Autoimmune pancreatitis type-1 associated with intraduct papillary mucinous neoplasm: report of two cases

Association of autoimmune pancreatitis and intraductal papillary mucinous neoplasm. A retrospective analysis from a tertiary care referral center

BACKGROUND

Autoimmune Pancreatitis (AIP) is a rare chronic inflammatory disease affecting the pancreas. Chronic pancreatic inflammation represents a risk factor for pre-neoplastic conditions such as Intraductal Papillary Mucinous Neoplasia (IPMN). Due to the rarity of AIP, the incidence, and clinical features of IPMN occurring in AIP patients remains unknown.

AIMS

In the present study we aimed to explore the relationship between AIP and IPMN and to characterize the clinical features and outcomes of IPMN occurring in the context of AIP.

METHODS

We retrospectively (2008-2020) analyzed the clinical and radiological records of a large single center cohort of patients with AIP and investigated the prevalence of IPMN. We then compared the clinical, laboratory and radiological characteristics of patients with IPMN and AIP with a cohort of patients with isolated IPMN.

RESULTS

Five hundred and nineteen patients were included in this retrospective study. Sixteen patients had concomitant IPMN and AIP(3%); 61 patients had isolated AIP (12%); 442 patients had isolated IPMN (85%). The prevalence of IPMN in patients with AIP was higher than that observed in the general population (21%vs8-10%). Worrisome Features and High-Risk Stigmata were more frequently observed in IPMN occurring together with AIP compared to isolated IPMN(p < 0.05). Based on radiological features IPMN in the context of AIP was more frequently of main-duct type compared to isolated IPMN(p < 0.05).

CONCLUSION

Our data suggest that AIP represents a chronic inflammatory condition that might favor IPMN development with high-risk features. Prolonged surveillance of these patients and longitudinal studies are required to further test the association with AIP and malignant and pre-malignant conditions.

The Natural Course of Pancreatic Cysts in Inflammatory Bowel Disease: Results of a Long-term Follow-up

OBJECTIVES

The natural course of pancreatic cysts in inflammatory bowel disease (IBD) is unknown. We aim to describe the natural course of pancreatic cysts in IBD and evaluate long-term outcomes.

METHODS

A database of patients with abdominal imaging diagnosis of pancreatic cysts (2008-2019) was reviewed. Patients with IBD and pancreatic cysts (study group) and pancreatic cysts without IBD (controls) were selected. Outcomes were measured at 1, 3, 5, and 10 years. Several logistic regression models were used for analysis.

RESULTS

Of the 1789 patients evaluated, 1690 had pancreatic cysts without IBD, and 78 had IBD and pancreatic cysts. Majority of cysts were intraductal papillary mucinous neoplasms. Patients with IBD and pancreatic cysts were more likely to be diagnosed with pancreatic cysts at a younger age (P < 0.001) and were more likely to undergo surgical intervention at a younger age (P < 0.001).

CONCLUSIONS

This is the first study to evaluate the natural course of pancreatic cysts in IBD patients. Patients with IBD were more likely to have pancreatic cysts detected at a younger age. Despite the early presentation, there were no differences in long-term outcomes. Patients with IBD with pancreatic cysts should be managed similarly to those without IBD.

Histological features of autoimmune pancreatitis and IgG4-related sclerosing cholangitis with a correlation with imaging findings

Autoimmune pancreatitis (AIP) is characterized by a tumefactive inflammatory lesion resembling pancreatic carcinoma. Type 1 AIP is a pancreatic manifestation of IgG4-related disease characterized by unique histological features that can be identified on imaging. The capsule-like rim, which is a collar of hypertrophic lesion surrounding the pancreas, consists of lymphoplasmacytic infiltration and fibrosis, and storiform fibrosis is often identified. Hypertrophic lesions of various microscopic architectures such as the ducts, veins (obliterative phlebitis), arteries (periarteritis), and nerves are observed without parenchymal damage. The pancreatic lobules keep their contours, but the acinar cells are diminished and replaced by numerous inflammatory cells. These features provide clues to arrive at a diagnosis of type 1 AIP and to distinguish it from pancreatic carcinoma on imaging. In contrast, type 2 AIP is an epithelium-centered inflammation involving the ducts and lobules. Neutrophilic infiltration in the epithelium and/or lumens (granulocytic epithelial lesion) is a characteristic finding. Lobular swelling due to inflammation is the cause of pancreatic enlargement. IgG4-related sclerosing cholangitis is histologically similar to the hypertrophic ductal lesion in type 1 AIP and characterized by wall thickening due to inflammation and luminal stenosis. The epithelium is intact, which is different from bile duct carcinomas and primary sclerosing cholangitis, the latter of which is characterized by inflammation targeting the epithelium. Although the histological features of type 1 AIP and IgG4-related sclerosing cholangitis are unique, the biopsy diagnosis of these diseases has limitations, which should be recognized by clinicians.

