Nonneoplastic mimickers of pancreatic neoplasms

Groove pancreatitis: From enigma to future directions-A comprehensive review

Groove pancreatitis (GP) is a rare and clinically distinct form of chronic pancreatitis affecting the pancreaticoduodenal groove comprising the head of the pancreas, duodenum, and the common bile duct. It is more prevalent in individuals in their 4-5th decade of life and disproportionately affects men compared with women. Excessive alcohol consumption, tobacco smoking, pancreatic ductal stones, pancreatic divisum, annular pancreas, ectopic pancreas, duodenal wall thickening, and peptic ulcers are significant risk factors implicated in the development of GP. The usual presenting symptoms include severe abdominal pain, nausea, vomiting, diarrhea, weight loss, and jaundice. Establishing a diagnosis of GP is often challenging due to significant clinical and radiological overlap with numerous benign and malignant conditions affecting the same anatomical location. This can lead to a delay in initiation of treatment leading to increasing morbidity, mortality, and complication rates. Promising research in artificial intelligence (AI) has garnered immense interest in recent years. Due to its widespread application in diagnostic imaging with a high degree of sensitivity and specificity, AI has the potential of becoming a vital tool in differentiating GP from pancreatic malignancies, thereby preventing a missed or delayed diagnosis. In this article, we provide a comprehensive review of GP, covering the etiology, pathogenesis, clinical presentation, radiological and endoscopic evaluation, management strategies, and future directions. This article also aims to increase awareness about this lesser known and often-misdiagnosed clinical entity amongst clinicians to ultimately improve patient outcomes.

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.

The Rate of Avoidable Pancreatic Resections at a High-Volume Center: An Internal Quality Control and Critical Review

BACKGROUND

The incidence of benign diseases among pancreatic resections for suspected malignancy still represents a relevant issue in the surgical practice. This study aims to identify the preoperative pitfalls that led to unnecessary surgeries at a single Austrian center over a twenty-year period.

METHODS

Patients undergoing surgery for suspected pancreatic/periampullary malignancy between 2000 and 2019 at the Linz Elisabethinen Hospital were included. The rate of "mismatches" between clinical suspicion and histology was considered as primary outcome. All cases that, despite that, fulfilled the indication criteria for surgery were defined as minor mismatches (MIN-M). Conversely, the true avoidable surgeries were identified as major mismatches (MAJ-M).

RESULTS

Among the 320 included patients, 13 (4%) presented with benign lesions at definitive pathology. The rate of MAJ-M was 2.8% (n = 9), and the most frequent causes of misdiagnoses were autoimmune pancreatitis (n = 4) and intrapancreatic accessory spleen (n = 2). In all MAJ-M cases, various mistakes within the preoperative workup were detected: lack of multidisciplinary discussion (n = 7, 77.8%); inappropriate imaging (n = 4, 44.4%); lack of specific blood markers (n = 7, 77.8%). The morbidity and mortality rates for mismatches were 46.7% and 0.

CONCLUSION

All avoidable surgeries were the result of an incomplete pre-operative workup. The adequate identification of the underlying pitfalls could lead to minimize and, potentially, overcome this phenomenon with a concrete optimization of the surgical-care process.

Groove Pancreatitis: A Case Report and Review of a Hidden Type of Chronic Pancreatitis

Groove pancreatitis is a chronic type of segmental or focal pancreatitis seen to affect the groove, which is the region between the head of the pancreas, the duodenum, and the common bile duct. Despite its incidence remaining unknown, it accounts for 2.7% to 24.5% of pancreaticoduodenectomies performed for chronic pancreatitis. A diverse etiology has been implicated but the exact cause is yet to be identified. As it closely mimics pancreatic malignancy and remains mostly undiagnosed preoperatively, many patients often end up undergoing a pancreaticoduodenectomy. Awareness of this entity and early diagnosis will help us address this issue with more conservative measures than by resorting to a morbid procedure such as a pancreaticoduodenectomy.

We report a case of a 50-year-old male, a chronic alcoholic, with a two-year history of upper abdominal pain, postprandial vomiting, and weight loss. An abdominal contrast-enhanced computed tomography (CECT) scan was suggestive of either a pancreatic malignancy or a possibility of groove pancreatitis. However, postoperative histopathological examination confirmed the lesser known groove pancreatitis. Here, we review the clinical, radiological, and pathological characteristics of groove pancreatitis, as its diagnosis and management still pose a challenge.

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.

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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.

