Paraduodenal pancreatitis: a clinico-pathologically distinct entity unifying "cystic dystrophy of heterotopic pancreas", "para-duodenal wall cyst", and "groove pancreatitis"

Navigating the Groove: A Unique Case of Groove Pancreatitis

Groove pancreatitis (GP) is an uncommon form of chronic pancreatitis (CP) that affects the area between the duodenum, the head of the pancreas, and the common bile duct (CBD), which is known as the pancreaticoduodenal groove. Our case is based on a 68-year-old male with a past medical history of alcohol use disorder and a 50-pack-year smoking history who presented with nausea, vomiting, and poor oral intake. Computed tomography (CT) of the abdomen and pelvis showed gastric outlet obstruction due to a 6.0 cm mass in the pancreatic groove and the second portion of the duodenum, with dilation of the pancreatic, intrahepatic, and extrahepatic biliary ducts. In order to rule out malignancy and evaluate the acute symptoms, the patient underwent an open pancreaticoduodenectomy (PD). Pathologic findings and negative tumor markers confirmed GP. This case highlights a rare form of CP that symptomatically and radiographically mimics malignancy, but is benign.

Unraveling the Narrow Alley: A Case Report of Groove Pancreatitis

Groove pancreatitis, a rare subtype of chronic pancreatitis, predominantly affects middle-aged men with a history of alcohol abuse. We present a unique case of a 31-year-old female with minimal alcohol consumption. Imaging revealed characteristic findings consistent with groove pancreatitis. Despite its rarity in young females, clinical suspicion led to the appropriate diagnosis and conservative management, resulting in symptomatic resolution. This case underscores the importance of recognizing atypical presentations of groove pancreatitis, emphasizing the necessity of tailored diagnostic approaches, and highlighting the efficacy of conservative management in achieving favorable outcomes, particularly in non-typical demographics.

Autoimmune pancreatitis: Biopsy interpretation and differential diagnosis

Autoimmune pancreatitis (AIP) is classified into type 1 (IgG4-related) and type 2 (IgG4-unrelated) and the interpretation of pancreatic biopsy findings plays a crucial role in their diagnosis. Needle biopsy of type 1 AIP in the acute or subacute phase shows a diffuse lymphoplasmacytic infiltrate, storiform fibrosis, obliterative phlebitis, and the infiltration of many IgG4-positive plasma cells. In a later phase, changes become less inflammatory and more fibrotic, making interpretations more challenging. Confirmation of the lack of 'negative' findings that are unlikely to occur in type 1 AIP (e.g., neutrophilic infiltration, abscess) is important to avoid an overdiagnosis. The number of IgG4-positive plasma cells increases to >10 cells/high-power field (hpf), and the IgG4/IgG-positive plasma cell ratio exceeds 40 %. However, these are minimal criteria and typical cases show >30 positive cells/hpf and a ratio >70 % even in biopsy specimens. Therefore, cases with a borderline increase in this number or ratio need to be diagnosed with caution. In cases of ductal adenocarcinoma, the upstream pancreas rarely shows type 1 AIP-like changes; however, the ratio of IgG4/IgG-positive plasma cells is typically <40 %. Although the identification of a granulocytic epithelial lesion (GEL) is crucial for type 2 AIP, this finding needs to be interpreted in conjunction with a background dense lymphoplasmacytic infiltrate. An isolated neutrophilic duct injury can occur in peritumoral or obstructive pancreatitis. Drug-induced pancreatitis in patients with inflammatory bowel disease often mimics type 2 AIP clinically and pathologically. IL-8 and PD-L1 are potential ancillary immunohistochemical markers for type 2 AIP, requiring validation studies.

Duodenojejunostomy treatment of groove pancreatitis-induced stenosis and obstruction of the horizontal duodenum: A case report

BACKGROUND

Groove pancreatitis (GP) is a rare condition affecting the pancreatic groove region within the dorsal-cranial part of the pancreatic head, duodenum, and common bile duct. As a rare form of chronic pancreatitis, GP poses a diagnostic and therapeutic challenge for clinicians. GP is frequently misdiagnosed or not considered; thus, the diagnosis is often delayed by weeks or months. The treatment of GP is complicated and often requires surgical intervention, especially pancreatoduodenectomy.

CASE SUMMARY

A 66-year-old man with a history of long-term drinking was admitted to the gastroenterology department of our hospital, complaining of vomiting and acid reflux. Upper gastrointestinal endoscopy showed luminal stenosis in the descending part of the duodenum. Abdominal computed tomography showed slight exudation in the descending and horizontal parts of the duodenum with broadening of the groove region, indicating local pancreatitis. The symptoms of intestinal obstruction were not relieved with conservative therapy, and insertion of an enteral feeding tube was not successful. Exploratory laparoscopy was performed and revealed a hard mass with scarring in the horizontal part of the duodenum and stenosis. Intraoperative frozen section analysis showed no evidence of malignancy, and side-to-side duodenojejunostomy was performed. Routine pathologic examination showed massive proliferation of fibrous tissue, hyaline change, and the proliferation of spindle cells. Based on the radiologic and pathologic characteristics, a diagnosis of GP was made. The patient presented with anastomotic obstruction postoperatively and took a long time to recover, requiring supportive therapy.

CONCLUSION

GP often involves the descending and horizontal parts of the duodenum and causes duodenal stenosis, impaired duodenal motility, and gastric emptying due to fibrosis.

Groove Pancreatitis: Clinical Cases and Review of the Literature

Introduction

Groove pancreatitis (GP) is a type of chronic segmental pancreatitis that affects the pancreatoduodenal groove area, and it is often misdiagnosed. Outflow obstruction of the minor papilla associated with alcohol consumption seems to be the main pathophysiological mechanism, and it affects mainly middle-aged males. Symptoms include nausea and postprandial vomiting from gastric outlet obstruction, weight loss, and abdominal pain. Despite modern advances, such as radiological and endoscopic methods, distinction between GP and pancreatic cancer remains a challenge, and histological examination is sometimes necessary. When a diagnosis can be obtained without a surgical specimen, management can be conservative in the absence of acute or chronic complications.

Case Presentation

The authors present 2 clinical cases which portray the diagnostic workup and management decisions of this entity.

Discussion/Conclusion

GP is a clinical entity, offering diagnostic and therapeutic challenges. Imaging exams are crucial in the diagnosis and follow-up, but surgery may be necessary in a significant number of cases due to the incapacity to rule out malignancy.

Pancreatic Cancer and Its Mimics

Pancreatic ductal adenocarcinoma (PDAC) is the most common primary pancreatic malignancy, ranking fourth in cancer-related mortality in the United States. Typically, PDAC appears on images as a hypovascular mass with upstream pancreatic duct dilatation and abrupt duct cutoff, distal pancreatic atrophy, and vascular encasement, with metastatic involvement including lymphadenopathy. However, atypical manifestations that may limit detection of the underlying PDAC may also occur. Atypical PDAC features include findings related to associated conditions such as acute or chronic pancreatitis, a mass that is isointense to the parenchyma, multiplicity, diffuse tumor infiltration, associated calcifications, and cystic components. Several neoplastic and inflammatory conditions can mimic PDAC, such as paraduodenal "groove" pancreatitis, autoimmune pancreatitis, focal acute and chronic pancreatitis, neuroendocrine tumors, solid pseudopapillary neoplasms, metastases, and lymphoma. Differentiation of these conditions from PDAC can be challenging due to overlapping CT and MRI features; however, certain findings can help in differentiation. Diffusion-weighted MRI can be helpful but also can be nonspecific. Accurate diagnosis is pivotal for guiding therapeutic planning and potential outcomes in PDAC and avoiding biopsy or surgical treatment of some of these mimics. Biopsy may still be required for diagnosis in some cases. The authors describe the typical and atypical imaging findings of PDAC and features that may help to differentiate PDAC from its mimics. ©RSNA, 2023 Online supplemental material is available for this article. Quiz questions for this article are available through the Online Learning Center. See the invited commentary by Zins in this issue.