Rare coincidence of intraductal papillary mucinous neoplasm and type 1 autoimmune pancreatitis

The present case involved a 60-year-old man with autoimmune pancreatitis (AIP). While his AIP was in remission for 6 years, a follow-up CE-CT revealed a dilated main pancreatic duct (MPD) and an enhanced mural nodule. Fluorodeoxyglucose uptake was positive on positron emission tomography. Endoscopic retrograde pancreatography showed a filling defect of the MPD, and pancreatoscopy revealed a nodule partially covered with papillary lesions. Although a repeat biopsy revealed no evidence of malignancy, we speculated that there was a high likelihood of main-duct-type intraductal papillary mucinous neoplasm (IPMN)-derived carcinoma concomitant with AIP. Subsequently, the patient underwent subtotal stomach-preserving pancreaticoduodenectomy. A surgical specimen showed a 35 mm protuberant papillary lesion with abundant stroma, located in the main duct of the pancreas. Further histological evaluation revealed that the nodule was predominantly composed of IPMN with low-grade dysplasia, which was accompanied by abundant IgG4-positive lymphoplasmacytic infiltration, and fibrosis existed predominantly around the IPMN. The epithelium of the cyst showed mucinous hyperplasia with focal papillary structures of gastric phenotype (MUC5A+, MUC6+, MUC1-, MUC2-, CDX-). After surgical resection, we did not find any imaging evidence suggesting a recurrent tumor and AIP relapse in the remnant pancreas. In conclusion, we report a case of IPMN coincidentally found in a patient with type 1 AIP. Active AIP may exaggerate the morphology of IPMN, and careful evaluation should be performed to select appropriate management.

Coexisting Mucinous Cystic Neoplasm of the Pancreas and Type 1 Autoimmune Pancreatitis

Type 1 autoimmune pancreatitis (AIP1) is an IgG4-related systemic disease that mimics tumors. We report a rare case of AIP1 accompanied by mucinous cystic neoplasm (MCN). A pancreatic lesion was incidentally detected in a woman in her 60s. After 6 years of follow-up, the lesion abruptly increased in size. Computed tomography showed a 3.5 cm unilocular cyst in the tail of the pancreas and distal pancreatectomy was performed. On microscopic examination, the cyst was lined by mucinous and non-mucinous epithelial cells with mild cytologic atypia. The surrounding stroma comprised ovarian-type spindle cells with progesterone receptor positivity. The pericystic pancreas exhibited multifocal lymphoid follicles, lymphoplasmacytic infiltrations, obliterative phlebitis, and storiform fibrosis. IgG4-positive plasma cell infiltration (215 cells high-power field) and the IgG4/IgG ratio (57%) were increased. Cases of MCN coexisting with AIP1 are extremely rare; only two such cases have been reported in the English-language literature. This third case featured low-grade MCN with AIP1.

Association of IgG4 response and autoimmune pancreatitis with intraductal papillary-mucinous neoplasms

OBJECTIVES

Concurrent intraductal papillary-mucinous neoplasm (IPMN) and autoimmune pancreatitis (AIP) was observed in a patient (index case) at our institution. Cases of coincidental IPMN and type 1 AIP and concurrent ductal adenocarcinoma (PDAC) and AIP have been previously reported. In this study we evaluate the hypothesis that IPMN elicits an IgG4 response.

METHODS

Twenty-one pancreases (including the index case) with IPMN resected at our institution were studied. H&E stained slides were reviewed and blocks of peritumoral pancreas were immunostained with IgG4 to look for IgG4-positive plasma cells.

RESULTS

We found evidence of variable IgG4 overexpression in 4/21 (19%) of IPMN. These included the index case and three others without stigmata of AIP.

CONCLUSION

A small subset of pancreatic neoplasms including intraductal papillary-mucinous neoplasms (IPMN) is associated with an IgG4 autoimmune response that sometimes progresses to peritumoral type 1 AIP and less often to diffuse AIP and IgG4-related systemic disease.

