Pancreatic cystic lesions with atypical steroid response should be carefully managed in cases of autoimmune pancreatitis

Pancreatico-renal fistula associated with pancreatic cysts caused by type 1 autoimmune pancreatitis

To our best knowledge, the formation of a pancreatico-renal fistula and the presence of pancreatic fluid collection in the renal subcapsular space have not been reported as autoimmune pancreatitis (AIP) complications. We describe a case of a pancreatico-renal fistula associated with type 1 AIP. The patient presented with abdominal and back pain accompanied by pancreatic cystic lesions during an untreated course of AIP. The diagnosis of pancreatico-renal fistula was based on the presence of a left renal subcapsular fluid collection containing pancreatic amylase, disappearance of pancreatic cysts, and a defect in the partial anterior renal fascia observed on imaging studies. Treatment with steroids and percutaneous drainage resulted in improvement. Pancreatic pseudocysts can affect other organs owing to their digestive action. Similar symptoms may occur in patients with AIP.

Auto-immune pancreatitis with unusual presentations - A case series

Auto-immune pancreatitis (AIP) is a rare benign disease commonly presented with painless obstructive jaundice and biliary obstruction with rare complications like pseudocyst. We present a case series of two patients of AIP with unusual presentations; one case presented with periorbital swelling, jaundice, and pseudocyst, and the other case presented with abdominal pain and biliary obstruction without jaundice; both showed good response with steroids.

Steroid therapy has an acceptable role as the initial treatment in autoimmune pancreatitis patients with pancreatic cyst formation: Based on a Japanese nationwide study

BACKGROUND

We attempted to determine the indications and limitations of steroid therapy as the first-line therapy in patients with autoimmune pancreatitis (AIP) with cyst formation (ACF).

METHODS

This Japanese multicenter survey was conducted to examine the merits/demerits of steroid treatment as the initial therapy for ACF.

RESULTS

Data of a total of 115 patients with ACF were analyzed. Complete remission was achieved in 86% (86/100) of patients who had received steroid treatment, but only 33.3% (5/15) of patients who had not received steroids. Relapse after the remission (n = 86) occurred in 7.6% (6/86) of patients who had received steroid therapy, but 40% (2/5) of patients who had not received steroid therapy. Multivariate analysis identified adoption of the wait and watch approach without steroid treatment (odds ratio = 0.126, P < .001) as a significant and independent negative predictor of remission of ACF. As for predictors of relapse, the presence of varix (odds ratio = 5.83, P = .036) was identified as an independent risk factor.

CONCLUSION

Steroid therapy plays an important role as first-line therapy in AIP patients with pancreatic cyst formation, however, varix formation, besides the diameter of the cyst(s), is a risk factor for refractoriness to steroid therapy.

Pancreatic cancer in patients with autoimmune pancreatitis: A scoping review

BACKGROUND

Chronic pancreatitis is a known risk factor of pancreatic cancer (PDAC). A similar association has been suggested but not demonstrated for autoimmune pancreatitis (AIP).

OBJECTIVE

The aim of our study was to identify and analyse all published cases of AIP and PDAC co-occurrence, focusing on the interval between the diagnoses and the cancer site within the pancreas.

METHODS

Relevant studies were identified through automatic searches of the MEDLINE, EMBASE, Scopus, and Web of Science databases, and supplemented by manual checks of reference lists in all retrieved articles. Missing/unpublished data were obtained from the authors of relevant publications in the form of pre-prepared questionnaires.

RESULTS

A total of 45 cases of PDAC in AIP patients were identified, of which 12 were excluded from the analysis due to suspicions of duplicity or lack of sufficient data. Thirty-one patients (94%) had type 1 AIP. Synchronous occurrence of PDAC and AIP was reported in 11 patients (33%), metachronous in 22 patients (67%). In the metachronous group, the median period between diagnoses was 66.5 months (2-186) and a majority of cancers (86%) occurred more than two years after AIP diagnosis. In most patients (70%), the cancer originated in the part of the pancreas affected by AIP.

