelial lesion (GEL) in heterotopic pancreas

BackgroundThe diagnosis of type 2 autoimmune pancreatitis (AIP) is dependent on typical radiologic imaging and the presence of the granulocytic epithelial lesion (GEL), which is characterized by ductal neutrophilic infiltration with or without neutrophilic acinar infiltration. MethodsWe evaluated GEL and related clinicopathologic factors in 165 resected heterotopic pancreata (HPs) [57 gastric (35%), 56 duodenal (34%), 30 omental (18%), and 22 jejunal (13%)] and 29 matched orthotopic pancreata routinely examined during surgery. ResultsGEL was noted in 8% (13/165) of HPs, including ductal epithelial (6/13, 46%) and intraluminal (8/13, 62%) neutrophilic infiltrations. However, there was no GEL in orthotopic pancreata. Abdominal pain was observed in 6 (46%) patients with GEL-positive HPs. GEL was more commonly observed in HPs having symptoms (p = 0.029), a larger size (p = 0.028), and an infiltrative growth pattern (p = 0.006). In addition, periductal lymphoplasmacytic infiltration and fibrosis (both p < 0.001), interstitial fibrosis (p = 0.017), acinar neutrophilic infiltration (p = 0.032), venulitis (p = 0.050), acinar ductal metaplasia (ADM; p = 0.040), and pancreatic intraepithelial neoplasia/intraductal papillary mucinous neoplasms (PanIN/IPMN; p < 0.001) were more commonly seen in HPs with GEL than in those without GEL. Inflammatory bowel disease was present only in one patient with GEL-negative HP. ConclusionsGELs are detected in a subset of HPs without clinical evidence of AIP. Therefore, for the diagnosis of AIP, GEL should be carefully interpreted with the context of other histologic, clinical, and radiologic findings.

The role of EUS-guided fine needle aspiration in autoimmune pancreatitis: a single center prospective study

Objectives: Histopathological examination is pivotal in diagnosing autoimmune pancreatitis (AIP). The usefulness of EUS-guided fine needle aspiration (EUS-FNA) in diagnosing AIP remains controversial worldwide. The authors conducted this study to evaluate the efficacy of EUS-FNA for AIP diagnosis using a 22-gauge needle.Methods: Between January 2013 and May 2017, 37 patients had imaging studies suggestive of AIP at Tongji Hospital, and 27 patients of them were enrolled in this study. Tissue specimens acquired through EUS-FNA were analyzed for periductal lymphoplasmacytic infiltrate (LPI), storiform fibrosis (SF), obliterative phlebitis (OP) and immunoglobulin G4 (IgG4)-positive plasma cell counts. Clinical Trials.gov no: TJ-C20121220.Results: LPI and SF were present in 18 (66.67%) and 18 (66.67%) of 27 patients, respectively. Abundant IgG4-positive plasmacyte infiltration >10/high-power field (HPF) was detected in 8 of 27 patients (29.63%). OP and the characteristic findings of idiopathic duct-centric chronic pancreatitis (IDCP) and granulocytic epithelial lesion (GEL) were not detected in this study. According to the International Consensus Diagnostic Criteria (ICDC) for AIP, 5 and 12 of 27 patients were assessed as having level 1 and level 2 histological findings, respectively, suggesting that 17 of 27 patients (62.96%) had lymphoplasmacytic sclerosing pancreatitis (LPSP) based on the ICDC.Conclusions: In 92.6% of patients, pancreatic tissues with >5 HPFs were obtained by EUS-FNA using a 22-G needle. In 63% of patients, histology was evaluated to be ≥ level 2 according to the ICDC. The study indicates that EUS-FNA with a 22-G needle is valuable in the histopathological diagnosis of AIP.