Autoimmune pancreatitis: Current perspectives

Over the last two decades, our knowledge and understanding regarding the pathogenesis and biology of autoimmune pancreatitis (AIP) have improved tremendously. Type 1 AIP or IgG4-related pancreatitis (IgG4-RP) is now believed to be the prototype of the multisystemic IgG4-related disease. In view of clinical features like obstructive jaundice and mass-forming lesions in the pancreas in elderly men, type 1 AIP often mimics pancreatic cancer. IgG4-related sclerosing cholangitis concomitantly involving the extrahepatic and intrahepatic biliary tree is the most common extrapancreatic involvement seen in up to 80% of these patients, which needs to distinguish from cholangiocarcinoma. Histology is characterised by lymphoplasmacytic inflammation, abundant IgG4 positive plasma cell infiltration, storiform fibrosis and obliterative phlebitis. Apart from histology, high serum IgG4 levels, pancreatic parenchymal and duct imaging findings and other organ involvement aid in diagnosis especially in cases where definitive histology is not evident. Also, these parameters lay the foundation of various diagnostic criteria proposed over last few years. On the contrary, histology alone is the mainstay for establishing diagnosis of idiopathic duct-centric pancreatitis (IDCP) as it lacks any specific serological marker or imaging. Since both types of AIP respond dramatically to corticosteroid treatment, a biopsy is crucial to establish the preoperative diagnosis and to exclude malignancy so as to avoid unnecessary surgery. This review discusses the morphologic spectrum, treatment and prognosis of IgG4-RP and IDCP with an emphasis on approach to diagnosis with relevant histologic features, differential diagnoses and the challenges faced during biopsy interpretation.

Inflammatory Pseudotumor of the Pancreas Mimicking a Pancreatic Neoplasm

A 78-year-old woman was admitted to our hospital with a pancreatic tumor, incidentally discovered in an abdominal ultrasound exam. She was asymptomatic and without any previous personal pathological condition. The computed tomography (CT) and the magnetic resonance imaging (MRI) scan showed a mass lesion of 4 cm in diameter, located in the pancreatic body, conditioning the invasion of the splenic vein. The patient was admitted to surgery. During the laparotomy, we found a tumoral lesion highly suspicious of pancreatic neoplasia located in the transition of the head/body of the pancreas, with an invasion of the portal vein and several peri-regional lymph nodes. We performed biopsies of the pancreatic mass and lymphadenectomy of the peri-regional pancreatic lymph nodes. Histological analysis found an inflammatory pseudotumor of the head/body of the pancreas, without signals of malign epithelial neoplasm and also without criteria for immunoglobulin G4-related disease. During the follow-up, a PET/CT and MRI confirmed that the pancreatic lesion had disappeared without any treatment. Inflammatory pseudotumor of the pancreas is a rare entity not fully understood. Despite this, the administration of corticosteroids and immunosuppressive therapy could be taken into consideration as the disease carries a risk.

Usefulness of non-contrast MR imaging in distinguishing pancreatic ductal adenocarcinoma from focal pancreatitis

BACKGROUND

Accurate differentiation between pancreatic adenocarcinoma and focal pancreatitis is challenging.

PURPOSE

To investigate the usefulness of non-contrast MRI by comparing with multidetector row CT (MDCT) and gadoxetic acid-enhanced MRI in the discrimination of pancreatic ductal adenocarcinoma (PDAC) and focal pancreatitis (FP).

MATERIALS AND METHODS

This retrospective study included 187 patients (116 with PDACs and 71 with FP) who underwent gadoxetic acid-MRI and MDCT prior to surgical resection or biopsy. The MRI features of PDAC and FP were compared by two radiologists. Then, two observers independently reviewed the three imaging sets: MDCT, non-contrast MRI (T1-, T2-weighted, and diffusion-weighted images), and MRI with and without gadoxetic acid to determine the diagnostic performances of each imaging modality in the discrimination of PDAC and FP.

RESULTS

The significant features on non-contrast MRI for diagnosis of PDAC included peritumoral cyst, pancreatic duct cut-off, clear hypointensity on T1WI, and bile duct dilatation (P < 0.05). Presence of peritumoural cyst showed the highest odds ratio for predicting PDAC. Non-contrast MRI was superior to MDCT in differentiating PDAC from FP with regard to accuracy (84.5% vs 95.5% for observer 1; 85.8% vs. 96.0% for observer 2), sensitivity (83.6% vs. 98.3%; 84.5% vs 97.8%), and negative predictive value (76.3% vs. 97.0%; 77.6% vs 96.4%) (P < 0.05). We found similar diagnostic values between the non-contrast MRI and MRI with and without contrast (P > 0.05) for both observers.

CONCLUSION

Non-contrast MRI is better than MDCT and comparable to MRI with and without gadoxetic acid in differentiating PDAC from FP.

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.

