Groove pancreatitis: MRI and pathologic findings

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.

Groove pancreatitis presenting with upper gastrointestinal obstruction and abnormal renal function: A case report and literature review

Groove pancreatitis (GP) is a rare type of chronic pancreatitis characterized by fibrotic lesions localized to the groove between the pancreatic head, duodenum, and common bile duct. We present a case of a 59-year-old male alcoholic with vomiting and renal dysfunction found to have duodenal obstruction and low-density pancreatic head lesions on computed tomography concerning for GP. The patient underwent pancreaticoduodenectomy and pathology confirmed the diagnosis postoperatively. The patient recovered well without complications or relapse at follow-up. Although rare, GP should be included in the differential for pancreatic head masses in middle-aged alcoholics and surgical resection may be necessary for symptom relief and exclusion of malignancy.

Diagnostic value of endoscopic ultrasound in groove pancreatitis

Aim: Groove pancreatitis (GP) is a rare type of chronic pancreatitis characterized by varying degrees of thickening and scarring of the duodenal wall, duodenal lumen stenosis, mucosal hypertrophy with plicae and cyst formation. GP is primarily observed in middle-aged male patients with a history of alcohol consumption. Clinical symptoms are usually non-specific, and there is currently no unified diagnostic standard. However, imaging methods, particularly endoscopic ultrasound (EUS), are useful for diagnosis. EUS-guided biopsy can provide a strong basis for the final diagnosis. This review summarizes the value of EUS and its derivative technologies in the diagnosis, differential diagnosis and treatment of GP.Methods: After searching in PubMed and Web of Science databases using 'groove pancreatitis (GP)' and 'endoscopic ultrasonography (EUS)' as keywords, studies related were compiled and examined.Results: EUS and its derivative technologies are of great significance in the diagnosis, differential diagnosis, and treatment of GP, but there are still limitations that need to be comprehensively applied with other diagnostic methods to obtain the most accurate results.Conclusion: EUS has unique value in both the diagnosis and treatment of GP. Clinicians need to be well-versed in the advantages and limitations of EUS for GP diagnosis to select the most suitable imaging diagnostic method for different cases and to reduce the unnecessary waste of medical resources.

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.

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.

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.

Atypical and uncommon CT and MR imaging presentations of pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinomas (PDACs) occasionally have atypical and uncommon imaging presentations that can present a diagnostic dilemma and result in false interpretation. This article aimed to illustrate these CT and MR imaging findings, including isoattenuating PDAC, coexisting acute pancreatitis, PDAC with a cystic feature, groove PDAC, diffuse PDAC, hypointensity on diffusion-weighted imaging (DWI), multifocal PDAC, intratumoral calcification, and extrapancreatic invasion with a barely discernable mass. A subset of PDACs with atypical features are occasionally encountered during routine clinical practice. Knowledge of and attention to these atypical and uncommon variable imaging features may allow radiologists to avoid misinterpretation and a delayed diagnosis.

Imaging of Ampullary and Periampullary Conditions

The ampulla of Vater is formed by the union of the pancreatic duct and the common bile duct and is also known as hepatopancreatic ampulla or hepatopancreatic duct. The ampulla is surrounded by a muscular valve known as the sphincter of Oddi, which controls the flow of bile and pancreatic juices into the duodenum in response to food. The ampulla is also an important embryological landmark as it marks the anatomical transition from foregut to the midgut. Because of this, it is a watershed zone where the blood supply changes from the celiac axis to the superior mesenteric artery. Radiologic evaluation of the ampulla and the periampullary region is challenging because it requires an understanding of the embryology, the normal appearance, and different anatomic variants. Also, a wide variety of pathologies can occur in this region. The purpose of this review is to present the normal anatomy of the ampulla and the periampullary region on different imaging modalities and to summarize the imaging features of the common variants, and benign and malignant ampullary and periampullary conditions. Understanding of the normal anatomical appearance and variants along with the knowledge of common pathologic conditions affecting the ampulla and periampullary conditions can help radiologists in making accurate diagnosis resulting in optimum patient care.