Systematic review on groove pancreatitis: management of a rare disease

BACKGROUND

Groove pancreatitis is a focal form of chronic pancreatitis affecting the area of the paraduodenal groove. The aim of this systematic review was to assess the clinical presentation, diagnosis and treatment of patients with groove pancreatitis.

METHODS

Medical literature databases (Embase, Medline via PubMed and Cochrane Central Register of Controlled Trials) were systematically searched for data recorded between 1 January 1990 and 31 August 2022 regarding patient characteristics, diagnosis, surgical treatment and outcomes. The following inclusion criteria were applied: RCTs, observational studies (cohort and case-control studies) and case studies with >3 cases including patients with groove pancreatitis undergoing medical, endoscopic or surgical treatment with available clinical and diagnostic data. Fisher's exact test for binary data and Mann-Whitney U test or Student t-test for continuous data were adopted for statistical analysis.

RESULTS

Of 649 studies, 44 were included, involving reports on 1404 patients with a mean age of 49 years. In 41 of the 44 studies in which patient gender was described, 86 per cent (N = 1023) of patients were male. Information on the risk factors of alcohol and nicotine was available in 37 and 23 studies, respectively. Seventy-nine per cent (N = 886) of patients had a history of excessive alcohol consumption and 83 per cent (N = 595) were smokers. Information on clinical symptoms was available in 37 of the 44 included studies and 78.5 per cent (N = 870) presented with abdominal pain. Some 27 studies comprising 920 groove pancreatitis patients were treatment oriented. Seventy-four per cent (N = 682) of patients were treated conservatively, 26.4 per cent (N = 134) underwent endoscopic treatment and 54.7 per cent (N = 503) required surgery. There was complete relief of symptoms in 35.6 per cent (N = 243) after conservative treatment, 55.2 per cent (N = 74) after endoscopic treatment and 69.6 per cent (N = 350) after surgical treatment. The median follow-up time was 42 months (range, 1-161 months).

CONCLUSION

Groove pancreatitis shows on imaging a typical triad: cystic lesions in the pancreatic duct or duodenal wall, calcifications, and thickenings of the duodenal wall. Surgery appears to be the most effective treatment modality.

Duodenum-preserving pancreatic head resection or pancreatoduodenectomy for the surgical treatment of paraduodenal pancreatitis: a retrospective cohort study

PURPOSE

Paraduodenal pancreatitis (PDP) is an uncommon yet well-described type of focal chronic pancreatitis. The aim of our study was to compare the outcomes of surgical treatment of patients with PDP using pancreatoduodenectomy and duodenum-preserving pancreatic head resection (DPPHR).

METHODS

A retrospective analysis of 153 consecutive patients with PDP was performed. Patients who were treated with either DPPHR or PD were enrolled. The primary endpoint of the study was pain control achieved at the time of follow-up. The secondary endpoints of the study were complication rate (Clavien-Dindo > 2), hospital length of stay, and 90-day mortality. All patients were followed up after discharge for the assessment of pain cessation for a minimal period of 10 months.

RESULTS

The final study population consisted of 71 patients. A total of 14 patients (19.7%) underwent pancreatoduodenectomy, and 57 (80.3%) were managed with DPPHR. Complication rate was significantly lower in DPPHR group at χ² = 4.2677, p < 0.05. Mean hospital length of stay was 9.3 days (range 3-29) in DPPHR group and 13.9 days (range 7-35) in PD group (p < 0.05). No postoperative mortality was recorded. The mean follow-up period of the patients after surgery was 41.8 ± 20.6 months (range 10-88). Pain scores at the time of operation were calculated as 50.9 ± 12.1 in DPPHR group and 56.1 ± 11.4 in PD group. At the time of follow-up, pain scores improved significantly in both groups and were 10.3 ± 8.8 and 10.9 ± 8.6, respectively.

CONCLUSION

DPPHR achieves similar results in pain control as PD with a lower complication rate and shorter hospital LOS.

Cystic dystrophy in heterotopic pancreas

Cystic dystrophy in heterotopic pancreas, or paraduodenal pancreatitis, is a rare and complicated presentation involving heterotopic pancreatic tissue in the duodenal wall. This condition is present in 5% of the general population but disease mainly affects middle-aged alcoholic-smoking men with chronic pancreatitis (CP). It may be purely duodenal or segmental (pancreatico-duodenopathy). Its pathophysiology arises from alcohol toxicity with obstruction of small ducts of heterotopic pancreatic tissue present in the duodenal wall and the pancreatic-duodenal sulcus, leading to repeated episodes of pancreatitis. The symptomatology includes episodes of acute pancreatitis, weight loss, and vomiting due to duodenal obstruction. Imaging shows thickening of the wall of the second portion of the duodenum with multiple small cysts. A stepwise therapeutic approach is preferred. Conservative medical treatment is favored in first intention (analgesics, continuous enteral feeding, somatostatin analogues), which allows complete symptomatic regression in 57% of cases associated with a 5% rate of complications (arterial thrombosis and diabetes). Endoscopic treatment may also be associated with conservative measures. Surgery achieves a complete regression of symptoms in 79% of cases but with a 20% rate of complications. Surgery is indicated in case of therapeutic failure or in case of doubt about a malignant tumor. Pancreaticoduodenectomy and duodenal resection with pancreatic preservation (PPDR) seem to be the most effective treatments. PPDR has also been proposed as a first-line treatment for purely duodenal location of paraduodenal pancreatitis, thereby preventing progression to an extended segmental form.

Imaging of paraduodenal pancreatitis: A systematic review

BACKGROUND

Paraduodenal pancreatitis (PP) represents a diagnostic challenge, especially in non-referral centers, given its potential imaging overlap with pancreatic cancer. There are two main histological variants of PP, the cystic and the solid, with slightly different imaging appearances. Moreover, imaging findings in PP may change over time because of disease progression and/or as an effect of its risk factors exposition, namely alcohol intake and smoking.

AIM

To describe multimodality imaging findings in patients affected by PP to help clinicians in the differential diagnosis with pancreatic cancer.

METHODS

The systematic review was conducted according to the Preferred Reporting Items for Systematic reviews and Meta-analyses 2009 guidelines. A Literature search was performed on PubMed, Embase and Cochrane Library using (groove pancreatitis [Title/Abstract]) OR (PP [Title/Abstract]) as key words. A total of 593 articles were considered for inclusion. After eliminating duplicates, and title and abstract screening, 53 full-text articles were assessed for eligibility. Eligibility criteria were: Original studies including 8 or more patients, fully written in English, describing imaging findings in PP, with pathological confirmation or clinical-radiological follow-up as the gold standard. Finally, 14 studies were included in our systematic review.

RESULTS

Computed tomography (CT) findings were described in 292 patients, magnetic resonance imaging (MRI) findings in 231 and endoscopic ultrasound (EUS) findings in 115. Duodenal wall thickening was observed in 88.8% of the cases: Detection rate was 96.5% at EUS, 91.0% at MRI and 84.1% at CT. Second duodenal portion increased enhancement was recognizable in 76.3% of the cases: Detection rate was 84.4% at MRI and 72.1% at CT. Cysts within the duodenal wall were detected in 82.6% of the cases: Detection rate was 94.4% at EUS, 81.9% at MRI and 75.7% at CT. A solid mass in the groove region was described in 40.9% of the cases; in 78.3% of the cases, it showed patchy enhancement in the portal venous phase, and in 100% appeared iso/hyperintense during delayed phase imaging. Only 3.6% of the lesions showed restricted diffusion. The prevalence of radiological signs of chronic obstructive pancreatitis, namely main pancreatic duct dilatation, pancreatic calcifications, and pancreatic cysts, was extremely variable in the different articles.