Diagnosis of Autoimmune Pancreatitis: The Evolution of Diagnostic Criteria for a Rare Disease

Diagnosis of Autoimmune Pancreatitis: The Evolution of Diagnostic Criteria for a Rare Disease

Application and Validation of a New Histologic Staging and Grading System for Primary Biliary Cirrhosis

We proposed a new grading and staging system for primary biliary cirrhosis (PBC), which takes into account the degree of both chronic cholangitis activity (CA) and hepatitic activity (HA) for grading disease activity and that of fibrosis, bile duct loss, and chronic cholestasis for staging. In this study, we validated our new system. Using liver biopsy specimens from 166 cases of PBC, chronic cholangitis with mild periductal lymphoplasmacytic infiltration, including chronic nonsuppurative destructive cholangitis, and the combined activity of interface hepatitis and lobular hepatitis were categorized into 4 grades on the basis of their degree and distribution (CA0-3 and HA0-3, respectively). For staging, because orcein staining was not available in this study, 2 criteria (fibrosis and bile duct loss) were independently scored from 0 to 3 on the basis of their degrees, and a final stage score was created from the sum. Although there was a relatively uniform distribution of CA0/1/2/3 cases, the cases of HA0/1/2/3 were distributed as 21%, 64%, 13%, and 3%, respectively, with a prominent number of cases categorized as having none or mild HA. The distribution of stages 1 to 4 using our system was considerably different from that using the classic system and, importantly, showed a correlation with patient outcome. Our system revealed that the activities of chronic cholangitis and hepatitis did not correlate with each other in terms of degree and that our staging system properly reflected the outcome of PBC patients. The present study could validate the effectiveness of this new system for characterizing the pathologic condition of PBC.

Les deux formes de la pancréatite auto-immune

Autoimmune pancreatitis (AIP) is a rare disease (less than 5% of all chronic pancreatitis). AIP concept was first described 20 years ago but usual diagnostic criteria were published in 2006 (HISORt criteria). Since 2 years, a new AIP concept was described distinghing two AIP types because of differences between Asian and Western series. This new classification is based on pathological features. AIP type 1 is a systemic IgG4-related disease, defined by periductal lymphoplasmacytic infiltrate with obliterative phlebitis and storiform fibrosis and/or lymphoplasmacytic infiltrate with abundant IgG4 positive-plasma cells at immunostaining. AIP type 1 fits the classic description of the disease reported in Asian series. It appears to be a pancreatic manifestation of an IgG4-associated systemic disease which could affect numerous organs with abundant infiltration of IgG4 positive-plasma cells (biliary tree, salivary glands, lymph nodes, retroperitoneum, kidney…), associated with elevated IgG4 serum levels. AIP type 2 is characterized by the presence of granulocyte epithelial lesion on pathological examination. The inflammatory infiltrate is usually devoid of IgG4 positive-plasma cells and the IgG4 serum levels are normal. AIP type 2 represents the main pattern in Western series. No association with extra-pancreatic involvement has been described, except for inflammatory bowel disease (IBD) in 20-30% of the cases. AIP diagnosis is based on association of clinical, biological and morphological features. MRI is essential to argue for AIP diagnosis. The consensual treatment is a steroid therapy (4 weeks) according to symptoms and relapses.

Autoimmune Pancreatitis (AIP) Type 1 and Type 2

To develop and validate histologic diagnostic criteria for autoimmune pancreatitis (AIP) and its types. Thirteen pathologists participated in this 2-phase study to develop diagnostic criteria for AIP types 1 and 2 (phase 1) and validate them (phase 2). A virtual library of 40 resected pancreata with AIP and other forms of chronic pancreatitis (CP) was constructed. Readers reviewed the slides online and filled out a questionnaire for histopathologic findings and diagnosis. Diagnostic criteria for AIP and its types were proposed according to the results from the top 5 reviewers in phase 1. The interobserver agreement was significantly improved in phase 2 by applying the proposed diagnostic criteria. Features distinguishing AIP from alcoholic and obstructive forms of CP were periductal lymphoplasmacytic infiltrate, inflamed cellular stroma with storiform fibrosis, obliterative phlebitis, and granulocytic epithelial lesions. Although there was overlap, 2 types of AIP were recognized. Type 1 had dense lymphoplasmacytic infiltrate with storiform fibrosis and obliterative phlebitis, whereas type 2 was distinguished from type 1 by the presence of granulocytic epithelial lesions. Autoimmune pancreatitis can be distinguished from other forms of CP with substantial interobserver agreement. The 2 types of AIP can be distinguished by the proposed consensus histopathologic diagnostic criteria.