IgG4-related disease: with emphasis on the biopsy diagnosis of autoimmune pancreatitis and sclerosing cholangitis

In 2011, chronic fibroinflammatory processes occurring simultaneously or metachronously in various organs and associated with elevated IgG4 serum levels and/or tissue infiltration with IgG4-positive plasma cells have been recognized as manifestations of a systemic disorder called IgG4-related disease (IgG4-RD). The histologic key findings are lymphoplasmacytic infiltration rich in IgG4-positive plasma cells combined with storiform fibrosis and obliterative phlebitis. Among the organs mainly affected by IgG4-RD are the pancreas and the extrahepatic bile ducts. The pancreatic and biliary alterations have been described under the terms autoimmune pancreatitis (AIP) and sclerosing cholangitis, respectively. These diseases are currently more precisely called IgG4-related pancreatitis (or type 1 AIP to distinguish it from type 2 AIP that is unrelated to IgG4-RD) and IgG4-related sclerosing cholangitis (IgG4-related SC). Clinically and grossly, both diseases commonly imitate pancreatic and biliary adenocarcinoma, tumors that are well known for their dismal prognosis. As IgG4-RD responds to steroid treatment, making a resection of a suspected tumor unnecessary, a biopsy is often required to establish the preoperative diagnosis. This review discusses the morphologic spectrum of IgG4-related pancreatitis and IgG4-related SC and focuses on the biopsy relevant histologic features for the diagnosis and differential diagnosis of these diseases.

Pancreatic head excavation for tissue diagnosis may reduce unnecessary pancreaticoduodenectomies in the setting of chronic pancreatitis

BACKGROUND

The necessity to obtain a tissue diagnosis of cancer prior to pancreatic surgery still remains an open debate. In fact, a non-negligible percentage of patients undergoing pancreaticoduodenectomy (PD) for suspected cancer has a benign lesion at final histology. We describe an approach for patients with diagnostic uncertainty between cancer and chronic pancreatitis, with the aim of minimizing the incidence of PD for suspicious malignancy finally diagnosed as benign disease.

METHODS

Eighty-eight patients (85.4%) with a clinicoradiological picture highly suggestive for malignancy received formal PD (group 1). Fifteen patients (14.6%) in whom preoperative diagnosis was uncertain between pancreatic cancer and chronic pancreatitis underwent pancreatic head excavation (PHEX) for intraoperative tissue diagnosis (group 2): those diagnosed as having cancer received PD, whereas those with chronic pancreatitis received pancreaticojejunostomy (PJ).

RESULTS

No patient received PD for benign disease. All patients in group 1 had adenocarcinoma on final histology. Eight patients of group 2 (53.3%) received PD after intraoperative diagnosis of cancer, whereas 7 (46.7%) received PJ because no malignancy was found at introperative frozen sections. No signs of cancer were encountered in patients receiving PHEX and PJ after a median follow-up of 42 months. Overall survival did not differ between patients receiving PD for cancer in the group 1 and those receiving PD for cancer after PHEX in the group 2 (P=0.509).

CONCLUSION

Although the described technique has been used in a very selected group of patients, our results suggest that PHEX for tissue diagnosis may reduce rates of unnecessary PD, when the preoperative diagnosis is uncertain between cancer and chronic pancreatitis.

Groove Pancreatitis: Report of Three Cases with Brief Review of Literature

Groove pancreatitis (GP) is a rare type of segmental pancreatitis, and it remains largely an unfamiliar entity to most physicians. It is often misdiagnosed as pancreatic cancer and autoimmune pancreatitis. With better understanding of radiological findings, preoperative differentiation is often possible. If there is preoperative diagnosis of GP, one can employ non-surgical treatment. But most of the patients ultimately require surgery. Pancreaticoduodenectomy (PD) is the surgical treatment of choice. We report three cases of GP that were treated by Whipple's operation at our unit. All the three patients had a history of long-standing alcohol intake. In the first and third patients, we had a preoperative diagnosis of GP. But, in the second patient, our pre-operative and intra-operative diagnosis was a pancreatic head malignancy. Diagnosis of GP was made only after histopathological examination. All the three patients had uneventful postoperative recovery and were well at 55-, 45- and 24-month follow-up respectively. In addition to detail descriptions of our three cases, a detailed review of the current literature surrounding this clinical entity is also provided in this article.

A Man with Pancreatic Head Mass Lesion on Endoscopic Ultrasound and Granuloma on Cytopathology

Primary pancreatic lymphoma is an unlikely malignancy accounting for less than 0.5% of pancreatic tumors. Clinical presentation is often nonspecific and may be clinically misdiagnosed as pancreatic adenocarcinoma. Here we present an Iranian case of primary pancreatic lymphoma in a 47-year-old male suffering from jaundice and 20% weight loss. Endoscopic ultrasound revealed a mixed echoic mass lesion at the head of pancreas. The patient underwent endoscopic ultrasound-guided fine needle aspiration of solid pancreatic mass and histopathologic diagnosis revealed granuloma. Computed tomography-guided core needle biopsy was performed and eventually histological examination showed granuloma that was coherent with the diagnosis of primary pancreatic lymphoma. Primary pancreatic lymphoma is a rare entity presenting with nonspecific symptoms, laboratory and radiological findings. Computed tomography results in combination with clinical and radiological studies generally provide guidance for appropriate investigation.

Clinical outcomes and prevalence of cancer in patients with possible groove pancreatitis

BACKGROUND AND AIM

Data on non-surgical treatment of groove pancreatitis (GP) and the risk of cancer are lacking. We aimed to determine the prevalence and predictors of cancer in patients in whom the diagnosis GP was considered, and to evaluate symptom improvement after treatment.