CONCLUSION

PP has peculiar imaging findings. MRI is the best radiological imaging modality for diagnosing PP, but EUS is more accurate than MRI in depicting duodenal wall alterations.

Groove pancreatitis and how to differentiate it from pancreatic adenocarcinoma

Groove pancreatitis is an uncommon type of chronic pancreatitis that affects the space between the head of the pancreas, the second portion of the duodenum, and the common bile duct. The main trigger is chronic alcohol abuse, which eventually leads to leakage of pancreatic juices into the pancreaticoduodenal groove, causing inflammation and fibrosis. The main differential diagnosis is with pancreatic adenocarcinoma, which is more common than groove pancreatitis. Different imaging techniques make it possible to identify various findings (e.g., duodenal thickening or duodenal and paraduodenal cysts, which are characteristic of groove pancreatitis) that sometimes enable differentiation between groove pancreatitis and other entities, although there are no specific findings for each of them. Sometimes biopsy or surgery is required to establish the definitive diagnosis. The treatment of groove pancreatitis is usually conservative, but in cases in which the symptoms do not improve, interventional procedures (biliary drainage) or surgery (Whipple technique) can be done.

A case of groove pancreatitis with duodenal stenosis successfully treated by endoscopic ultrasonography‐guided pancreaticogastrostomy

One of the reasons for groove pancreatitis is caused by the leakage of pancreatic juice into the space between the pancreatic head, descending duodenum, and common bile duct. Endoscopic drainage of Santorini's duct (SD) via the minor papilla is reportedly efficacious but can be difficult due to duodenal stenosis. We report Santorini's duct drainage using endoscopic ultrasonography‐guided pancreaticogastrostomy (EUS‐PGS) for a case of groove pancreatitis with gastric outlet obstruction. Gastric outlet obstruction was improved after 7 months of EUS‐PGS with internal drainage through the Santorini's duct/minor papilla. EUS‐PGS may be effective for treating groove pancreatitis with duodenal stenosis. This is the first report of groove pancreatitis with duodenal stenosis, the symptoms of which were improved by EUS‐PGS.

Acute obstructive suppurative pancreatic ductitis (AOSPD) with duodenal obstruction treated by pancreaticoduodenectomy (PD): a rare case report

We report a rare case of acute obstructive suppurative pancreatic ductitis (AOSPD) accompanied by duodenal obstruction in a patient with chronic pancreatitis (CP). A woman in her 40s was admitted to our hospital for intermittent abdominal distension, epigastric pain, and vomiting, which worsened during the previous 6 months. Gastroscopy showed incomplete pyloric obstruction, and computed tomography (CT) revealed calcification in the enlarged head of the pancreas, dilation of the main pancreatic duct (MPD), and thickening of both the gastric antrum and duodenal walls. The patient was preoperatively diagnosed as having an inflamed head of the pancreas, with a stone, and duodenal obstruction. Pancreaticoduodenectomy (PD) was performed to resolve the duodenal obstruction and remove the pancreatic stone. While transecting the neck of the pancreas, frank pus began to flow from the MPD, and the pus was drained and collected. Bacterial culture of the purulent pancreatic juice revealed the presence of Escherichia coli, confirming AOSPD. The patient’s symptoms were relieved, and she recovered fully, after the surgery. In conclusion, AOSPD associated with duodenal obstruction can be treated successfully by PD.

Outcome of Whipple's procedure for Groove pancreatitis: A retrospective cross-sectional study

Background

Groove pancreatitis (GP) is a rare form of chronic pancreatitis primarily affecting the pancreatoduodenal groove. Very few studies have been published from India. The aim of the present study is to report our experience with Whipple's procedure for GP.

Methodology

In this cross-sectional study, data of all patients who underwent Whipple's procedure for GP between August 2007 and July 2021 were retrospectively reviewed.

Results

Of the total 504 Whipple's procedures, histopathologically proven GP was identified in 9 patients. All of them were male. Mean age at presentation was 42.66 ± 4.35 years. All of them had history of alcohol abuse. Eight (88.8%) of them had history of smoking. Postprandial abdominal discomfort and pain (n = 9, 100%) was the most common presenting symptom. Three (33.3%) patients had solid variety and six (66.6%) patients had cystic dystrophy of the duodenal wall. Two (22.2%) patients had mass in the head of the pancreas which was thought to be malignant. None of the patients underwent prior endoscopic management (stenting). Duration of surgery and blood loss was 330 (range, 300–379) minutes, and 250 (range, 200–750) ml respectively. There was no postoperative mortality. Postoperative complications developed in 5 (55.5%) patients. All the complications were managed conservatively. Median postoperative hospital stay was 10 (range, 9–16) days. Over a median follow-up of 41 (range, 12–120) months, complete remission of symptoms was achieved in 7 (78%) patients.

Conclusion

Whipple's procedure is safe with acceptable perioperative outcomes and good long-term symptom control.

•

Groove pancreatitis (GP) is a rare form of chronic pancreatitis which involves the pancreatoduodenal groove.

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It is difficult to differentiate GP from pancreatic head malignancy preoperatively

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Whipple's procedure in GP has acceptable perioperative morbidity and mortality and long-term good results.

CT imaging patterns of paraduodenal pancreatitis: a unique clinicoradiological entity

AIM

To analyse the computed tomography (CT) findings of paraduodenal pancreatitis (PP) in patients treated at Amrita Institute of Medical Sciences.

MATERIALS AND METHODS

Clinical, laboratory, and CT findings of 30 patients with PP treated from July 2007 to December 2020 were reviewed retrospectively.

RESULTS

The average age of the patients was 45.9 years (19-60 years), which included 29 (96.7%) men, and 90% had a history of alcohol abuse. The majority [22 (73.3%)] presented with recurrent abdominal pain. Serum amylase was elevated in 21 (70%) patients and serum lipase was elevated in 25 (83.3%) patients. Carbohydrate antigen (CA 19-9) was elevated in three (10%) patients. The cystic pattern was seen in three (10%), solid pattern in 13 (43.3%), and solid-cystic pattern in 14 (46.7%) patients. The pure form of the disease was seen in seven (23.3%) patients, whereas the segmental form was seen in 23 (76.7%) patients. Descending duodenal wall thickening and enhancement was seen in 25 (83.3%) and 18 (60%) patients, respectively. The gastroduodenal artery was displaced medially in 12 (40%) patients and encased in five (16.7%) patients; however, it was not occluded in any of the patients. Calcifications were seen in the groove lesion in nine (30%) patients. The pancreas showed atrophic changes in 14 (46.6%) patients and calcifications in 12 (40%) patients. Distal common bile duct strictures were seen in three (10%) patients.

CONCLUSIONS

The presence of sheet-like soft-tissue thickening in the groove with diffuse duodenal thickening and intramural/paraduodenal cysts are highly suggestive of PP. Identifying characteristic imaging findings of PP may help in prospective diagnosis and lead to conservative management of most of these patients avoiding unnecessary invasive procedures.

Paraduodenal pancreatitis - problem in the groove

BACKGROUND

Paraduodenal pancreatitis (PDP) is a particular form of chronic pancreatitis (CP) occurring in and around the duodenal wall. Despite its low prevalence, this rare condition presents a significant challenge in clinical practice.

METHODS

We retrospectively analysed the electronic medical charts of all patients with a diagnosis of chronic pancreatitis and identified those with PDP, between January 1999 and December 2020.

RESULTS

There were 35 patients diagnosed with PDP (86% males and 14% females); median age of 56 ± 11 (range 38-80). Alcohol overconsumption was reported in 81% and smoking in 90% of patients. Abdominal pain was the leading symptom (71%), followed by weight loss, nausea and vomiting, jaundice, and diarrhoea. In 23 patients (66%), recurrent acute pancreatitis attacks were noted. Focal duodenal wall thickening was present in 34 patients (97%), cystic lesions in 80%, pancreatic duct dilatation in 54% and common bile duct dilatation in 46%. Endoscopic treatment was performed on nine patients (26%) and five patients (14%) underwent surgery. Complete symptom relief was reported in 12 patients (34%), partial symptom relief in three (9%), there was no improvement in five (14%), data were not available in three (9%) and 12 (34%) patients died before data analysis.