CONCLUSIONS

In the literature, there are reports on numerous cases of PDAC in AIP patients. PDAC is more frequent in AIP type 1 patients, typically metachronous in character, and generally found in the part of the pancreas affected by AIP.

A resected case of focal autoimmune pancreatitis with pancreatic duct wall thickening representing periductal lymphoplasmacytic infiltrate

This case revealed that branch pancreatic duct wall thickening by endoscopic ultrasonography represented periductal lymphoplasmacytic infiltrate as a characteristic histopathological finding of autoimmune pancreatitis, which may help in the diagnosis of autoimmune pancreatitis. An 80-year-old man was referred because fluorodeoxyglucose-positron emission tomography for lung cancer indicated abnormal uptake in the pancreatic head. Computed tomography showed an enhanced mass with cystic structures in the pancreatic head. Magnetic resonance cholangiopancreatography revealed mild dilatation of the main pancreatic duct in the pancreatic body with no strictures. Endoscopic ultrasonography demonstrated a lobulated heterogeneous hypoechoic mass in the pancreatic head. A branch pancreatic duct with wall thickening connected the mass to the main pancreatic duct. An intraductal neoplasm filling and spreading into the branch pancreatic duct was considered, and surgery was performed. Histopathologically, the mass consisted of marked inflammatory cell infiltration, storiform fibrosis, and obliterative phlebitis. The branch pancreatic duct with wall thickening revealed a band-like inflammatory cell infiltration with mainly lymphocytes and plasma cells beneath the normal pancreatic duct epithelium. Immunohistological staining revealed abundant IgG4-positive plasma cells (> 10 cells/HPF) in the inflammatory cell infiltration. The definite diagnosis was type 1 focal autoimmune pancreatitis.

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.

Type 1 Autoimmune Pancreatitis Extending along the Main Pancreatic Duct: IgG4-related Pancreatic Periductitis

We herein report a unique form of autoimmune pancreatitis (AIP) spreading along the main pancreatic duct (MPD). A 70-year-old man was referred for a small lesion at the pancreatic neck, accompanying an adjacent cyst and dilated upstream MPD. Four years earlier, health checkup images had shown a pancreatic cyst but no mass lesion. Endoscopic ultrasonography showed a contrast-enhanced, tumorous lesion, mainly occupying the MPD. With a preoperative diagnosis of ductal neoplasms mainly spreading in the MPD, Whipple's resection was performed. The resected specimens showed MPD periductitis with IgG4-related pathology, indicating type 1 AIP. Clinicians should practice caution concerning the various AIP forms.

Endoscopic ultrasonography-guided drainage for spontaneous rupture of a pancreatic pseudocyst into the peritoneal cavity in a patient with autoimmune pancreatitis

A 75-year-old man was referred to our hospital due to a huge pancreatic cyst. Computed tomography revealed a monocular cyst 15 cm in size without a solid mass lesion nearby. He was diagnosed with pancreatic pseudocyst. Endoscopic ultrasound (EUS)-guided drainage was planned for the next day due to abdominal distension; however, the pseudocyst ruptured into the peritoneal cavity before treatment could be applied. To prevent the progression of peritonitis, EUS-guided drainage of the pseudocyst was performed. A nasocystic tube and plastic stent were placed into the ruptured cyst via the gastric wall through the same puncture tract. After the treatment, the cyst rapidly decreased in size, and the peritonitis improved without surgery. The patient's serum IgG4 level was found to be elevated to 820 mg/dL. Endoscopic retrograde cholangiopancreatography revealed main pancreatic duct stricture without obstruction. No communication between the main pancreatic duct and the pseudocyst was found. An EUS-guided fine-needle aspiration biopsy of the hypoechoic site was performed, revealing IgG4-positive plasma cell infiltration. He was finally diagnosed with AIP associated with the rupture of a pseudocyst. Oral corticosteroid (30 mg/day) treatment was started and gradually tapered. There has been no recurrence in the 28 months since the initiation of treatment.