Current Concepts in the Diagnosis and Treatment of Type 1 and Type 2 Autoimmune Pancreatitis

Since the 1990s, autoimmune pancreatitis (AIP) has been increasingly recognized as a special type of chronic pancreatitis. Clinically, AIP patients commonly present with jaundice, weight loss and abdominal pain. Radiologically, there is diffuse or focal enlargement of the pancreas, often with narrowing of the pancreas and bile duct. Histologically, AIP is characterized by periductal infiltrates of lymphocytes and plasma cells, cellular fibrosis and obliterative phlebitis. Recently, two types of AIP were distinguished and called type 1 and type 2 AIP. They share the symptomatology and some histopathological features such as periductal lymphoplasmacytic infiltrate and storiform fibrosis, but differ in a particular duct change, called granulocytic epithelial lesion, which characterizes type 2 AIP. In addition, type 2 AIP usually has none or very few (<10 cells/ high power field (hpf)) IgG4-positive plasma cells. Clinically, type 1 AIP patients are roughly 10 years older than type 2 AIP patients, show a slight preponderance of men and reveal extrapancreatic manifestations of IgG4 associated systemic disease in approximately 50% of the cases. Type 2 AIP patients frequently show an association with inflammatory bowel disease and usually lack serological elevation of IgG4. The main differential diagnosis of AIP is pancreatic ductal adenocarcinoma. In many instances the diagnosis of AIP can be made by imaging together with serological markers. In difficult cases, particularly in type 2 AIP, the diagnosis has to be established by core needle biopsy. Both type 1 and type 2 AIP patients respond to steroid treatment, but a significant proportion of type 1 AIP patients suffer from recurrence of the disease. We describe the clinical and histological features of the two types of AIP as well as the treatment. In connection with pathogenesis and diagnosis, recent findings on immune complex deposition, autoantibodies in AIP and relevant patents are discussed.

Autoimmune pancreatitis characterized by predominant CD8+ T lymphocyte infiltration

Autoimmune pancreatitis (AIP) is a rare form of pancreatitis characterized by prominent lymphocyte infiltration and pancreatic fibrosis resulting in organ dysfunction. The pathogenesis and pathology of AIP remain unknown. A 64-year-old Chinese man presented with symptoms and signs of bile duct obstruction diffuse enlargement of the head of pancreas, elevated IgG levels, and negative autoimmune antibody responses. A pylorus-preserving pancreatoduodenectomy was performed and a pancreatic tumor was suspected. However, periductal lymphoplasmacytic infiltration and fibrosis were found in the head of pancreas and nearby organs instead of tumor cells. Four months after surgery, the patient was readmitted because of reoccurrence of severe jaundice and sustained abdominal distension. Prednisone 30 mg/d was administered orally as an AIP was suspected. One and a half months later, the symptoms of the patient disappeared, and globulin, aminotransferase and bilirubin levels decreased significantly. Over a 9-mo follow-up period, the dose of prednisone was gradually decreased to 10 mg/d and the patient remained in good condition. We further demonstrated dominant CD3+/CD8+ populations, CD20+ cells and a few CD4+ cells in the pancreatic parenchyma, duodenum and gallbladder wall by immunohistochemical assay. This AIP case presented with significant CD8+ T lymphocyte infiltration in the pancreas and extra-pancreatic lesions, indicating that this cell population may be more important in mediating AIP pathogenesis than previously known and that AIP might be a poorly defined autoimmune disease with heterogeneous pathogenesis.

Histopathologic and Clinical Subtypes of Autoimmune Pancreatitis

Autoimmune pancreatitis (AIP) has been extensively reported from Japan, Europe, and the United States. Whereas the descriptions of AIP from Japan have predominantly been based on the presence of a distinct clinical phenotype, reports from Europe and the United States describe at least 2 histopathologic patterns in patients' condition currently diagnosed as AIP, viz, lymphoplasmacytic sclerosing pancreatitis (LPSP) and idiopathic duct centric pancreatitis (IDCP) or granulocyte epithelial lesion (GEL)-positive pancreatitis. Although the 2 entities share common histopathologic features (periductal lymphoplasmacytic infiltration and peculiar periductal fibrosis), expert pathologists can accurately distinguish them based on other unique histopathologic features. Clinically, the 2 entities have similar clinical presentation (obstructive jaundice/pancreatic mass and a dramatic response to steroids) but differ significantly in their demography, serological characteristics, other organ involvement, and disease relapse. While LPSP is associated with elevation in titers of nonspecific autoantibodies and serum IgG4 levels, IDCP does not have definitive serological autoimmune markers. All experts agreed that the clinical phenotypes associated with LPSP and IDCP should be nosologically distinguished; however, their terminology was debated. Whereas most experts agreed that the entities should be referred to as type 1 and type 2 AIP, respectively, others had concerns regarding use of the term "autoimmune" to describe IDCP.