STUDY

Patients referred with possible GP (2001-2014) were retrospectively included. An experienced radiologist reassessed imaging. GP patients received questionnaires evaluating their symptoms.

RESULTS

From the 38 possible GP patients, 10 had cancer (26%) and 28 GP (74%). Compared with cancer patients, GP patients more frequently had cysts (2/10 vs. 18/28, P = 0.03), less often jaundice (6/10 vs 3/27, P < 0.01), an abrupt caliber change of the CBD (5/10 vs. 2/28, P < 0.01) or suspicious cytology (5/9 vs 2/20, P = 0.02). Of the 28 GP patients, 14 patients were treated conservatively of whom 12 reported symptom improvement after a median follow-up of 45 months (range 7-127 months). All 6 patients treated endoscopically and 7/8 patients treated surgically reported symptom improvement. Surgery, performed because of treatment failure (3/8) or inability to exclude malignancy (5/8), caused mortality in 1/8 patients.

CONCLUSIONS

Suspicion of pancreatic cancer should be high in patients presenting with possible GP. Conservative, endoscopic and surgical treatment can all lead to symptom improvement, suggesting a 'step-up approach' to GP once cancer is excluded.

Endoscopic ultrasound-guided fine needle aspiration biopsy of pancreatic lesions. An 8-year analysis of single institution material focusing on efficacy and learning progress

OBJECTIVE

To evaluate the efficacy and the learning curve of the endoscopic ultrasound-guided fine needle aspiration biopsy (EUS-FNAB) diagnostics of pancreatic lesions over 8 years (2007-2014).

MATERIAL AND METHODS

EUS-FNAB using a Linear Echoendoscope Olympus was performed in 531 patients, mostly without rapid on-site evaluation (ROSE). Smears plus cytoblock sections were used routinely. Immunocytochemistry was utilised as indicated.

RESULTS

The average, satisfactory sampling rate increased from the 61.2% in the first 3-year period to 72.9% in the last 3-year period (P = 0.008). The availability of the material for cytoblocks increased from 36.4% in the first period to 75.3% in the last period (P = 0.017). The efficacy of cytoblocks increased from 39.6% to 46.2% (P = 0.086). Comparing the first and last 3-year periods, the indication for immunocytochemistry did not rise substantially (5.2% and 8.5% respectively), but the predictive value of immunocytochemistry rose from 56.3% to 100.0% (P = 0.001). The most frequent diagnostic result was malignancy confirmation - both primary (41.2%) and metastatic (2.1%). In cases with representative samples and follow-up information, the specificity, sensitivity, positive predictive value and accuracy were high from the beginning. The negative predictive value decreased slightly in the last 3-year period.

CONCLUSION

The pancreatic EUS-FNAB without ROSE represents a suboptimal arrangement conditioned with our staff/time/location reality. Nevertheless, within the last 3 years of our activity, nearly three-quarters of patients profit from the diagnostic contribution of this procedure.

Groove Pancreatitis: A Rare form of Chronic Pancreatitis

Context:

Groove pancreatitis is a rare form of chronic pancreatitis affecting the “groove” of the pancreas among the pancreatic head, duodenum, and common bile duct. The exact cause is unknown, although there are associations with long-term alcohol abuse, smoking, peptic ulcer disease, heterotopic pancreas, gastric resection, biliary disease, and anatomical or functional obstruction of the minor papilla. The diagnosis can be challenging. Endoscopic ultrasound (EUS) and magnetic resonance cholangiopancreatography are the preferred imaging modalities. The treatment of choice is conservative although surgical intervention can sometimes be required.

Case Report:

A 57-year-old male with a history of human immunodeficiency virus and hepatitis B presented with 4 days of epigastric pain. Abdominal exam revealed absent bowel sounds and epigastric tenderness. He had a creatinine of 1.72 mg/dL, potassium of 2.9 mmol/L, and a normal lipase level of 86 U/L. Liver enzymes and total bilirubin were normal. Computed tomography abdomen showed high-grade obstruction of the second portion of the duodenum without any obvious mass. An esophagogastroduodenoscopy showed a mass at the duodenal bulb causing luminal narrowing, with biopsies negative for malignancy. Magnetic resonance imaging revealed a mass in the region of the pancreatic head and descending duodenum. EUS revealed a 3 cm mass in the region of pancreatic head with irregular borders and no vascular invasion. Fine needle aspiration (FNA) was nondiagnostic. The patient then underwent a Whipple's procedure. Pathology of these specimens was negative for malignancy but was consistent with para-duodenal or groove pancreatitis.

Conclusion:

The low incidence of groove pancreatitis is partly due to lack of familiarity with the disease. Groove pancreatitis should be considered in the differential for patients presenting with pancreatic head lesions and no cholestatic jaundice, especially when a duodenal obstruction is present, and neither duodenal biopsies nor pancreatic head FNA confirm adenocarcinoma.