CONCLUSIONS

PDP is a rare form of pancreatitis, most commonly occurring in the 5th or 6th decade of life, with a predominance in males and patients with a history of smoking and high alcohol consumption. Focal thickening and cystic lesions of the duodenal wall are the most common imaging findings, followed by pancreatic duct and common bile duct dilatation. A minority of patients requires surgery.

Pancreatic ductal adenocarcinomas associated with intraductal papillary mucinous neoplasms (IPMNs) versus pseudo-IPMNs: relative frequency, clinicopathologic characteristics and differential diagnosis

The literature is highly conflicted on what percentage of pancreatic ductal adenocarcinomas (PDACs) arise in association with intraductal papillary mucinous neoplasms (IPMNs). Some studies have claimed that even small (Sendai-negative) IPMNs frequently lead to PDAC. Recently, more refined pathologic definitions for mucin-lined cysts were provided in consensus manuscripts, but so far there is no systematic analysis regarding the frequency and clinicopathologic characteristics of IPMN-mimickers, i.e., pseudo-IPMNs. In this study, as the first step in establishing frequency, we performed a systematic review of the pathologic findings in 501 consecutive ordinary PDACs, which disclosed that 10% of PDACs had associated cysts ≥1 cm. While 31 (6.2%) of these were IPMN or mucinous cystic neoplasm (MCN), 19 (3.8%) were other cyst types that mimicked IPMN (pseudo-IPMNs) per recent WHO/consensus criteria. As the second step of the study, we performed a comparative clinicopathologic analysis by also including our entire surgical pathology/consultation databases that was comprised of 60 IPMN-associated PDACs, 30 MCN-associated PDACs and 40 pseudo-IPMN-associated PDACs. We found that 84% of true IPMNs were pre-operatively recognized, whereas IPMN was considered in differential diagnosis of 33% of pseudo-IPMNs. Of the 40 pseudo-IPMNs, there were 15 secondary duct ectasias; 6 large-duct-type PDACs; 5 pseudocysts; 5 cystic tumor necrosis; 4 simple mucinous cysts; 3 groove pancreatitis-associated paraduodenal wall cysts; and 2 congenital cysts. Microscopically, pseudo-IPMNs had at least partial mucinous-lining mimicking IPMN but had smaller cystic (mean = 1.9 cm) and larger PDAC (mean = 3.8 cm) components compared to true IPMNs (cyst = 5.7 cm; PDAC = 2.0 cm). In summary, in this pathologically verified analysis that utilized refined criteria, 10% of PDACs were discovered to have cysts ≥1 cm, about two-thirds of which were IPMN/MCN but about one-third were pseudo-IPMNs. True IPMNs underlying the PDACs are often large and are already diagnosed pre-operatively as having an IPMN component, whereas only a third of the pseudo-IPMNs receive IPMN diagnosis by imaging and their cysts are smaller. At the histopathologic level, pseudo-IPMNs are highly prone to misdiagnosis as IPMN, which presumably accounts for much higher association of IPMNs with PDAC as reported in some studies. The subtle but salient characteristics of pseudo-IPMNs elucidated in this study should be combined with careful radiological/clinical correlation in order to exclude pseudo-IPMNs.

Insight into gastrointestinal heterotopic pancreas: imaging evaluation and differential diagnosis

Heterotopic pancreas (HP) is an uncommon congenital abnormality in the developmental process of the pancreas, with gastrointestinal heterotopic pancreas (GHP) being the most common HP. The clinical manifestations of GHP may have variable patterns of presentation, dictated by both the anatomic location and the functional ability of the lesion. The most common imaging modality in detecting GHP is computed tomography (CT), while gastrointestinal barium fluoroscopy, endoscopic ultrasonography, and magnetic resonance imaging (MRI) are also applied. The density and enhancement patterns of GHP are consistent with histological classifications. GHP with a predominantly acinar tissue component manifests homogeneous and marked enhancement on CT images, whereas a predominantly ductal GHP presents heterogeneous and mild enhancement. On MRI, the appearance and signal intensity of GHP were paralleled to the normal pancreas on all sequences and were characterized by T1-weighted high signal and early marked enhancement. This article provides a comprehensive review of the histopathology, clinical manifestations, imaging features of various modalities, and differential diagnosis of GHP. It is hoped that this review will improve clinicians' knowledge of GHP and aid in accurate preoperative diagnosis, thereby reducing the misdiagnosis rate.

Surgery for chronic pancreatitis: the comparison of two high-volume centers reveals lack of a uniform operative management

Purpose

Many aspects of surgical therapy for chronic pancreatitis (CP), including the correct indication and timing, as well as the most appropriate operative techniques, are still a matter of debate in the surgical community and vary widely across different centers. The aim of the present study was to uncover and analyze these differences by comparing the experiences of two specialized surgical units in Italy and Austria.

Methods

All patients operated for CP between 2000 and 2018 at the two centers involved were included in this retrospective analysis. Data regarding the clinical history and the pre- and perioperative surgical course were analyzed and compared between the two institutions.

Results

Our analysis showed a progressive decrease in the annual rate of pancreatic surgical procedures performed for CP in Verona (no. = 91) over the last two decades (from 3% to less than 1%); by contrast, this percentage increased from 3 to 9% in Vienna (no. = 77) during the same time frame. Considerable differences were also detected with regard to the timing of surgery from the first diagnosis of CP — 4 years (IQR 5.5) in the Austrian series vs two (IQR 4.0) in the Italian series -, and of indications for surgery, with a 12% higher prevalence of groove pancreatitis among patients in the Verona cohort.

Conclusion

The comparison of the surgical attitude towards CP between two surgical centers proved that a consistent approach to this pathology still is lacking. The identification of common guidelines and labels of surgical eligibility is advisable in order to avoid interinstitutional treatment disparities.

Inflammatory and tumor-like lesions of the pancreas

Inflammatory/tumor-like lesions of the pancreas represent a heterogeneous group of diseases that can variably involve the pancreatic gland determining different signs and symptoms. In the category of inflammatory/tumor-like lesions of the pancreas, the most important entities are represented by chronic pancreatitis, which includes alcoholic, obstructive and hereditary pancreatitis, paraduodenal (groove) pancreatitis, autoimmune pancreatitis, lymphoepithelial cyst, pancreatic hamartoma and intrapancreatic accessory spleen. An in-depth knowledge of such diseases is essential, since they can cause severe morbidity and may represent a potential life-threatening risk for patients. Furthermore, in some cases the differential diagnosis with malignant tumors may be challenging. Herein we provide a general overview of all these categories, with the specific aim of highlighting their most important clinic-pathological hallmarks to be used in routine diagnostic activities and clinical practice.

Diagnosis, natural course and treatment outcomes of groove pancreatitis

BACKGROUND

Groove pancreatitis (GP) is a rare form of chronic pancreatitis with limited data on its diagnostics and treatment outcomes. The aim of this study was to assess its diagnostics, natural course, and treatment options.

METHODS

The study is a retrospective population-based study from Southern Finland, including all patients with suspected GP between January 2005 and December 2015. Two certified gastrointestinal radiologists re-reviewed the imaging studies. The radiological re-review, clinical judgment, and final histopathology confirmed the GP diagnoses.

RESULTS

Out of 67 patients with possible GP, 39 patients were considered to have high radiological certainty of GP. Out of these 39, five patients had cancer instead. Thirty-three patients with confirmed GP formed the final study cohort. Patients with GP were mostly middle-aged (median 55 years) men. All had at least moderate alcohol consumption. No intervention was needed in 14 patients. In five-year follow-up all conservatively treated patients became asymptomatic, while 10 out of 16 patients undergoing at least one intervention were asymptomatic at five years.