Intraductal Papillary Neoplasm of the Bile Duct With Invasive Adenocarcinoma Complicating IgG4-related Sclerosing Cholangitis: Report of a Case

Although there have been many previous studies of IgG4-related SC focusing on the differential diagnosis from cholangiocarcinoma, only a few patients with cholangiocarcinoma against a background of IgG4-related SC have been reported. We herein present a case of intraductal papillary neoplasm of the bile duct (IPNB) associated with invasive carcinoma complicating IgG4-related sclerosing cholangitis. A 71-year-old female with icterus was admitted to a local hospital, where stricture of the extrahepatic bile duct were detected, and subsequently referred to our hospital for possible surgery. Abdominal multidetector-row computed tomography demonstrated marked wall thickening along the entire extrahepatic bile duct. The left lateral superior bile duct (B2) and left lateral inferior duct (B3) were individually obstructed, and percutaneous transhepatic biliary drainage catheters were placed in B2 and B3 separately. The patient was diagnosed to have diffusely spread cholangiocarcinoma and underwent right hepatic trisectionectomy with caudate lobectomy and pancreatoduodenectomy. A histological examination revealed intraductal papillary tumors composed of fibrovascular stalks covered by neoplastic epithelium. Carcinomatous invasion of the papillary tumors was observed in the fibromuscular layer, and there was abundant infiltration of inflammatory cells with fibrosis outside of the cancerous tissue. The inflammatory cells were primarily composed of plasma cells, a majority of which were positive for IgG4 (&gt;30 cells/high-power field); the postoperative serum IgG4 level was 890 mg/dL. Therefore, a diagnosis of coexisting IPNB associated with invasive carcinoma and IgG4-related sclerosing cholangitis was made. To the best of our knowledge, this is the first report of IPNB complicating IgG4-related sclerosing cholangitis.

Diagnosis, treatment and long-term outcomes of autoimmune pancreatitis in Spain based on the International Consensus Diagnostic Criteria: A multi-centre study

OBJECTIVES

Autoimmune pancreatitis (AIP) is a form of chronic pancreatitis that has been reported worldwide for the last two decades. The aim of this study is to analyse the clinical profile of patients from Spain with AIP, as well as treatments, relapses and long-term outcomes.

METHODS

Data from 59 patients with suspected AIP that had been diagnosed in 15 institutions are retrospectively analysed. Subjects are classified according to the International Consensus Diagnostic Criteria (ICDC). Patients with type 1 AIP (AIP1) and type 2 AIP (AIP2) are compared. Kaplan-Meier methodology is used to estimate the overall survival without relapses.

RESULTS

Fifty-two patients met ICDC, 45 patients were AIP1 (86.5%). Common manifestations included abdominal pain (65.4%) and obstructive jaundice (51.9%). Diffuse enlargement of pancreas was present in 51.0%; other organ involvement was present in 61.5%. Serum IgG4 increased in 76.7% of AIP1 patients vs. 20.0% in AIP2 (p = 0.028). Tissue specimens were obtained in 76.9%. Initial successful treatment with steroids or surgery was achieved in 79.8% and 17.3%, respectively. Maintenance treatment was given in 59.6%. Relapses were present in 40.4% of AIP1, with a median of 483 days. Successful long-term remission was achieved in 86.4%.

CONCLUSIONS

AIP1 is the most frequent form of AIP in Spain in our dataset. Regularly, ICDC allows AIP diagnosis without the need for surgery. Steroid and chirurgic treatments were effective and safe in most patients with AIP, although maintenance was required many times because of their tendency to relapse. Long-term serious consequences were uncommon.

Intraductal papillary mucinous neoplasm of the pancreas, one manifestation of a more systemic disease?

BACKGROUND

Several studies have demonstrated a high prevalence of extrapancreatic malignancies, and an association with autoimmune pancreatitis in patients with intraductal papillary mucinous neoplasm (IPMN). We hypothesized that IPMNs were associated with an increase rate of systemic diseases.

METHODS

From 1996 to 2013, a retrospective analysis of a prospectively collected database was performed and supplemented with electronic medical charts review.

RESULTS

Two hundred twenty extrapancreatic malignancies were found in 185 patients (22%) compared with expected 5% in the general population. Colorectal, lung, and renal cell carcinoma had significant observed/expected ratios (P < .0001). One hundred ten synchronous autoimmune diseases were found in 96 patients (11%). Systemic lupus erythematosus, rheumatoid arthritis, and inflammatory bowel disease showed statistically significant observed/expected ratios (P < .0001, .01, and <.0001, respectively). There was no impact of immunosuppressive treatment on the IPMN subtype and malignancy rate.

CONCLUSIONS

IPMN are associated with surprisingly high rates of autoimmune diseases suggesting that IPMN might be 1 manifestation of a more systemic disease.