Difficult Diagnostic Problems in Pancreatobiliary Neoplasia

CONTEXT

Many common diagnostic dilemmas are encountered in pancreatobiliary pathology, frequently resulting in uncertainty on behalf of the pathologist and referral for a second opinion.

OBJECTIVES

To review 4 common diagnostic dilemmas encountered in the practice of pancreatobiliary pathology: (1) pancreatic ductal adenocarcinoma versus chronic pancreatitis; (2) pancreatic ductal carcinoma versus adenocarcinomas arising in the ampulla and intrapancreatic common bile duct; (3) the distinction of uncommon intraductal neoplasms--intraductal oncocytic papillary neoplasm, intraductal tubulopapillary neoplasm, and intraductal acinar cell carcinoma; and (4) intrahepatic cholangiocarcinoma versus metastatic carcinoma.

DATA SOURCES

A review of pertinent literature, along with the authors' personal experience, based on institutional and consultation materials.

CONCLUSIONS

Important diagnostic features for a few challenging problems in pancreatobiliary pathology are reviewed. Careful study of the microscopic features along with awareness of differential diagnoses and diagnostic pitfalls generally allows distinction of these entities. We also highlight established and novel ancillary studies that help to arrive at an accurate diagnosis.

Clinicoradiological appraisal of 'paraduodenal pancreatitis': Pancreatitis outside the pancreas!

Purpose:

Paraduodenal pancreatitis (PP) is a unique form of focal chronic pancreatitis that selectively involves the duodenum and aberrant pancreatic tissue located near the minor papilla (beyond the pancreas proper). The pseudotumoral nature of the disease often generates considerable clinical quandary and patient apprehension, and therefore merits a better understanding. The present study appraises the clinicoradiological manifestations of PP in 33 patients.

Materials and Methods:

Clinical, laboratory, and radiological manifestations of 33 patients of PP treated in gastroenterology/hepatology and hepato-pancreatico-biliary surgery units during June 2010-August 2014 were retrospectively reviewed.

Results:

All patients were young to middle-aged men (100%) with history of alcohol abuse (93.9%) and/or smoking (42.4%), who presented either with acute or gradually worsening abdominal pain (90.9%). Pancreatic enzymes and serum tumor markers remained normal or were mildly/transiently elevated. Cystic variant was detected in 57.6% (solid in 42.4%); the disease remained confined to the groove/duodenum (pure form) in 45.4%. Medial duodenal wall thickening with increased enhancement was seen in 87.87 and 81.81%, respectively, and duodenal/paraduodenal cysts were seen in 78.78%. Pancreatic calcifications and biliary stricture were seen 27.3% patients. Peripancreatic arteries were neither infiltrated nor encased.

Conclusion:

PP has a discrete predilection for middle-aged men with history of longstanding alcohol abuse and/or smoking. Distinguishing imaging findings include thickening of the pancreatic side of duodenum exhibiting increased enhancement with intramural/paraduodenal cysts. This may be accompanied by plate-like scar tissue in the groove region, which may simulate groove pancreatic carcinoma. However, as opposed to carcinoma, the peripancreatic arteries are neither infiltrated nor encased, rather are medially displaced.

Frequency and characterization of benign lesions in patients undergoing surgery for the suspicion of solid pancreatic neoplasm

OBJECTIVES

A diagnosis of benign lesions (BLs) is reported in 5% to 21% of pancreatoduodenectomies performed for neoplasms; no data for body-tail resections are available. The aims were to investigate the frequency and characterize the BLs mimicking cancer in the head and the body-tail of the pancreas.

METHODS

This study is a retrospective review of pancreatic specimenscollected from 2005 to 2011 in the pathology database of Mainz (Germany). Patients with final diagnosis excluding malignancy were analyzed by histology, imaging, and clinical aspects.

RESULTS

Among 373 patients, 33 patients (8.8%) were diagnosed with a benign disease: 25 (8.4%) of 298 in the pancreatic head and 8 (10.7%) of 75 in the body-tail resections. Paraduodenal pancreatitis was diagnosed in 13 (3.5%) of 373 patients; autoimmune pancreatitis (AIP), in 11 (2.9%); "ordinary" chronic pancreatitis, in 6 (1.6%); and accessory spleen, in 3 (0.8%). In pancreatic head resections, the most frequent diagnoses were paraduodenal pancreatitis (13/298, 4.4%) and AIP (9/298, 3%), whereas in the body-tail, the most frequent diagnoses were accessory spleen (3/75, 4%), chronic pancreatitis (3/75, 4%), and AIP (2/75, 2.7%).

CONCLUSIONS

Benign lesions are observed with the same frequency inspecimens of the head or the body-tail of the pancreas.