CONCLUSION

The radiological diagnosis of GP is difficult, and a low threshold for cancer suspicion should be kept. Symptoms of GP decrease with time and suggest conservative treatment as the first-line option.

Benign vs malignant pancreatic lesions: Molecular insights to an ongoing debate

Several benign conditions such as chronic pancreatitis, autoimmune pancreatitis, and paraduodenal pancreatitis can present as mass lesions and may mimic pancreatic ductal adenocarcinoma (PDAC) clinically and radiologically. Thorough histologic examination with attention to certain morphologic features can assist in deciphering neoplastic from reactive, however small biopsies often remain a challenge. Variable histologic patterns in conventional PDAC may also confound the diagnosis of PDAC. Uncommon subtypes of pancreatic carcinoma such as adenosquamous and squamous cell carcinoma, colloid carcinoma, medullary carcinoma, hepatoid carcinoma and signet ring cell carcinoma necessitate excluding metastasis from other sites prior to rendering the diagnosis of pancreatic carcinoma. The use of immunohistochemical staining and molecular markers can aid in separating benign from malignant and PDAC from metastasis. PDAC expresses a few non-specific epithelial and mucin immunomarkers such as CK7, CK19, MUC1, MUC4 and MUC5AC. However, the only immunohistochemical marker that is specific for PDAC in the right clinical context is SMAD4. Loss of SMAD4 within atypical glands and ducts supports the diagnosis of PDAC in a limited sample. Unfortunately, this finding is seen only in 50% of PDAC cases. The identification of certain mutations can help support a diagnosis of PDAC when benign conditions are in the differential. At the molecular level, KRAS oncogene mutations are seen in approximately 93% of PDACs. Subsequent neoplastic progression is driven by additional mutations of tumor suppressor genes, such as CDKN2A, TP53, and SMAD4. Molecular markers can also provide an insight to the prognosis. For instance, the loss of SMAD4 is associated with a poor outcome whereas mutations in MLL, MLL2, MLL3, and ARID1A are associated with improved survival.

Pancreatoduodenectomy for paraduodenal pancreatitis: a diagnostic and therapeutic challenge

Paraduodenal pancreatitis (PP) is a rare type of focal pancreatitis involving the groove space. It mimics pancreatic head carcinoma, and its diagnosis and treatment are challenging. Pancreatoduodenectomy (PD) has traditionally been the primary surgical treatment for duodenal stenosis or suspected cancer.

We herein report a case of PP in a 65-year-old man. The patient was admitted to the hospital for postprandial epigastric pain and vomiting. A low-density mass between the uncinate process of the pancreas and the horizontal segment of the duodenum was suspected based on computed tomography findings. Both upper gastrointestinal radiography and gastrointestinal endoscopy showed an obstruction of the distal part of the descending duodenum. An operation was performed to release the obstruction and obtain a definitive diagnosis. A 3-cm mass in the groove area was compressing the third part of the duodenum, and PD was empirically performed. The final histopathological diagnosis was PP. Postoperatively, the patient developed anastomotic leakage of the gastrojejunostomy site with bleeding and was eventually discharged on postoperative day 51 after emergency surgery.

PP should be considered as a differential diagnosis of pancreatic ductal adenocarcinoma or duodenal stenosis, and accurate preoperative diagnosis preserves the opportunity for conservative or endoscopic management.

Swedish national guidelines for chronic pancreatitis

Chronic pancreatitis (CP) should be suspected in the case of recurrent upper abdominal pain of unknown origin and/or clinical signs of exocrine pancreatic insufficiency (EPI). Alcohol is the most common etiological factor associated with CP, others being smoking, male gender, and hereditary forms. CP is often associated with recurrent episodes of acute exacerbations.As of today, there is no accepted clinical definition of CP. However, irreversible morphological changes within the pancreas often occur, including dilatation of the main and branch pancreatic ducts, calcifications in ducts and parenchyma, parenchymal atrophy, and development of pseudocysts, though less so in the early phase of CP.

Cystic dystrophy of the duodenal wall: case report and literature review

Cystic dystrophy of the duodenal wall (CDDW) is an uncommon pathological condition that may be a cause of symptomatic duodenal mass in some patients. CDDW and closely related conditions that involve the duodenal wall and the pancreatoduodenal groove have gone by a variety names in the literature. Though their pathophysiology is not fully understood, they are thought to be due to the presence of heterotopic pancreatic tissue that undergoes a degenerative process. A multimodal imaging approach paired with biopsy is often employed to rule out malignancy in these patients. This case report provides an account of the radiological and pathological findings that helped lead to the diagnosis of CDDW. A review of relevant literature and a discussion of the presented case are provided.

Pancreas-preserving duodenal resections vs pancreatoduodenectomy for groove pancreatitis. Should we revisit treatment algorithm for groove pancreatitis?

BACKGROUND

The management of cystic dystrophy of the duodenal wall (CDDW), or groove pancreatitis (GP), remains controversial. Although pancreatoduodenectomy (PD) is considered the most suitable operation for CDDW, pancreas-preserving duodenal resection (PPDR) has also been suggested as an alternative for the pure form of GP (isolated CDDW). There are no studies comparing PD and PPDR for this disease.

AIM

To compare the safety, efficacy, and short- and long-term results of PD and PPDR in patients with CDDW.

METHODS

A retrospective analysis of the clinical, radiologic, pathologic, and intra- and postoperative data of 84 patients with CDDW (2004-2020) and a comparison of the safety and efficacy of PD and PPDR.

RESULTS

Symptoms included abdominal pain (100%), weight loss (76%), vomiting (30%) and jaundice (18%) and data from computed tomography, magnetic resonance imaging, and endoUS led to the correct preoperative diagnosis in 98.8% of cases. Twelve patients were treated conservatively with pancreaticoenterostomy (n = 8), duodenum-preserving pancreatic head resection (n = 6), PD (n = 44) and PPDR (n = 15) without mortality. Weight gain was significantly higher after PD and PPDR and complete pain control was achieved significantly more often after PPDR (93%) and PD (84%) compared to the other treatment modalities (18%). New onset diabetes mellitus and severe exocrine insufficiency occurred after PD (31% and 14%), but not after PPDR.

CONCLUSION

PPDR has similar safety and better efficacy than PD in patients with CDDW and may be the optimal procedure for the isolated form of CDDW. The pure form of GP is a duodenal disease and PD may be an overtreatment for this disease. Early detection of CDDW provides an opportunity for pancreas-preserving surgery.

Groove pancreatitis has a spectrum of severity and can be managed conservatively

BACKGROUND & AIMS

The natural history of groove pancreatitis is incompletely characterized. Published literature suggests a high rate of surgery. We describe the short- and long-term outcomes in a cohort of patients with groove pancreatitis treated at our institution.

METHODS

Medical records of patients hospitalized in the University of Pittsburgh Medical Center system from 2000 to 2014 and diagnosed with groove pancreatitis based on imaging were retrospectively reviewed. Clinical presentation and outcomes during index admission and follow-up were recorded.

RESULTS

Forty-eight patients with groove pancreatitis were identified (mean age 53.2 years, 79% male). Seventy-one percent were alcohol abusers and an equal number were cigarette smokers. Prior histories of acute and chronic pancreatitis were noted in 30 (62.5%) and 21 (43.8%), respectively. Forty-four (91.7%) met criteria for acute pancreatitis during their index admission. Alcohol was the most common etiology (68.8%). No patient experienced organ failure. The most frequent imaging findings were fat stranding in the groove (83.3%), duodenal wall thickening (52.1%), and soft tissue mass/thickening in the groove (50%). Over a mean follow-up of 5.0 years, seven (14.6%) required a pancreas-related surgery. Patients had a high burden of pancreatitis-related readmissions (68.8%, 69.4/100 patient-years). Incident diabetes and chronic pancreatitis were diagnosed in 5 (13.9% of patients at risk) and 8 (29.6% of patients at risk) respectively.