Multilocular Cyst of Type 1 Autoimmune Pancreatitis Masquerading as Cancerization of Intraductal Papillary Mucinous Neoplasm

A small proportion of intraductal papillary mucinous neoplasms (IPMNs) are accompanied by type 1 autoimmune pancreatitis (AIP); however their clinical courses and image characteristics have not been fully reported. A 65-year-old woman was referred to our hospital for the examination of a pancreatic head cyst that had shown exacerbation for two years. Several images demonstrated a multilocular cyst with a symmetrically thickened, enhanced, cyst wall. Cancerization of IPMN was suspected, and pancreatoduodenectomy was performed. The resected specimens showed a multilocular cyst with solid areas. The solid areas demonstrated pathological findings that corresponded with type 1 AIP. Papillary epithelia suggestive of IPMN was recognized in some parts of the cystic wall.

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.

Elevating pancreatic cystic lesion stratification: Current and future pancreatic cancer biomarker(s)

Pancreatic ductal adenocarcinoma (PDAC) is an incredibly deadly disease with a 5-year survival rate of 9%. The presence of pancreatic cystic lesions (PCLs) confers an increased likelihood of future pancreatic cancer in patients placing them in a high-risk category. Discerning concurrent malignancy and risk of future PCL progression to cancer must be carefully and accurately determined to improve survival outcomes and avoid unnecessary morbidity of pancreatic resection. Unfortunately, current image-based guidelines are inadequate to distinguish benign from malignant lesions. There continues to be a need for accurate molecular and imaging biomarker(s) capable of identifying malignant PCLs and predicting the malignant potential of PCLs to enable risk stratification and effective intervention management. This review provides an update on the current status of biomarkers from pancreatic cystic fluid, pancreatic juice, and seromic molecular analyses and discusses the potential of radiomics for differentiating PCLs harboring cancer from those that do not.

Type 1 Autoimmune Pancreatitis with Imaging Appearance Similar to That of Malignant Cystic Tumor

A 79-year-old man was admitted with asymptomatic elevation of liver enzymes and tumor markers. Abdominal contrast-enhanced computed tomography demonstrated swelling of the pancreatic head, and additional blood test showed raised IgG4 levels. Histological examination by endoscopic ultrasonography (EUS)-guided fine needle aspiration for pancreatic head mass revealed storiform fibrosis and IgG4-positive plasma cell infiltration. We diagnosed this case as type 1 autoimmune pancreatitis (AIP). In addition, there was a cystic lesion in the pancreatic body apart from the pancreatic head mass. A mural nodule in the multilocular cyst was detected by EUS, and there was positive uptake of fluorodeoxyglucose in positron emission tomography/magnetic resonance imaging. The preoperative diagnosis of this cystic lesion was intraductal papillary mucinous carcinoma, and distal pancreatomy was performed. Histopathological findings showed various sizes of retention cysts caused by IgG4-positive plasma cell infiltration around the pancreatic branch ducts. The mural nodule was a fibrotic mass with diffuse infiltration of IgG4-positive cells. This cystic lesion mimicking malignant cystic neoplasm occurred in relation to AIP. This case provided important information helping to understand the mechanism of formation of mural nodules in multilocular cysts in patients with type 1 AIP.

Effectiveness of steroid therapy for pancreatic cysts complicating autoimmune pancreatitis and management strategy for cyst-related complications