Autoimmune pancreatitis: the clinicopathological characteristics of the subtype with granulocytic epithelial lesions

Autoimmune pancreatitis (AIP) has been established as a distinct form of chronic pancreatitis that is distinguishable from other types such as alcoholic, hereditary or obstructive chronic pancreatitis. AIP seems to be a global disease, since it has been reported in many different countries, especially from Japan, USA and Europe (Germany, Italy, United Kingdom). Typical histopathological findings in the pancreas in AIP include a periductal lymphoplasmacytic infiltration with fibrosis, causing narrowing of the involved ducts. The typical clinical features include presentation with obstructive jaundice/pancreatic mass and a dramatic response to steroids. However, while the reports from Japan describe uniform changes called lymphoplasmacytic sclerosing pancreatitis (LPSP) in the pancreas from AIP patients, the reports from Europe and USA distinguish two histopathologic patterns in AIP patients: one with the characteristics of LPSP and another with slightly different histological features, called idiopathic duct centric pancreatitis (IDCP) or AIP with granulocytic epithelial lesions (GELs). This article reviews the evidence that GEL-positive AIP or IDCP is a second type of AIP, distinct from LPSP, in regard to pancreatic pathology, immunology and epidemiology.

IgG4+ Plasma Cell Infiltrates in Liver Explants With Primary Sclerosing Cholangitis

Sclerosing cholangitis can be primary (PSC) or secondary. One unusual cause of secondary sclerosing cholangitis is the newly recognized entity of IgG4-associated cholangitis. The prevalence and significance of IgG4 plasma cells in patients, who are clinically and radiologically classified as PSC, however, are unknown. Clinical information and histology of liver explants of 98 consecutive liver transplants performed for PSC were reviewed. IgG4 immunohistochemical stain was performed on sections from hilar areas that contained large bile ducts and corresponding cholecystectomy specimens (available in 74 cases). Serum IgG4 levels were measured in stored serum from 81 cases. Tissue IgG4 positivity (>or=10 IgG4+ plasma cells/high power field) was correlated with clinical features (age, sex, presence of inflammatory bowel disease and cholangiocarcinoma, pancreatogram, PSC duration, PSC recurrence after transplant, and number of acute rejection episodes) and histologic findings (periductal lymphoplasmacytic infiltrate, storiform fibrosis, and obliterative phlebitis) in the liver explants. Twenty-three (23%) liver explants showed periductal infiltration with IgG4+ plasma cells. Eighteen cases (22%) had elevated serum IgG4 levels, including 8 without tissue IgG4 positivity. All cases showed dense periductal fibrosis; none had storiform fibrosis or obliterative phlebitis. IgG4 positivity in the liver strongly correlated with moderate-to-marked periductal lymphoplasmacytic inflammation (P=0.002). Clinically, IgG4 positivity in tissue, but not in serum, was correlated with shorter PSC duration before transplant and higher risk of recurrence after transplant. Nearly one quarter of explanted livers that carry a clinical diagnosis of PSC contain increased IgG4+ periductal plasma cell infiltrates and positive serum IgG4 levels. However, none of the explants show histologic features diagnostic of IgG4-associated cholangitis. PSC with tissue IgG4 positivity has a more aggressive clinical course manifested by shorter time to transplant and a higher likelihood of recurrence than IgG4 negative PSC.

LYMPHOPLASMACYTIC SCLEROSING PANCREATITIS (LPSP) AND IDIOPATHIC DUCT CENTRIC PANCREATIS (IDCP) ARE DISTINCT CLINICAL FORMS OF AUTOIMMUNE PANCREATITIS (AIP)