Immunosuppressive drugs for the treatment of autoimmune pancreatitis

Autoimmune pancreatitis is one of the few diseases of the pancreas characterized by the possibility of curing the illness using immunosuppressant drugs. In this paper, the therapeutic approach used to treat autoimmune pancreatitis patients and the clinical outcome related to each treatment modality were reviewed. Steroids are useful in alleviating the symptoms of the acute presentation of autoimmune pancreatitis, but some questions remain open, such as a shared definition of the disease’s remission as well as autoimmune pancreatitis relapse, the dosage of steroids in the symptomatic phase of the disease and the duration of steroid therapy. Finally, it should be determined if other immunosuppressive nonsteroidal drugs could become first-line therapy in patients with autoimmune pancreatitis without jaundice and without atrophic pancreas.

Short-term and long-term outcomes for patients with autoimmune pancreatitis after pancreatectomy: a multi-institutional study

BACKGROUND

Autoimmune pancreatitis (AIP) is a rare subtype of chronic pancreatitis that may mimic adenocarcinoma of the pancreas. The aim of this study was to evaluate the short-term and long-term outcomes of pancreatectomy for patients with AIP.

METHODS

In this multi-institutional study, we identified all patients who underwent pancreatectomy for AIP from 1986 to 2011. AIP was confirmed by pathology review. Clinical presentation, operative details, and postoperative outcomes were analyzed.

RESULTS

Seventy-four patients (median age, 60 years; 69 % male) with AIP underwent pancreatectomy. The main indication for operation was concern for malignancy (n = 59, 80 %). No patients were found to have pancreatic adenocarcinoma on final pathology. Major complications occurred in ten (14 %) patients, with one perioperative death (1 %). Clinically relevant (grade B/C) pancreatic fistulae occurred in two patients. No patients required reoperation for AIP and 11 (17 %) patients developed recurrent AIP.

CONCLUSION

Although we do not advocate pancreatectomy for AIP, strong suspicion of malignancy may require an operation in selected patients. For patients with AIP, pancreatectomy resulted in few pancreatic fistulae, a low rate of re-intervention, and a 17 % recurrence rate.

Fine-needle aspiration features of paraduodenal pancreatitis (groove pancreatitis): a report of three cases

Chronic pancreatitis is notorious for mimicking both the clinical and radiologic presentation of pancreatic carcinoma. Paraduodenal pancreatitis is believed to result from focal chronic pancreatitis which affects the minor papilla of the duodenum. Currently, there is limited information available regarding the cytologic features of paraduodenal pancreatitis. In this study, we report the cytologic features of three patients with paraduodenal pancreatitis who had EUS-guided FNAs of the pancreas. The cytologic features were highly variable between cases, likely due to sampling of the various components of paraduodenal pancreatitis. The most common findings were spindled stromal cells, foamy cells, and granular debris. Although most often interpreted as negative for malignancy, the sampling of an area with abundant spindle cells or Brunner gland hyperplasia can mimic neoplasia. Careful attention to the clinical history and radiologic description can help to prevent over-diagnosis on FNA.

An abundance of IgG4+ plasma cells is not specific for IgG4-related tubulointerstitial nephritis

IgG4-related tubulointerstitial nephritis (IgG4-TIN), the renal parenchymal lesion of IgG4-related sclerosing disease, is characterized, among other things, by the presence of numerous IgG4-positive plasma cells (IgG4+PC) in the kidney infiltrate. The specificity of this finding for IgG4-TIN has not been addressed. To address this we examined 100 consecutive renal biopsy samples with active interstitial inflammation for the presence of IgG4+PC, and correlated the findings with principal diagnosis, the available clinical histories, and the findings in four biopsy samples of IgG4-TIN. Eleven of the survey biopsy samples contained an average of more than 10 IgG4+PC per × 200 field, including two with IgG4+PC in numbers comparable to those in two of the IgG4-related tubulointerstitial disease biopsy samples. The principal pathological diagnoses in the IgG4+PC-rich cases included anti-neutrophil cytoplasmic antibody-positive necrotizing glomerulonephritis (five cases), diabetic nephropathy (two cases), idiopathic interstitial nephritis (two cases), membranous glomerulonephritis (one case), and lupus nephritis (one case). There was no reason, based on histology or clinical history, to believe that any of these cases represented previously unsuspected IgG4-related tubulointerstitial disease. We conclude that the presence of numerous IgG4+PC is essential to, but not sufficient for, the diagnosis of IgG4-TIN.

Direct visualization of indeterminate pancreaticobiliary strictures with probe-based confocal laser endomicroscopy: a multicenter experience

BACKGROUND

Because of the low sensitivity of current ERCP-guided tissue sampling methods, management of patients with indeterminate pancreaticobiliary strictures is a challenge. Probe-based confocal laser endomicroscopy (pCLE) enables real-time microscopic visualization of strictures during an ongoing ERCP.

OBJECTIVE

To document the utility, performance, and accuracy of real-time pCLE diagnosis compared with histopathology.

DESIGN

Prospective observational study within the framework of a multicenter registry.

SETTING

Five academic centers.

PATIENTS

This study involved 102 patients with indeterminate pancreaticobiliary strictures.