Objectives: Autoimmune pancreatitis (AIP) sometimes becomes complicated with pancreatic cysts, although their detailed characteristics and management strategy have not been fully determined. We aimed to clarify the efficiency of steroid therapy and the risk factors for cyst formation and cyst-related complications. Methods: One hundred sixty-three AIP patients were retrospectively analyzed for relevant factors of cyst formation. We compared subjects with and without steroids to evaluate drug effectiveness on cyst size change and investigated the factors associated with cyst-related complications. Results: Thirty-two patients (19.6%) had complicating pancreatic cyst formation, and 40 cystic lesions of ≥10 mm in size were detected. Multivariate analysis revealed a drinking habit, abdominal/back pain, and elevated serum amylase to be significantly associated with cyst formation. Steroid-treated cysts became significantly reduced in size in the short-term and disappeared significantly more frequently within 1-year as compared with non-treated ones, which was confirmed by multivariate analysis. Six of 40 cysts exhibited cyst-related complications significantly associated with multilocular morphology and larger size. Conclusions: Steroid therapy is an effective choice for cysts developing in AIP to promote the release of pancreatic juice stasis. Larger lesions with multilocular morphology should be monitored closely for cyst-related complications and be considered strong candidates for steroid therapy.

The Role of Endoscopic Ultrasound-guided Drainage for Autoimmune Pancreatitis-associated Pancreatic Cysts: A Report of Five Cases and a Literature Review

Objective Autoimmune pancreatitis (AIP) has been recognized as a benign disease, which that shows a prompt response to corticosteroid treatment (CST). It was previously believed to not be associated with cyst formation; however, a few cases of AIP-associated pancreatic cyst (PC) have been reported. Some cases were reported to have been effectively treated by CST, while others were refractory to CST. Many of the patients received interventional treatment. Until now, there has been no consensus on the therapeutic strategies for AIP-associated PC. The aim of the present study is to describe a therapeutic strategy for this condition. Methods We conducted a retrospective study of 5 cases of AIP-associated PC that were treated by endoscopic ultrasonography-guided pancreatic fluid collection drainage (ESPD) or CST at Tokyo Medical University Hospital between March 2012 and October 2016, analyzed the therapeutic outcomes, and performed a literature review. Results The initial treatments included CST (n=2) and ESPD (n=3). All of the PCs disappeared after treatment In 1 of the patients who received CST case and 3 of the patients who received ESPD; however, the PC did not disappear in one of the patients who received CST (corticosteroid maintenance therapy), even after the dose of corticosteroids was increased; ESPD was eventually performed and the PC disappeared. There were no procedure-related complaints. Conclusion We propose that CST be administered as the first-line treatment for AIP-associated PC, particularly in cases of PC without a history of CST. However, ESPD can be applied to treat cases of corticosteroid refractory PC.

Transpapillary biliary stenting is a risk factor for pancreatic stones in patients with autoimmune pancreatitis

BACKGROUND AND STUDY AIM

Pancreatic stones occasionally develop in autoimmune pancreatitis (AIP), often worsen endocrine and exocrine functions, and occasionally cause pain attacks. However, the risks of pancreatic stones in AIP have been poorly studied. The aim of this study was to analyze the risk factors associated with pancreatic stone formation in cases of AIP.

PATIENTS AND METHODS

In total, 50 patients with AIP (39 males, 11 females; mean age 64.0 years), followed up for at least a year, were analyzed for their demographic and clinical findings and pancreatic stone occurrence.

RESULTS

In total, 50 patients were followed up for an average of 59.7 (12 - 120) months, with steroid treatment in 44 patients (88 %); pancreatic stones occurred in 14 (28 %) patients after the diagnosis of AIP and endoscopic treatment was needed in one patient with pain attack. The pancreatic stones appeared only in patients with long follow-up period (P < 0.001, 83.9 months vs. 49.6 months), biliary stenting (odds ratio [OR]: 8.40, P = 0.010), relapse (OR: 6.20, P = 0.023), jaundice (OR: 5.40, P = 0.019), and swelling of the duodenal major papilla (OR: 4.67, P = 0.040). Biliary stenting was placed for an average of 9.9 months in 27 patients. Multivariate analysis revealed a significant association only with biliary stenting (P = 0.011). The stones appeared relatively earlier in patients with stones in the main pancreatic duct or Santorini duct (22.1 months) than in patients where pancreatic stones developed elsewhere (53.4 months) (P = 0.018).

CONCLUSIONS

The risk of pancreatic stone development should be taken into account when a biliary stent is placed in patients with AIP.