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.

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.

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.

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.

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.

Heterotopic Pancreas: Histopathologic Features, Imaging Findings, and Complications

Heterotopic pancreas is a congenital anomaly in which pancreatic tissue is anatomically separate from the main gland. The most common locations of this displacement include the upper gastrointestinal tract-specifically, the stomach, duodenum, and proximal jejunum. Less common sites are the esophagus, ileum, Meckel diverticulum, biliary tree, mesentery, and spleen. Uncomplicated heterotopic pancreas is typically asymptomatic, with the lesion being discovered incidentally during an unrelated surgery, during an imaging examination, or at autopsy. The most common computed tomographic appearance of heterotopic pancreas is that of a small oval intramural mass with microlobulated margins and an endoluminal growth pattern. The attenuation and enhancement characteristics of these lesions parallel their histologic composition. Acinus-dominant lesions demonstrate avid homogeneous enhancement after intravenous contrast material administration, whereas duct-dominant lesions are hypovascular and heterogeneous. At magnetic resonance imaging, the heterotopic pancreas is isointense to the orthotopic pancreas, with characteristic T1 hyperintensity and early avid enhancement after intravenous gadolinium-based contrast material administration. Heterotopic pancreatic tissue has a rudimentary ductal system in which an orifice is sometimes visible at imaging as a central umbilication of the lesion. Complications of heterotopic pancreas include pancreatitis, pseudocyst formation, malignant degeneration, gastrointestinal bleeding, bowel obstruction, and intussusception. Certain complications may be erroneously diagnosed as malignancy. Paraduodenal pancreatitis is thought to be due to cystic degeneration of heterotopic pancreatic tissue in the medial wall of the duodenum. Recognizing the characteristic imaging features of heterotopic pancreas aids in differentiating it from cancer and thus in avoiding unnecessary surgery. ^© RSNA, 2017.

Clinical and Morphological Features of Paraduodenal Pancreatitis: An Italian Experience With 120 Patients

OBJECTIVES

This study aimed to evaluate the clinical and radiological features and clinical outcomes of paraduodenal pancreatitis (PP).

METHODS

A final diagnosis of PP was based on surgical specimens in resected patients and on imaging in nonoperated patients. Clinical, radiological, and pathological data were collected and reevaluated.

RESULTS

We studied 120 patients, 97.5% of whom were drinkers and 97.5% were smokers. Symptoms at clinical onset were acute pancreatitis in 78 patients (65%) and continuous pain in 68 patients (55.8%). Other symptoms were vomiting (36.7%), weight loss (25.8%), and jaundice (11.7%). Cystic variant was diagnosed in 82 patients (68.0%), and solid variant was diagnosed in 38 patients (32.0%). Pure and diffuse forms were observed in 22 (18.3%) and 98 (81.7%) patients, respectively. Pancreatic calcifications were present at clinical onset in 5.0% of the patients and in 61.0% at the end of follow-up. Somatostatin analogs were used in 13 patients (10.8%), and 81 patients (67.0%) underwent surgery.

CONCLUSIONS

The clinical profile of PP was found to be middle-aged men who were heavy drinkers and smokers with painful pancreatitis and was associated with vomiting and weight loss. In nonresponders, alcohol withdrawal and medical therapy can be proposed as a first-line treatment, and surgery as a second-line treatment.

Groove pancreatitis-a great mimicker

Groove pancreatitis is an uncommon form of chronic pancreatitis affecting the "groove" between the pancreatic head, duodenum and common bile duct. Many radiologists remain unfamiliar with this entity, with only a few descriptions of it existing in the radiology and pathology literature. The exact underlying cause of groove pancreatitis is unclear, although there are strong associations with peptic ulcer disease, smoking, long-term alcohol abuse, functional obstruction of the duct of Santorini and Brunner gland hyperplasia. This entity mimics pancreatic carcinoma and often ultimately leads to surgery. Hence it is important for radiologists to be familiar with imaging findings of groove pancreatitis to avoid diagnostic dilemma. Imaging findings in our case showed a soft tissue mass in the pancreaticoduodenal groove with enhancement, consistent with scar tissue and cystic changes within the lesion. It was associated with adjacent duodenal wall thickening with smooth and regular tapering of the pancreatic and common bile ducts.