CONCLUSIONS

Groove pancreatitis has a wide spectrum of severity; most patients have mild disease. These patients have a high burden of readmissions and progression to chronic pancreatitis. A small minority requires surgical intervention.

Clinical Utility of Bile Duct Axis Deviation for Differential Diagnosis Between Pancreatic Head Cancer and Bile Duct Cancer

BACKGROUNDS

Differential diagnosis between pancreatic head cancer (PHC) and intrapancreatic bile duct cancer (BDC) is important, but no clinical standard has been established. Here we examine the diagnostic utility of bile duct axis deviation and other clinical factors for this differential diagnosis.

METHODS

This study enrolled patients who underwent pancreaticoduodenectomy for PHC or BDC at our center between 2009 and 2016. PHCs in groove or uncinate portions were excluded from analysis. From contrast-enhanced computed tomography images, the bile duct angle (BDA) was measured using three points: the junction of intrahepatic bile ducts, upper pancreatic edge, and Vater papilla. Logistic regression was performed to evaluate the diagnostic performance of BDA and other clinical factors for differential diagnosis.

RESULTS

During the study period, 22 PHCs and 31 BDCs were resected. The combination of BDA ≤ 130°, main pancreatic duct diameter ≥ 4.3 mm, and absence of jaundice predicted PHC rather than BDC with an area under the curve of the receiver-operator characteristics curve of .856 (95% confidence interval, .766-.947).

CONCLUSION

Clinical findings of larger bile duct axis deviation, main pancreatic duct dilation, and the absence of jaundice may be useful for distinguishing PHC from BDC.

Painless chronic pancreatitis

BACKGROUND

Painless chronic pancreatitis (CP) is a rare form of the disease.

AIM

To evaluate the prevalence and the characteristics of this overlooked form of pancreatitis.

METHODS

Patients with a diagnosis of CP and absence of pain were selected, excluding patients suffering from autoimmune pancreatitis. Clinical data, imaging features, and exocrine and endocrine function were therefore analyzed.

RESULTS

Among 781 patients observed between 2010 and 2016, 74 patients with painless CP (9.5%) were selected. Mean age at diagnosis was 60.8 (SD 10.8) years. 38(51%) individuals did not report any symptom, 36(49%) were affected by symptoms other than pain. Pancreatic calcifications were diagnosed in 70 patients (95%), main pancreatic duct dilation in 55(74%), and pancreatic atrophy in 39(53%).Thirty-six patients (55%) had severe exocrine pancreatic insufficiency(EPI). Diabetes was observed in 34 out of 72 patients (47%). During a mean follow-up of 2.9 (SD 2.8) years, only a mild pancreatitis was diagnosed in a 71-year old female. No patient underwent endoscopic treatment or surgery, developed pancreatic cancer or died.

CONCLUSIONS

In a tertiary center painless CP is observed in 10% of cases, and it is frequently associated with EPI. The probability of onset of pain is very low in a short-term follow-up.

Groove Pancreatitis Associated with Transient Liver Injury Mimicking Ampullary Neoplasm

Groove pancreatitis is an unusual form of pancreatitis characterized by fibrous inflammation and pseudo-tumor in the area around the head of the pancreas. The underlying etiology is unknown but is strongly linked to alcohol abuse. We report a 52-year-old male smoker with hypertension, asthma, and alcohol abuse who was admitted with severe epigastric pain radiating to the back. He was found to have acute pancreatitis. A computed tomography scan of the abdomen showed a mass lesion in the peri-ampullary region. MRI of the abdomen revealed dilated common bile duct and duodenal mass and features suggestive of groove pancreatitis. During the hospital stay, bilirubin and liver enzymes started to rise and then decreased gradually to the previous normal range. The secondary workup for liver disease was unremarkable. The patient improved and was discharged. Six-month follow-up showed regression of the duodenal lesion and reduction in the common bile duct dilatation. Excluding malignancy remains the main challenge in managing groove pancreatitis, and a conservative approach is more reasonable in cases with a typical profile.

Inflammatory mimickers of pancreatic adenocarcinoma

Pancreatic ductal adenocarcinoma can be a difficult imaging diagnosis early in its course given its subtle imaging findings such as focal pancreatic duct dilatation, abrupt duct cut-off, and encasement of vasculature. A variety of pancreatitidies have imaging findings that mimic pancreatic ductal adenocarcinoma and lead to mass formation making diagnosis even more difficult on imaging alone. These conditions include acute focal pancreatitis, chronic pancreatitis, autoimmune pancreatitis, and paraduodenal ("groove") pancreatitis. This review will focus on imaging findings that can help differentiate these inflammatory processes from pancreatic ductal adenocarcinoma.

Pancreaticoduodenectomy for paraduodenal pancreatitis is associated with a higher incidence of diabetes but a similar quality of life and pain control when compared to medical treatment

BACKGROUND

Paraduodenal pancreatitis is a focal form of chronic pancreatitis that affects the groove area between the duodenum and the head of the pancreas. Consensus regarding surgical or nonsurgical management as the best treatment option is still lacking.

METHODS

We retrospectively evaluated all patients managed for PP at The Pancreas Institute of the University Hospital Trust of Verona from 1990 to 2017. The outcomes of surgical vs. medical treatment with regard to pain control, quality of life and pancreatic insufficiency were evaluated through specific questionnaires.

RESULTS

The final study population consisted of 75 patients: 62.6% underwent surgery, and 37.4% were managed without surgery. All surgical procedures consisted of pancreaticoduodenectomy. The median follow-up from the diagnosis of paraduodenal pancreatitis was 60 (12-240) months. Patients who underwent surgery experienced a similar incidence of steatorrhea (44.7 vs. 52.6%; p = 0.4) but a significantly higher incidence of diabetes (59.6 vs. 10.7%; p < 0.01) when compared to those managed without surgery. There was no difference in terms of reported chronic pain (Graded Chronic Pain Scale, median 0 vs. 1; p = 0.1) and quality of life (Pancreatitis QoL Instrument, median 82 vs. 79; p = 0.2). However, surgical patients reported a worse level of self-care activities associated with glycemic control (Diabetes Self-Management Questionnaire, median 20 vs. 28, p = 0.02).

CONCLUSION

In patients affected by paraduodenal pancreatitis, surgery and medical therapy seem to obtain similar results in terms of quality of life and pain control. However, surgery is associated with an increased prevalence of postoperative diabetes with consequent relevant issues with self-care management. Surgery should be considered only in selected patients after adequate medical treatment.

Paraduodenal Pancreatitis: A Deceptive Abdominal Mass with Unique Histologic Findings

Paraduodenal pancreatitis (PP) is an uncommon abdominal pathology characterized by scarring of the pancreaticoduodenal space. Diagnosis of this inflammatory process is challenging as its clinical presentation is similar to that of pancreatic cancer. Currently, no definitive radiologic or pathologic features have been established to permit diagnosis of PP without surgical resection. However, the presence of eosinophilic concretions has been reported with increasing frequency in the histologic evaluation of PP. To the best of our knowledge, these concretions are distinctive for PP and not reported in neoplasms commonly involving the pancreaticoduodenal space. Herein, we discuss the case of a 60-year-old man who was found to have PP after pancreaticoduodenectomy for a paraduodenal mass with an initially nondiagnostic biopsy. Retrospective review of the preoperative FNA samples revealed eosinophilic concretions like those found in the final surgical specimen. If the identification of eosinophilic concretions in a background of inflammatory changes was to be accepted as a diagnostic criterion for PP, patients such as ours could be spared the morbidity associated with surgical resection.