Background: Two distinct histological patterns, viz., LPSP and IDCP, are seen in AIP (Am J Surg Path 2003:27;1119-27). Methods: We compared the profiles of histologically confirmed LPSP (n = 28) (Features: periductal lympho-plasmacytic infiltrate, storiform fibrosis and obliterative phlebitis without granulocyte epithelial lesions (GELs) and IDCP (n = 13) (Features: prominent neutrophilic infiltrate in the lobule and duct (GELs) with duct destruction.) Results: While LPSP subjects presented more often with obstructive jaundice (25/28 vs 4/13, p < 0.05), IDCP subjects were more likely to be evaluated for pancreatic duct stricture without a mass (3/13 vs 0/28, p < 0.05). LPSP patients were a decade older than IDCP subjects (mean age 61.2 ± 12.4 vs 50.4 ± 19.1, p < 0.05); the proportion of men in both groups was similar (79% vs 69%). Serum IgG4 was elevated in 9/12 LPSP vs 0/2 IDCP. Involvement of proximal bile duct, retroperitoneum, salivary glands or kidney was seen in LPSP but not IDCP (11/28 vs 0/13, p < 0.05). 2 IDCP and 1 LPSP patient had inflammatory bowel disease. All 7 LPSP patients receiving steroids responded; IDCP did not receive steroids as all were diagnosed after resection. Conclusion: LPSP and IDCP appear to be distinct clinical entities for which we propose the terms type I and type II AIP, respectively. IDCP cannot be diagnosed prospectively by current diagnostic criteria as it is not associated serum IgG4 elevation, or other organ involvement.

Atteinte biliaire au cours d’une pancréatite auto-immune : quel cadre nosologique et quel traitement ?

Autoimmune pancreatitis is a rare disease characterized by inflammation of the pancreatic parenchyma, irregular narrowing of the pancreatic duct, periductal lymphoplasmacytic infiltration and fibrosis at histological examination, the presence of autoantibodies and hypergammaglobulinemia, as well as the possible association of cholangitis and other autoimmune diseases. There is a favorable response to steroid therapy. We report the case of a patient with autoimmune pancreatitis with bile duct involvement and peripheral eosinophilia, requiring long-term immunosuppressant treatment. The diagnosis of a diffuse form of AIP was made without direct histological evidence and based on indirect imaging, clinical and laboratory findings in an autoimmune context. The histological and imaging studies of bile duct involvement and the favourable response to steroids were additional arguments.

Korea-Japan Symposium for Autoimmune Pancreatitis

Korea-Japan Symposium for Autoimmune Pancreatitis

Can histopathology be the “Gold Standard” for diagnosing autoimmune pancreatitis?

Can histopathology be the “Gold Standard” for diagnosing autoimmune pancreatitis?

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

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. 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. 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. 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.

RELAPSING AUTOIMMUNE PANCREATITIS PRESENTING AS A LARGE PERIPANCREATIC MASS WITH SEROCONVERSION OF IgG4 LEVELS

Introduction: Autoimmune pancreatitis (AIP) is characterized by diffuse pancreatic enlargement, main duct abnormalities, elevated serum gamma-globulins or IgG levels, autoantibodies, other autoimmune diseases (Sjo-gren's syndrome, primary sclerosing cholangitis), a periductal lymphoplas-macytic infiltrate, and responsiveness to corticosteroids. We describe a patient with AIP presenting with a large distal peripancreatic mass that relapsed after steroid withdrawal, developing IgG4 antibodies during relapse, though seronegative at presentation. Case: A 65-year-old Caucasian male presented with bloating and painless jaundice. CT and MRI revealed diffuse pancreatic enlargement with a distal mass. EUS-guided biopsies revealed chronically inflamed pancreatic parenchyma. Repeated ERCPs showed evanescent strictures in the distal common bile duct, hilum and pancreatic duct, with negative brushings. Tumor markers, gammaglobulins and autoimmune serologies were unremarkable. Prednisone was started for presumed autoimmune cholangiopancreati-tis, with marked clinical and radiographic improvement. Six months after steroid cessation, the patient had bloating and weight loss. Repeat imaging revealed a large hypodense peripancreatic soft tissue mass with vascular encasement, biopsies again revealing chronic inflammation and fibrosis, with new elevation of serum IgG4. He was restarted on prednisone, with dramatic mass reduction after 6 weeks, at which time azathioprine was initiated to allow a steroid taper. Discussion: The presentation of AIP with obstructive jaundice, weight loss, new-onset diabetes and pancreatic mass in the elderly male often mimics that of pancreatic adenocarcinoma. In reports from Japan, AIP is almost universally associated with autoantibodies (antinuclear antibody, rheumatoid factor, antilactoferrin antibody or anticarbonic anhydrase II antibody), with majority having hypergammaglobulinemia and isolated IgG4 elevation. In the West, seropositivity is less well described. Diabetes mellitus is present in 50%, which may improve after AIP treatment. CT or MRI shows a characteristic capsule-like rim around the inflammation, surrounding the pancreatic head in 80%, with calcifications or pseudocysts rarely seen. Patients typically have a prompt response to steroids, but treatment length, utility of other immunosuppressants and prognosis are not well known.