INTERVENTION

Clinical information, ERCP findings, tissue sampling results, and pCLE videos were collected prospectively. Investigators were asked to provide a presumptive diagnosis based on pCLE during the procedure before pathology results were available. All patients received at least 30 days of follow-up until definitive diagnosis of malignancy was established or 1-year follow-up if index tissue sampling was benign.

MAIN OUTCOME MEASUREMENTS

Diagnostic accuracy, sensitivity, specificity of ERCP-guided pCLE compared with ERCP with tissue acquisition.

RESULTS

There were no pCLE-related adverse events in the study. We were able to evaluate 89 patients, of whom 40 were proven to have cancer. The sensitivity, specificity, positive-predictive value, and negative-predictive value of pCLE for detecting cancerous strictures were 98%, 67%, 71%, and 97%, respectively, compared with 45%, 100%, 100%, and 69% for index pathology. This resulted in an overall accuracy of 81% for pCLE compared with 75% for index pathology. Accuracy for combination of ERCP and pCLE was significantly higher compared with ERCP with tissue acquisition (90% vs 73%; P = .001).

LIMITATIONS

Investigators had access to all relevant clinical information, which may have biased the predictive characteristics of pCLE.

CONCLUSION

Probe-based CLE provides reliable microscopic examination and has excellent sensitivity and negative predictive value. The significantly higher accuracy of ERCP and pCLE compared with ERCP with tissue acquisition may support supplementing ERCP with pCLE.

Therapeutic management and clinical outcome of autoimmune pancreatitis

BACKGROUND

Autoimmune pancreatitis, in comparison to other benign chronic pancreatic diseases, is characterized by the possibility of curing the illness with immunosuppressant drugs. The open question is whether to differentiate autoimmune pancreatitis as a primary or secondary disease based on the presence or absence of other autoimmune diseases or whether to consider autoimmune pancreatitis a clinical and pathological systemic entity, called IgG4-related sclerosing disease, since this aspect is also very important from a therapeutic point of view.

METHODS

In this paper, we reviewed the conventional therapeutic approach used to treat autoimmune pancreatitis patients and the clinical outcome related to each treatment modality. We also reviewed some aspects which are important for the correct management of autoimmune pancreatitis, such as the surgical approach, the outcome of surgically treated autoimmune pancreatitis patients, whether medical treatment is always necessary, and, finally, when medical treatment should be initiated.

CONCLUSIONS

Steroids are useful in alleviating the symptoms of the acute presentation of autoimmune pancreatitis, but some questions remain open such as the dosage of steroids in the acute phase and the duration of steroid therapy; finally, it should be assessed if other immunosuppressive non-steroidal drugs may become the first-line therapy in patients with AIP without jaundice and without atrophic pancreas.

Pancreatic Cystic Lesions of Nonmucinous Type

Cystic lesions of nonmucinous type can arise within the pancreas or can develop from adjacent structures and appear to involve the pancreas. In addition, some typically solid masses can become cystic or can present as cystic lesions. Nonmucinous cysts can be neoplastic, inflammatory, reactive, or congenital. The vast majority of neoplastic nonmucinous cysts are benign. Because of the difficulty in determining the neoplastic potential of a pancreatic cyst preoperatively, many non-neoplastic cysts are resected. This article reviews the surgical pathology of nonmucinous cysts.

Pancreatitis, Other Inflammatory Lesions, and Pancreatic Pseudotumors

The pancreas is versatile in the diversity of disorders that it can exhibit. In this article, characteristics of disorders such as chronic, autoimmune, eosinophilic, hereditary, and infectious pancreatitis are described. With regard to autoimmune pancreatitis, the role of clinical evaluation, histologic examination, and IgG4 immunohistochemistry is discussed. The role of pancreatitis in the pathogenesis of diabetes is also mentioned. Some implications of pancreatitis are highlighted, including the neoplastic predisposition caused by inflammatory lesions of the pancreas. The goal of this article is to convey an appreciation of these disorders because their recognition can benefit patients tremendously, as inflammatory lesions of the pancreas can be mass-forming, giving rise to pseudotumors, and leading to surgical resection that may otherwise be unnecessary.

Ductal Adenocarcinoma of the Pancreas

Pancreatic ductal adenocarcinoma (PDAC) and its variants comprise between 80% and 90% of all tumors of the exocrine pancreas. Because of its silent course, late clinical manifestation, and rapid growth, it is considered a silent killer. Only 10% to 15% of cases are resectable and the 5-year survival rate remains lower than 5%. The differential diagnosis between PDAC and chronic pancreatitis is a challenge for pathologists. This article provides a guide for pathologic evaluation of PDAC specimens with the macroscopic and microscopic features of common PDAC and its variants and discusses the differential diagnosis and morphologic and immunophenotypical prognostic parameters.

Characteristic clinical and pathologic features for preoperative diagnosed groove pancreatitis

Purpose

Groove pancreatitis is a rare specific form of chronic pancreatitis that extends into the anatomical area between the pancreatic head, the duodenum, and the common bile duct, which are referred to as the groove areas. We present the diagnostic modalities, pathological features and clinical outcomes of a series of symptomatic patients with groove pancreatitis who underwent pancreaticoduodenectomy.