Groove pancreatitis: a challenging imaging diagnosis

Groove pancreatitis (GP) is an uncommon form of chronic pancreatitis (CP) involving the space between duodenum, pancreatic head and common bile duct (CBD) known as pancreatic-duodenal groove. Although an association with long-standing ethanol assumption is reported a definite etiology of GP is unknown. Since thickening of the duodenal wall, pancreatic head enlargement, CBD stricture and dilatation of pancreatic duct system are common findings the differential diagnosis with pancreatic head neoplasm by means of imaging can be challenging. However, some imaging findings such as fibrotic changes of the pancreatic groove and presence of duodenal wall cysts may suggest the correct diagnosis. In this paper we review clinical and imaging features of GP with emphasis on computed tomography (CT) and magnetic resonance imaging (MRI) findings.

Role of total pancreatectomy in the treatment of paraduodenal pancreatitis: A case report

BACKGROUND

Paraduodenal pancreatitis (PP) is a rare form of chronic pancreatitis presenting with symptoms of duodenal obstruction. Conservative treatment is often unsuccessful and pancreaticoduodenectomy is the preferred surgical approach. A mini review of the outcomes of surgical therapy for PP shows that the results of pancreaticoduodenectomy are predominantly favorable.

CASE SUMMARY

In our case report of PP, we describe an unusual course first presenting with the symptoms of chronic pancreatitis and a pseudocyst of the pancreatic tail. A pseudocystojejunostomy was performed and the late postoperative course was complicated with the symptoms of duodenal obstruction. At laparotomy, PP was found and the patient was treated with a total pancreatectomy. The postoperative course was uneventful and good weight gain with resolution of pain was demonstrated at follow up visits.

CONCLUSION

Surgery is currently the optimal treatment option for PP. It is also the best diagnostic tool in distinguishing between pancreatitis and pancreatic adenocarcinoma.

Malformations, choristomas, and hamartomas of the gastrointestinal tract and pancreas

Congenital and hamartomatous lesions of the gastrointestinal tract cause diagnostic challenges for surgical pathologists. Many of these are merely histologic curiosities, whereas others have substantial clinical implications because they herald cancer syndromes or associated anomalies. Although a comprehensive discussion of all developmental abnormalities that can occur in the gastrointestinal tract is beyond the scope of a single manuscript, some entities are more likely to be encountered by surgical pathologists, have important clinical consequences, or pose diagnostic difficulties. The purpose of this review is to discuss the more common malformations and choristomas, as well as hamartomatous lesions that may be clinically important due to their risk for cancer development, frequent associations with heritable cancer syndromes and other anomalies, or potential to simulate other entities.

Comparison between groove carcinoma and groove pancreatitis

BACKGROUND/OBJECTIVES

The pancreatoduodenal groove (anatomical groove) is a potential space bordered by the head of the pancreas, duodenum, and common bile duct. Discerning between groove carcinoma (GC) and groove pancreatitis (GP) is often difficult, but clinically important. We retrospectively analyzed and compared the findings of computed tomography (CT), laboratory tests, and endoscopic ultrasound-fine needle aspiration (EUS-FNA) for GC and GP.

METHODS

GC (n = 36) and GP (n = 44) patients at Asan Medical Center from January 1, 2000, to May 31, 2017 were retrospectively reviewed. MDCT findings, baseline characteristics, laboratory test results, and EUS and EUS-FNA findings of GC and GP patients were compared.

RESULTS

CT showed no significant difference in groove enhancement between the groups. Mass-like lesions, cystic groove lesions, and calcification were observed in 86.1% and 15.9%, 38.9% and 75%, and 2.8% and 29.5% of GC and GP patients, respectively. Patients were tested for total bilirubin (GC: 2.0 vs. GP: 0.6 mg/dL), cancer antigen 19-9 (CA19-9) (GC: 76 vs. GP: 12.5 U/mL), and carcinoembryonic antigen (GC: 2.4 vs. GP: 2 ng/mL). Three GP patients died, and one GP patient was diagnosed with GC. However, among 30 GC patients with at least 1-year follow-up, 20 died. In multivariate logistic regression, CA19-9, and mass-like lesion on multidetector CT (MDCT) were discriminating factors between GC and GP. Among 23 (10 GC, 13 GP) patients who underwent EUS-FNA, the diagnostic sensitivity, specificity, positive predictive value, negative predictive value, accuracy of EUS-FNA were 90%, 100%, 100%, 92.86%, and 95.65%, respectively.

CONCLUSIONS

Several MDCT and laboratory findings favor GC over GP. EUS-FNA should be considered in patients with elevated CA19-9 levels and mass-like lesions on MDCT.

Groove Pancreatitis: Endoscopic Treatment via the Minor Papilla and Duct of Santorini Morphology

Background/Aims

Groove pancreatitis (GP) is an uncommon disease involving the pancreaticoduodenal area. Possible pathogenesis includes obstructive pancreatitis in the duct of Santorini and impaired communication with the duct of Wirsung, minor papilla stenosis, and leakage causing inflammation. Limited data regarding endoscopic treatment have been published.

Methods

Seven patients with GP receiving endoscopic treatment were reviewed. The morphology of the pancreatic duct was evaluated by a pancreatogram. Endoscopic dilation of the minor papilla and drainage of the duct of Santorini were performed.

Results

There were two pancreatic divisum cases, one ansa pancreatica case and four impaired connections between the duct of Santorini and the main pancreatic duct. Three to 31 sessions of endoscopy, with 2 to 24 sessions of transpapillary stenting and dilation, were performed. Interventions through the minor papilla were successfully performed in six of seven cases. The pancreatic stenting duration ranged from 2 to 87 months. Five patients with evidence of chronic pancreatitis (CP) tended to receive more endoscopic interventions than did the two patients without CP (2–24 vs 2, respectively) for GP and other complications associated with CP.

Conclusions

Disconnection or impairment of communication between the ducts of Santorini and Wirsung was observed in all cases of GP. No surgery was required, and endoscopic minor papilla dilation and drainage of the duct of Santorini were feasible for the treatment of GP.

Benign Tumors and Tumorlike Lesions of the Pancreas

The pancreas is a complex organ that may give rise to large number of neoplasms and non-neoplastic lesions. This article focuses on benign neoplasms, such as serous neoplasms, and tumorlike (pseudotumoral) lesions that may be mistaken for neoplasm not only by clinicians and radiologists, but also by pathologists. The family of pancreatic pseudotumors, by a loosely defined conception of that term, includes a variety of lesions including heterotopia, hamartoma, and lipomatous pseudohypertrophy. Autoimmune pancreatitis and paraduodenal ("groove") pancreatitis may also lead to pseudotumor formation. Knowledge of these entities will help in making an accurate diagnosis.

Pancreaticoduodenectomy and Outcomes for Groove Pancreatitis

BACKGROUND/AIMS

The operative management of groove pancreatitis (GP) is still a matter of controversy and pancreaticoduodenectomy (PD) can be a high-risk procedure for patients. The aim of this study was to report our 9-year experience of surgical resection for GP and to review relevant literature.

METHODS

A retrospective review of patients undergoing pancreatectomy for GP from August 1, 2008, through May 31, 2017 was performed. Patients with clinical, radiologic, and final pathologic confirmation of GP were included. Literature on the current understanding of GP was reviewed.

RESULTS

Eight patients from total 449 pancreatectomies met inclusion criteria. Four male and 4 female patients (mean age, 51.9 years; mean body mass index, 25.3) underwent pylorus-preserving pancreatoduodenectomy (3 by laparoscopy and 5 by open approach). Mean (range) operative time and blood loss was 343 (167-525) min and 218 (40-500) mL respectively. Pancreatic fistula and delayed gastric emptying were noted in one patient each. No major complications occurred, but minor complications occurred in 5 (62%) patients. Mean hospital stay was 6.1 (range 3-14) days. At median follow-up of 18.15 (interquartile range 7.25-33.8) months, all patients experienced a resolution of pancreatitis and improvement in symptoms.

CONCLUSIONS

PD is a safe procedure for GP. Short-term surgical outcomes are acceptable and long-term outcomes are associated with improved symptom control.