Pathologic Evaluation and Reporting of Intraductal Papillary Mucinous Neoplasms of the Pancreas and Other Tumoral Intraepithelial Neoplasms of Pancreatobiliary Tract: Recommendations of Verona Consensus Meeting

BACKGROUND

There are no established guidelines for pathologic diagnosis/reporting of intraductal papillary mucinous neoplasms (IPMNs).

DESIGN

An international multidisciplinary group, brought together by the Verona Pancreas Group in Italy-2013, was tasked to devise recommendations.

RESULTS

(1) Crucial to rule out invasive carcinoma with extensive (if not complete) sampling. (2) Invasive component is to be documented in a full synoptic report including its size, type, grade, and stage. (3) The term "minimally invasive" should be avoided; instead, invasion size with stage and substaging of T1 (1a, b, c; ≤ 0.5, > 0.5-≤ 1, > 1 cm) is to be documented. (4) Largest diameter of the invasion, not the distance from the nearest duct, is to be used. (5) A category of "indeterminate/(suspicious) for invasion" is acceptable for rare cases. (6) The term "malignant" IPMN should be avoided. (7) The highest grade of dysplasia in the non-invasive component is to be documented separately. (8) Lesion size is to be correlated with imaging findings in cysts with rupture. (9) The main duct diameter and, if possible, its involvement are to be documented; however, it is not required to provide main versus branch duct classification in the resected tumor. (10) Subtyping as gastric/intestinal/pancreatobiliary/oncocytic/mixed is of value. (11) Frozen section is to be performed highly selectively, with appreciation of its shortcomings. (12) These principles also apply to other similar tumoral intraepithelial neoplasms (mucinous cystic neoplasms, intra-ampullary, and intra-biliary/cholecystic).

CONCLUSIONS

These recommendations will ensure proper communication of salient tumor characteristics to the management teams, accurate comparison of data between analyses, and development of more effective management algorithms.

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.

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.

Groove Pancreatitis: A Brief Review of a Diagnostic Challenge

Groove pancreatitis is an uncommon, yet well-described, type of focal chronic pancreatitis, affecting “the groove”—the area between the head of the pancreas, the duodenum, and the common bile duct. Men aged 40 to 50 years are most commonly affected, with a history of alcohol abuse frequently disclosed. Clinical manifestations are similar to other forms of chronic pancreatitis, and vomiting secondary to duodenal stenosis is the main feature. It is postulated that pancreatitis in the groove area arises from obstruction of pancreatic juices in the ductal system, causing fibrosis and stasis with resultant inflammation of surrounding structures. The minor papilla is frequently the anatomic area of preferential involvement. Groove pancreatitis poses diagnostic challenges, forming a “pseudotumor” that mimics pancreatic carcinoma. The distinction is important, although often impossible to make because of their similar presentation, with groove pancreatitis usually affecting younger patients. Most patients are successfully treated with pancreaticoduodenectomy when definitive pathologic diagnoses can be made.

Paraduodenal pancreatitis

Paraduodenal pancreatitis is a distinct clinicopathological entity involving the duodenum and the pancreatic tissue in the vicinity of the minor papilla. Most afflicted patients are young alcoholic males who present clinically with upper abdominal pain, weight loss, nausea, and vomiting. Pancreatic tissue elements in the duodenal wall and impedance to exocrine pancreatic secretions at the minor papilla are key factors in the pathogenesis of this condition. On imaging, the condition may manifest as a solid fibrotic mass around the minor papilla or as cysts in the duodenum and the pancreaticoduodenal groove. Duodenal stenosis, biliary strictures, chronic calcifying pancreatitis, and pancreatic ductal dilatation are also often observed.