Idiopathic chronic pancreatitis with periductal lymphoplasmacytic infiltration: clinicopathologic features of 35 cases.

To clarify clinicopathologic features of idiopathic chronic pancreatitis with lymphoplasmacytic infiltration, we carried out a study of 35 cases. There were two histologic groups, which we have designated lymphoplasmacytic sclerosing pancreatitis and idiopathic duct-centric chronic pancreatitis. Lymphoplasmacytic sclerosing pancreatitis (22 cases) was a fibrosing process with diffuse lymphoplasmacytic infiltrates involving pancreatic lobules and ducts, adipose tissue, blood vessels, and common bile duct. Obliterative phlebitis was found in every case except for one. The histologic features were similar to other idiopathic fibrosclerosing disorders, and one patient also had retroperitoneal fibrosis. Affected patients tended to be elderly men. Idiopathic duct-centric chronic pancreatitis (13 cases) was characterized by inflammatory infiltrates (including neutrophils) that were denser in the lobules than in interlobular fibrotic areas. Neutrophils were also prominent in the ducts, and destruction of the duct epithelium was commonly seen. Patient ages were more broadly distributed than in lymphoplasmacytic sclerosing pancreatitis. Two patients had inflammatory bowel disease. We conclude that idiopathic chronic pancreatitis with lymphoplasmacytic infiltration, sometimes called autoimmune pancreatitis, consists of at least two different processes. One of these, lymphoplasmacytic sclerosing pancreatitis, is a histologically unique lesion and could be a pancreatic manifestation of idiopathic fibrosclerosing disorders.

Idiopathic tumefactive chronic pancreatitis: Clinical profile, histology, and natural history after resection

Background & Aims: Little is known about subjects with idiopathic tumefactive chronic pancreatitis (TCP), that is, chronic pancreatitis whose clinical presentation, usually with a mass or obstructive jaundice, suggests cancer. Methods: We independently reviewed clinical data and histology of 45 TCP (27 idiopathic, 18 alcohol induced) resected at Mayo Clinic (January 1985-March 2001). Follow-up data were obtained from medical records and mailed questionnaires. Results: Compared with alcoholic subjects, idiopathic TCP patients were older (58 ± 2 vs. 48 ± 3 yr, P < 0.001), had shorter symptom duration (median 3 vs. 24 wk, P < 0.001), were more likely to have no or mild abdominal pain (70% vs. 17%, P = 0.001), and were more often jaundiced (67% vs. 33%, P = 0.02). Three distinct histologic patterns were identified in TCP. Typical CP (n = 19) showed lobular atrophy, fat necrosis, and ductal changes (dilatation, protein plugs, and stones). Lymphoplasmacytic sclerosing pancreatitis (LPSP) (n = 14) was characterized by periductal lymphoplasmacytic infiltration, obliterative phlebitis, and cholangitis with edema. Idiopathic duct-centric CP (IDCP) (n = 12) had neutrophil-predominant lobular inflammation, without phlebitis. On correlation of clinical and histologic diagnosis, 17 of 18 (94%) patients with alcohol-induced TCP had typical CP, and 25 of 27 (93%) with idiopathic TCP had LPSP or IDCP. LPSP and IDCP were indistinguishable clinically except for higher incidence of jaundice in LPSP (93% vs. 42%, P = 0.005). In idiopathic TCP no recurrence of symptoms was observed after resection (median follow-up 49 mo). Conclusions: Idiopathic TCP is clinically and histologically distinct from alcohol-induced TCP. It is unclear whether LPSP and IDCP, 2 unique patterns of histologic injury observed in idiopathic TCP, are part of the spectrum of the same disease or represent 2 or more different entities. Resection of mass prevents recurrence of symptoms in idiopathic TCP.