Groove pancreatic carcinomas: radiological and pathological findings

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

BACKGROUND

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

CASE SUMMARY

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

CONCLUSION

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

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.

Surgical Management of Groove Pancreatitis: A Case Report

Groove pancreatitis (GP) is a chronic type of pancreatitis involving the groove area between the head of the pancreas, the duodenum, and the common bile duct. Alcohol abuse is one of the main pathogenetic factors, although its etiology is not clearly defined. Differential diagnosis of pancreatic disorders remains difficult. The lack of diagnostic management and the restrictive number of patients are the main barriers. This article presents a case of a 37-year-old male diagnosed with GP after several episodes of epigastric pain and vomiting, with a history of chronic alcohol consumption. The patient's radiological and laboratory results excluded the possibility of malignancy and suggested the diagnosis of groove pancreatitis with duodenal stenosis. After initial conservative treatment failed, surgical management was decided. A gastroenteroanastomosis was made in order to bypass the duodenum aiming for a total resolution of the symptoms and an uneventful recovery of the patient. Although most studies suggest pancreatoduodenectomy (Whipple's procedure) as the treatment of choice, a less major procedure can be performed in evidence of malignancy absence.

Groove Pancreatitis-Tumor-like Lesion of the Pancreas

Groove pancreatitis (GP) is an uncommon appearance of pancreatitis represented by fibrous inflammation and a pseudo-tumor in the area over the head of the pancreas. The underlying etiology is unidentified but is firmly associated with alcohol abuse. We report the case of a 45-year-old male patient with chronic alcohol abuse who was admitted to our hospital with upper abdominal pain radiating to the back and weight loss. Laboratory data were within normal limits, except for the level of carbohydrate antigen (CA) 19-9. An abdominal ultrasound and computed tomography (CT) scan revealed swelling of the pancreatic head and duodenal wall thickening with luminal narrowing. We performed an endoscopic ultrasound (EUS) with fine needle aspiration (FNA) from the markedly thickened duodenal wall and the groove area, which revealed only inflammatory changes. The patient improved and was discharged. The principal objective in managing GP is to exclude a diagnosis of malignancy, whilst a conservative approach might be more acceptable for patients instead of extensive surgery.

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.

Paraduodenal pancreatitis - problem in the groove

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

Diagnosis, natural course and treatment outcomes of groove pancreatitis

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

How Does Ultrasound Manage Pancreatic Diseases? Ultrasound Findings and Scanning Maneuvers

As ultrasound (US) is simple and less invasive than other imaging modalities, this technique is widely used for mass screening. However, visualizing the entire pancreas due to complicated anatomy, obesity and overlying gas can be difficult. US plays a key role in the diagnosis of pancreatic carcinoma (PC), of which tumors smaller than 10 mm (TS1a) and pancreatic carcinoma <i>in situ</i> are expected to have good prognosis. To detect these forms of PC, main pancreatic duct (MPD) dilatation (3 mm or more) and pancreatic cysts (5 mm or larger) are US findings of high-risk individuals (HRIs), and these subjects should be observed periodically. Scanning maneuvers are also important for both screening for PC and follow-up of HRIs. As lesions in the groove area and ventral pancreas do not affect the MPD or extrahepatic bile duct, we should pay attention to these areas. Visualization of the tail is also challenging due to gas and stool in the alimentary tract. As the position of the pancreas changes depending on the body posture, and several different body positions should be employed, such as the right lateral decubitus, sitting, and upright positions, rather than only applying strong compression with the transducer. In cases with poor visualization, the liquid-filled stomach method is highly recommended.

Imaging diagnosis and staging of pancreatic ductal adenocarcinoma: a comprehensive review

Pancreatic ductal adenocarcinoma (PDAC) has continued to have a poor prognosis for the last few decades in spite of recent advances in different imaging modalities mainly due to difficulty in early diagnosis and aggressive biological behavior. Early PDAC can be missed on CT due to similar attenuation relative to the normal pancreas, small size, or hidden location in the uncinate process. Tumor resectability and its contingency on the vascular invasion most commonly assessed with multi-phasic thin-slice CT is a continuously changing concept, particularly in the era of frequent neoadjuvant therapy. Coexistent celiac artery stenosis may affect the surgical plan in patients undergoing pancreaticoduodenectomy. In this review, we discuss the challenges related to the imaging of PDAC. These include radiological and clinical subtleties of the tumor, evolving imaging criteria for tumor resectability, preoperative diagnosis of accompanying celiac artery stenosis, and post-neoadjuvant therapy imaging. For each category, the key imaging features and potential pitfalls on cross-sectional imaging will be discussed. Also, we will describe the imaging discriminators of potential mimickers of PDAC.