Methods

Six patients undergoing pancreaticoduodenectomy between May 2006 and May 2009 due to a clinical diagnosis of symptomatic groove pancreatitis were retrospectively included in the study.

Results

Five cases were male and one case was female, with a median age at diagnosis of 50 years. Their chief complaints were abdominal pain and vomiting. Abdominal computed tomography, endoscopic ultrasound and endoscopic retrograde cholangiopancreatography were performed. Preoperative diagnosis of all patients was groove pancreatitis. Histological finding was compatible with clinically diagnosed groove pancreatitis in five patients and the pathologic diagnosis of the remaining patient was adenocarcinoma of distal common bile duct. Following pancreaticoduodenectomy, four living patients experienced significant pain alleviation.

Conclusion

The diagnostic imaging modalities of choice for groove pancreatitis are computed tomography and endoscopic ultrasonography. If symptomatic groove pancreatitis is suspected, careful follow-up of patients is necessary and pancreaticoduodenectomy seems to be a reasonable treatment option.

Transcription factor MIST1 in terminal differentiation of mouse and human plasma cells

Despite their divergent developmental ancestry, plasma cells and gastric zymogenic (chief) cells share a common function: high-capacity secretion of protein. Here we show that both cell lineages share increased expression of a cassette of 269 genes, most of which regulate endoplasmic reticulum (ER) and Golgi function, and they both induce expression of the transcription factors X-box binding protein 1 (Xbp1) and Mist1 during terminal differentiation. XBP1 is known to augment plasma cell function by establishing rough ER, and MIST1 regulates secretory vesicle trafficking in zymogenic cells. We examined morphology and function of plasma cells in wild-type and Mist1(-/-) mice and found subtle differences in ER structure but no overall defect in plasma cell function, suggesting that Mist1 may function redundantly in plasma cells. We next reasoned that MIST1 might be useful as a novel and reliable marker of plasma cells. We found that MIST1 specifically labeled normal plasma cells in mouse and human tissues, and, moreover, its expression was also characteristic of plasma cell differentiation in a cohort of 12 human plasma cell neoplasms. Overall, our results show that MIST1 is enriched upon plasma cell differentiation as a part of a genetic program facilitating secretory cell function and also that MIST1 is a novel marker of normal and neoplastic plasma cells in mouse and human tissues.

Italian consensus guidelines for chronic pancreatitis

This paper gives practical guidelines for diagnosis and treatment of chronic pancreatitis. Statements have been elaborated by working teams of experts, by searching for and analysing the literature, and submitted to a consensus process by using a Delphi modified procedure. The statements report recommendations on clinical and nutritional approach, assessment of pancreatic function, treatment of exocrine pancreatic failure and of secondary diabetes, treatment of pain and prevention of painful relapses. Moreover, the role of endoscopy in approaching pancreatic pain, pancreatic stones, duct narrowing and dilation, and complications was considered. Recommendations for most appropriate use of various imaging techniques and of ultrasound endoscopy are reported. Finally, a group of recommendations are addressed to the surgical treatment, with definition of right indications, timing, most appropriate procedures and techniques in different clinical conditions and targets, and clinical and functional outcomes following surgery.

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

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

Autoimmune pancreatitis

BACKGROUND

Autoimmune pancreatitis (AIP) is a relatively newly recognized type of pancreatitis that is characterized by diffuse or focal swelling of the pancreas due to lymphoplasmacytic infiltration and fibrosis of the pancreatic parenchyma.

MATERIAL AND METHODS

A PubMed literature search was performed using the keywords "autoimmune pancreatitis". Sometimes, bibliographies were cross-referenced and related article searches were performed once an article of interest was identified.

RESULTS

Pathologically, AIP shows narrowing of the pancreatic ducts and the intrapancreatic portion of the common bile duct. Obstructive jaundice is a common symptom at presentation, and pancreatic cancer represents an important clinical differential diagnosis. In late stages of the disease, the normal pancreatic parenchyma is often replaced by large amounts of fibrosis. Histologically, there seem to be two subtypes of the disease-one showing infiltration with IgG4-positive plasma cells but lacking granulocytic epithelial lesions (GELs), the other showing GELs but lacking strong IgG4 positivity. AIP is in at least some instances the pancreatic manifestation of a clinicopathological entity of IgG4-related systemic sclerosing disease. On the basis of pancreatic imaging, together with serological measurement of IgG4 and evaluation of other organ involvement, many AIP patients can be identified. The remaining patients require further diagnostic work-up. In these patients, pancreatic core needle biopsy and, as AIP responds to steroid treatment, also a trial with steroids, can help to differentiate AIP from pancreatic cancer. OUTLOOK AND DISCUSSION: This review presents the pathological, radiologic and laboratory findings of AIP. Moreover, the treatment and pathogenesis are discussed.