Groove pancreatitis: spectrum of imaging findings and radiology-pathology correlation

OBJECTIVE

Groove pancreatitis is a rare form of chronic pancreatitis affecting the "groove" between the pancreatic head, duodenum, and common bile duct. The exact cause is unknown, although there are strong associations with long-term alcohol abuse, functional obstruction of the duct of Santorini, and Brunner gland hyperplasia.

CONCLUSION

Unfortunately, differentiating groove pancreatitis from malignancy on the basis of imaging features, clinical presentation, or laboratory markers can be extraordinarily difficult, and the vast majority of these patients ultimately undergo a pancreaticoduodenectomy (Whipple procedure) because of an inability to completely exclude malignancy. In certain cases, however, the imaging features on CT and MRI can allow the radiologist to prospectively suggest the correct diagnosis.

Paraduodenal pancreatitis: clinical performance of MR imaging in distinguishing from carcinoma

PURPOSE

To evaluate the diagnostic performance of contrast material-enhanced magnetic resonance (MR) imaging for distinguishing paraduodenal pancreatitis (PDP) from pancreatic head duct adenocarcinoma (CA) in patients with diagnoses confirmed by histopathologic analysis.

MATERIALS AND METHODS

This retrospective study was approved by the institutional review board and is HIPAA compliant. Between July 2007 and July 2010, 47 patients who underwent Whipple procedure and MR imaging less than 60 days before surgery were identified retrospectively. Two relatively inexperienced fellowship trainees with 9 months of body fellowship training were asked to record the presence or absence of three MR imaging features: focal thickening of the second portion of the duodenum; abnormal enhancement of the second portion of the duodenum; and cystic focus in the expected region of the accessory pancreatic duct. Strict criteria for diagnosis of PDP included presence of all three imaging features. Any case that did not fulfill the criteria was classified as CA. Sensitivity, specificity, positive predictive value, and negative predictive value for characterization of PDP was calculated for each reader with 95% confidence intervals. A κ test assessed level of agreement between readers.

RESULTS

Each reader correctly categorized 15 of 17 (88.2%) PDP cases when all three imaging criteria were met. Alternatively, 26 of 30 (86.7%) pancreatic duct CA were correctly categorized as inconsistent with PDP. Four patients with histopathologic diagnosis of CA were incorrectly classified as PDP by each reader. Agreement between the two readers showed substantial κ agreement for the diagnosis of PDP and differentiation from pancreatic duct CA.

CONCLUSION

Contrast-enhanced MR imaging may help accurately identify PDP and distinguish it from CA when strict diagnostic criteria are followed.

SUPPLEMENTAL MATERIAL

http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.13112056/-/DC1.

Cystic dystrophy of the duodenal wall is not always associated with chronic pancreatitis

Cystic dystrophy of the duodenal wall is a rare form of the disease which was described in 1970 by French authors who reported the presence of focal pancreatic disease localized in an area comprising the C-loop of the duodenum and the head of the pancreas. German authors have defined this area as a “groove”. We report our recent experience on cystic dystrophy of the paraduodenal space and systematically review the data in the literature regarding the alterations of this space. A MEDLINE search of papers published between 1966 and 2010 was carried out and 59 papers were considered for the present study; there were 19 cohort studies and 40 case reports. The majority of patients having groove pancreatitis were middle aged. Mean age was significantly higher in patients having groove carcinoma. The diagnosis of cystic dystrophy of the duodenal wall can now be assessed by multidetector computer tomography, magnetic resonance imaging and endoscopic ultrasonography. These latter two techniques may also add more information on the involvement of the remaining pancreatic gland not involved by the duodenal malformation and they may help in differentiating “groove pancreatitis” from “groove adenocarcinoma”. In conclusion, chronic pancreatitis involving the entire pancreatic gland was present in half of the patients with cystic dystrophy of the duodenal wall and, in the majority of them, the pancreatitis had calcifications.