Chronic Pancreatitis or Pancreatic Tumor? A Problem-solving Approach

Certain inflammatory pancreatic abnormalities may mimic pancreatic ductal adenocarcinoma at imaging, which precludes accurate preoperative diagnosis and may lead to unnecessary surgery. Inflammatory conditions that may appear masslike include mass-forming chronic pancreatitis, focal autoimmune pancreatitis, and paraduodenal pancreatitis or "groove pancreatitis." In addition, obstructive chronic pancreatitis can mimic an obstructing ampullary mass or main duct intraductal papillary mucinous neoplasm. Secondary imaging features such as the duct-penetrating sign, biliary or main pancreatic duct skip strictures, a capsulelike rim, the pancreatic duct-to-parenchyma ratio, displaced calcifications in patients with chronic calcific pancreatitis, the "double duct" sign, and vessel encasement or displacement can help to suggest the possibility of an inflammatory mass or a neoplastic process. An awareness of the secondary signs that favor a diagnosis of malignant or inflammatory lesions in the pancreas can help the radiologist to perform the differential diagnosis and determine the degree of suspicion for malignancy. Repeat biopsy or surgical resection may be necessary to achieve an accurate diagnosis and prevent unnecessary surgery for inflammatory conditions. Online supplemental material and DICOM image stacks are available for this article. ^©RSNA, 2019.

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.

Pancreaticoduodenectomy and Outcomes for Groove Pancreatitis

BACKGROUND/AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

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.

Pancreatic groove cancer

Pancreatic groove cancer is very rare and can be indistinguishable from groove pancreatitis. This study is to clarify the characteristics, clinical features, managements, and survival outcomes of this rare tumor.Brief descriptions were made for each case of pancreatic groove cancer encountered at our institute. Individualized data of pancreatic groove cancer cases described in the literature were extracted and added to our database to expand the study sample size for a more complete analysis.A total of 33 patients with pancreatic groove cancer were included for analysis, including 4 cases from our institute. The median tumor size was 2.7 cm. The most common symptom was nausea or vomiting (89%), followed by jaundice (67%). Duodenal stenosis was noted by endoscopy in 96% of patients. The histopathological examination revealed well differentiated tumor in 43%. Perineural invasion was noted in 90%, and lymphovascular invasion and lymph node involvement in 83%. Overall 1-year survival rate was 93.3%, and 3- or 5-year survival rate was 62.2%, with a median survival of 11.0 months. Survival outcome for the well-differentiated tumors was better than those of the moderate/poorly differentiated ones.Early involvement of duodenum causing vomiting is often the initial presentation, but obstructive jaundice does not always happen until the disease progresses. Tumor differentiation is a prognostic factor for survival outcome. The possibility of pancreatic groove cancer should be carefully excluded before making the diagnosis of groove pancreatitis for any questionable case.

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.

Well differentiation and intact Smad4 expression are specific features of groove pancreatic ductal adenocarcinomas

OBJECTIVES

We aimed to select true groove pancreatic ductal adenocarcinomas (GPDACs) and define their specific features.

METHODS

We performed histopathologic and immunohistochemical comparisons of 6 GPDACs with 6 duodenal adenocarcinomas (DACs) and 24 conventional pancreatic ductal adenocarcinomas (cPDACs). Both groups were adjusted to ensure similar mean tumor size.

RESULTS

Representative loupe image showed prominent duodenal invasion and slight pancreatic invasion. Groove pancreatic ductal adenocarcinomas exhibited different mucins and cytokeratin profiles in DACs, but cPDACs and small branch pancreatic ducts had the same profiles. Histopathologic analysis of GPDACs showed a significantly higher incidence of duodenal invasion and well differentiation than cPDACs, although the incidences of lymph node metastasis, angiolymphatic invasion, and neural invasion were similar. Immunohistochemical analysis of GPDACs showed a significantly lower frequency of abnormal Smad4 immunolabeling, and fewer GPDAC samples exhibited abnormal immunolabeling for MUC1, p16, Smad4, and p53 than cPDACs.

CONCLUSIONS

These results suggest that GPDACs arise from small branch pancreatic ducts around accessory pancreatic duct penetrating the groove and duodenum and are distinguishable from DACs. Molecular immunohistochemistry suggests the accumulation of genetic abnormalities during tumor progression is slow in comparison with cPDACs. Thus, the site of PDAC occurrence, such as the border or inner area of the pancreas head, may determine genetic progressivity.

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.

Dual-phase CT findings of groove pancreatitis

PURPOSE

Groove pancreatitis is a rare focal form of chronic pancreatitis that occurs in the pancreaticoduodenal groove between the major and minor papillae, duodenum and pancreatic head. Radiologic appearance and clinical presentation can result in suspicion of malignancy rendering pancreaticoduodenectomy inevitable. This study reports dual phase CT findings in a series of 12 patients with pathology proven groove pancreatitis.

MATERIALS AND METHODS

Retrospective review of preoperative CT findings in 12 patients with histologically proven groove pancreatitis after pancreaticoduodenectomy. Size, location, attenuation, presence of mass or cystic components in the pancreas, groove and duodenum, calcifications, duodenal stenosis and ductal changes were recorded. Clinical data, laboratory values, endoscopic ultrasonographic and histopathological findings were collected.