Ectopic pancreas in the upper gastrointestinal tract: Is endosonographic diagnosis reliable? Data from the German Endoscopic Ultrasound Registry and review of the literature

Background:

Ectopic pancreas (EP) belongs to the most frequent subepithelial lesions (SELs) of the upper gastrointestinal (GI) tract. In the majority of cases, it is detected incidentally. Differential diagnosis from mesenchymal subepithelial tumors may be difficult.

Methods:

Among 24,308 endosonographic examinations and interventions, which were prospectively enrolled in the database of the German Endoscopic Ultrasound (EUS) Registry from January 2009 to August 2013, 575 were performed for suspected SELs of the upper GI tract. Sixty three cases of EP of the upper GI tract (stomach, n = 53; duodenum, n = 10; esophagus, n = 0) were extracted and retrospectively reviewed.

Results:

In 65.1% of cases, radial echoendoscopes or radial miniprobes were used for examination. Nearly 84% of EP was found in the stomach, 16% in the duodenum, none in the esophagus. In 88.9% of cases, the EUS examination discerned the layer of origin. In 59% of cases EP was described as a heterogeneous, in 28.6% as a homogeneous-hypoechoic and in 7.9% as a homogeneous-echogenic subepithelial mass lesion. Mean diameter was 13.0 mm × 8.1 mm, the mean ratio between long and short axis diameter was 1.75. EUS-guided fine needle aspiration (EUS-FNA) was used to accomplish cytological or histological diagnosis in only 6.3% of cases.

Conclusions:

EP accounts for 11% of all EUS examinations performed for subepithelial lesions of the upper GI tract and prospectively enrolled in the German EUS registry. Rather than being an eyecatcher, EP is a chameleon with numerous differential diagnoses. In selected cases, EUS-FNA may help clarifying the diagnosis.

Case 248: Cystic Duodenal Dystrophy with Groove Pancreatitis

History A 59-year-old man presented to the gastroenterology outpatient department with acute abdominal pain centered in the epigastrium. He had experienced similar episodes of abdominal pain in the past that had been treated with surgery. He reported multiple failed attempts at upper gastrointestinal endoscopy. Laboratory tests were performed at the time of admission and revealed a serum glutamic-oxaloacetic transaminase level of 9 U/L [0.15 μkat/L] (normal range, 5-40 U/L [0.08-0.67 μkat/L]), a serum glutamic-pyruvic transaminase level of 34 U/L [0.57 μkat/L] (normal range, 5-45 U/L [0.08-0.75 μkat/L]), a serum γ-glutamyltransferase level of 210 U/L (3.50 μkat/L) (normal range, 10-50 U/L [0.17-0.83 μkat/L]), a serum alkaline phosphatase level of 157 U/L (2.62 μkat/L) (normal range, 30-120 U/L [0.50-2.0 μkat/L]), a serum amylase level of 210 U/L (3.50 μkat/L) (normal range, 30-100 U/L [0.50-1.66 μkat/L]), a serum lipase level of 391 U/L (6.52 μkat/L) (normal range, 13-60 U/L [0.21-1.0 μkat/L]), an α-fetoprotein level of 3.81 ng/ mL (normal range, 0-9 ng/mL), a total protein level of 4.6 g/dL (normal range, 6.0-8.5 g/dL), and an albumin level of 2.6 g/dL (normal range, 3.5-5.2 g/dL). The rest of the laboratory data were unremarkable. The patient underwent erect abdominal radiography, contrast material-enhanced multidetector row computed tomography (CT) of the abdomen with 100 mL of iohexol (300 mg iodine per milliliter, Omnipaque; GE Healthcare, Shanghai, China) followed by combined positron emission tomography (PET) and CT (hereafter, PET/CT) with 6.9 mCi of fluorodeoxyglucose (FDG) and magnetic resonance (MR) imaging of the upper abdomen.

Paraduodenal pancreatitis: benign and malignant mimics at MRI

Paraduodenal pancreatitis, also known as groove pancreatitis, is a rare form of chronic pancreatitis that masquerades as pancreatic adenocarcinoma affecting the pancreaticoduodenal groove, a potential space between the head of the pancreas, duodenum, and common bile duct. Two forms of groove pancreatitis have been described. The segmental form involves the pancreatic head with development of scar tissue within the groove, whereas the pure form affects the groove only, sparing the pancreatic head. Imaging findings of groove pancreatitis often overlap with primary duodenal, ampullary, or pancreatic neoplasms, which often results in a diagnostic challenge. In addition, paraduodenal pancreatitis can be mistaken for cystic pancreatic lesions, especially when there is involvement of the duodenal wall. Preoperative recognition of this entity is very important in order to avoid unnecessary procedures, although surgery, such as pancreaticoduodenectomy, may still be required to relieve obstructive symptoms. In this article, the pathophysiology and magnetic resonance imaging characteristics of paraduodenal pancreatitis and important benign and malignant mimics are discussed.

Paraduodenal pancreatitis as a mimicker of pancreatic adenocarcinoma: MRI evaluation

PURPOSE

To evaluate the MRI features of paraduodenal pancreatitis (PDP) and to define useful signs to differentiate PDP from pancreatic ductal adenocarcinoma (PDAC).

MATERIAL AND METHODS

We reviewed the MRI scans of 56 patients, 28 affected by PDP and 28 by PDAC, all pathologically proven. The following parameters were evaluated: signal intensity of the lesion on T1-, T2-WI, DWI (b800) and after contrast medium administration; presence of cysts; dilation of common hepatic duct and main pancreatic duct; focal thickening of the second portion of the duodenum; maximum diameter and volume of the lesion.

RESULTS

Both PDPs and PDACs were more frequently hypointense on T1-WI, iso-hyperintense on T2-WI, hypointense in the pancreatic phase and iso-hypointense in the venous phase (p>0.05); in the delayed phase most PDP were hyperintense (p=0.0031); on DWI 71.4% PDPs were isointense and all PDACs were hyperintense (p=0.0041). Cystic components were present in 85.7% PDPs (p=0.0011); double duct sign was present in 50% PDACs (p=0.0048); focal thickening of the duodenum was depicted in 89.3 PDPs (p=0.0012). PDPs were larger than PDACs (p=0.0003).

CONCLUSION

The most suggestive signs of PDP are: signal hyperintensity in the delayed phase, isointensity on DWI, presence of cysts, focal thickening of the duodenum and large size of the lesion.

Diagnosing Chronic Pancreatitis: Comparison and Evaluation of Different Diagnostic Tools

OBJECTIVES

This study aims to compare the M-ANNHEIM, Büchler, and Lüneburg diagnostic tools for chronic pancreatitis (CP).

METHODS

A cross-sectional analysis of the development of CP was performed in a prospectively collected multicenter cohort including 669 patients after a first episode of acute pancreatitis. We compared the individual components of the M-ANNHEIM, Büchler, and Lüneburg tools, the agreement between tools, and estimated diagnostic accuracy using Bayesian latent-class analysis.

RESULTS

A total of 669 patients with acute pancreatitis followed-up for a median period of 57 (interquartile range, 42-70) months were included. Chronic pancreatitis was diagnosed in 50 patients (7%), 59 patients (9%), and 61 patients (9%) by the M-ANNHEIM, Lüneburg, and Büchler tools, respectively. The overall agreement between these tools was substantial (κ = 0.75). Differences between the tools regarding the following criteria led to significant changes in the total number of diagnoses of CP: abdominal pain, recurrent pancreatitis, moderate to marked ductal lesions, endocrine and exocrine insufficiency, pancreatic calcifications, and pancreatic pseudocysts. The Büchler tool had the highest sensitivity (94%), followed by the M-ANNHEIM (87%), and finally the Lüneburg tool (81%).

CONCLUSIONS

Differences between diagnostic tools for CP are mainly attributed to presence of clinical symptoms, endocrine insufficiency, and certain morphological complications.