Sonographic findings in groove pancreatitis

Groove pancreatitis is a rare form of chronic pancreatitis involving the anatomic plane between the pancreatic head and duodenum. The radiographic diagnosis remains challenging, and most patients undergo exploratory laparotomy on suspicion of a periampullary malignancy. The appearance of groove pancreatitis on transabdominal and intraoperative sonography has rarely been reported in the literature. The sonographic findings in our 2 patients included a hypoechoic thin area between the pancreatic head and duodenum, a hyperechoic and thickened wall of the adjacent duodenum, and a heterogeneous or hyperechoic dorsocranial part of the pancreatic head.

Groove pancreatitis: A Case Report and Review of the Literature

Groove pancreatitis is a rare form of segmental chronic pancreatitis. It involves the anatomic space between the head of the pancreas, the duodenum and the common bile duct. It was first described in the early 1970s, but it remains largely unfamiliar to most physicians. Radiological diagnosis can be challenging, as it is often difficult to differentiate it from other entities. The differential diagnosis from pancreatic head carcinoma may be difficult and recognition of subtle differences between these two entities is extremely important as the management differs significantly. Groove pancreatitis can be managed by conservative medical treatment, and surgery is reserved only for patients with persistent and severe clinical symptoms. We present a case of a 27 year-old male with groove pancreatitis and discuss the Magnetic Resonance Imaging (MRI) appearance of this entity as well as the differential diagnosis.

Nonalcoholic, nonbiliary pancreatitis: cross-sectional imaging spectrum

OBJECTIVE

The purpose of this review is to describe the epidemiologic, etiopathogenetic, clinical, and imaging characteristics of various nonalcoholic, nonbiliary pancreatitis syndromes.

CONCLUSION

The spectrum of nonalcoholic, nonbiliary pancreatitis includes autoimmune pancreatitis, groove pancreatitis, hereditary pancreatitis, tropical pancreatitis, tuberculous pancreatitis, and metabolic pancreatitis. Advances in genetics and molecular pathology have shed new light on the etiopathogenesis and course of these syndromes. Accurate diagnosis aided by imaging findings allows optimal management.

A comprehensive, case-based review of groove pancreatitis

Groove pancreatitis is an uncommon form of focal chronic pancreatitis that involves the duodenal wall or "groove" area (between the pancreas, common bile duct, and duodenum). It remains largely an unfamiliar entity to most physicians and is often misdiagnosed as pancreatic malignancy or autoimmune pancreatitis because of its "pseudotumor" formation. In this case series, we present 4 cases of groove pancreatitis which highlight important clinical aspects of this disease entity. We then provide a review of the pathophysiology, diagnosis, and treatment of this condition. We hope to clarify the salient aspects of this disease process and make groove pancreatitis a more recognized entity to the clinician.

Groove pancreatitis: a diagnostic challenge

Groove pancreatitis is a distinct form of chronic pancreatitis characterized by inflammation and fibrous tissue formation, affecting the groove area between the head of the pancreas, the duodenum and the common bile duct. It is manifested on imaging by a sheet-like mass in the groove area near the minor papilla. Thickening of the duodenal wall and cystic transformation in the duodenal wall also represent common imaging features. Pathogenesis is still unclear, and clinical presentation is not specific. Endoscopic ultrasonography (EUS), computed tomography (CT) and magnetic resonance imaging (MRI) demonstrate imaging findings consistent with the disease in typical cases, but specific diagnosis is challenging in a number of patients where biopsy is required. The disease may mimic pancreatic, common bile duct or duodenal wall cancer that requires prompt and excessive surgical intervention, as opposed to groove pancreatitis where initial conservative treatment is suggested. The clinical, histopathological and radiological features on cross-sectional imaging of this entity are discussed in this review, and differential diagnostic clues are given.