RESULTS

Soft tissue thickening in the groove was seen in all patients. Pancreatic head, groove and duodenum were all involved in 75% patients. A discrete lesion in the pancreatic head was seen in half of the patients, most of which appeared hypodense on both arterial and venous phases. Cystic changes in pancreatic head were seen in 75% patients. Duodenal involvement was seen in 92% patients including wall thickening and cyst formation. The main pancreatic duct was dilated in 7 patients, with an abrupt cut off in 3 and a smooth tapering stricture in 4. Five patients had evidence of chronic pancreatitis with parenchymal calcifications.

CONCLUSION

Presence of mass or soft tissue thickening in the groove with cystic duodenal thickening is highly suggestive of groove pancreatitis. Recognizing common radiological features may help in diagnosis and reduce suspicion of malignancy.

Groove Pancreatitis: Four Cases from a Single Center and Brief Review of the Literature

Groove pancreatitis is a rare form of chronic pancreatitis that affects the groove anatomical area between the head of the pancreas, duodenum, and common bile duct. We provide a summary of the clinical findings of 4 groove pancreatitis cases diagnosed at a tertiary academic medical center over a 5-year period. A detailed review of the current literature surrounding this clinical entity is also provided. Although rare, groove pancreatitis should be considered in the differential diagnosis of patients presenting with pancreatic head mass lesions, as appropriate diagnosis can help avoid unnecessary surgical procedures.

Duodenum: MDCT of acute conditions

Multidetector computed tomography (MDCT) is the technique of choice for evaluating patients with acute abdominal pain. As the jejunum, ileum, and colon comprise the majority of the gastrointestinal tract, radiologists may potentially neglect the duodenum. However, the duodenum is a complex structure that can be affected by both intraperitoneal and extraperitoneal processes due to its central location and proximity to numerous upper abdominal structures. In this review, the MDCT findings of various congenital, inflammatory, traumatic, infectious, vascular, and miscellaneous conditions that affect the duodenum are discussed.

A solid pancreatic mass: tumour or inflammation?

The prognosis for pancreatic cancer is poor, and early diagnosis is essential for surgical management. By comparison with its classic form, the presence of acute or chronic inflammatory signs will hinder its detection and delay its diagnosis. The atypical forms of acute pancreatitis need to be known in order to detect patients who require additional morphological investigations to search for an underlying tumour. In contrast, pseudotumoral forms of inflammation (chronic pancreatitis, cystic dystrophy in heterotopic pancreas, autoimmune pancreatitis) may simulate a cancer, and make up 5-10% of the surgical procedures for suspected cancer. Faced with these pseudotumoral masses, interpretation relies on various differentiating signs and advances in imaging.

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.

Part 2: CT characterisation of pancreatic neoplasm: tumour mimics

There are numerous pancreatic and peripancreatic conditions that can mimic pancreatic neoplasms. Many of these can be confidently diagnosed on computed tomography (CT), while others will require further imaging. Knowledge of these tumour mimics is important to avoid misclassification of benign conditions as malignant and to avoid unnecessary surgery. Mimics can be grouped as parenchymal, vascular, biliary and peripancreatic. These are discussed and illustrated in this review.

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.

"Paraduodenal" pancreatitis: results of surgery on 58 consecutives patients from a single institution

BACKGROUND

Cystic dystrophy of heterotopic pancreas, groove pancreatitis, pancreatic hamartoma of the duodenum, paraduodenal wall cyst, and myoadenomatosis are all terms grouped together, from a pathological viewpoint, as definitions of paraduodenal pancreatitis (PP). The objective of the present study was to investigate the clinical characteristics, therapeutic strategies, and results in 58 patients undergoing pancreatic resection for PP.

METHODS

From January 1990 to December 2006 data were prospectively collected on 58 patients who were diagnosed with PP who then underwent pancreaticoduodenectomy.

RESULTS

In this patient cohort the median age was 44.7 years; only 4 patients were women, and only 3 had non-drinker and/or non smoker habits. The overall morbidity was 18.9%, and the median hospitalization was 11 days. There were no postoperative deaths. In a median follow-up of 96.3 months, all patients noted a decrease in the pain associated with PP; 35 patients (76%) had complete disappearance of pain, whereas occasional relapsing pain occurred in the remaining 11 (24%).

CONCLUSIONS

Patients with PP have clinical characteristics similar to those of chronic pancreatitis. The diagnostic imaging modalities of choice are ultrasonographic endoscopy and magnetic resonance cholangiopancreaticography. Based on our surgical experience, pancreaticoduodenectomy seems to be a reasonable choice of treatment in patients with PP.

A clinical and radiologic review of uncommon types and causes of pancreatitis

Acute pancreatitis is one of the most common conditions for which emergent imaging is indicated. Alcohol consumption and cholelithiasis are the most common causes of acute pancreatitis in adults, whereas the majority of cases in children are idiopathic or secondary to trauma. A wide variety of structural and biochemical abnormalities may also cause pancreatitis. Although in some cases it is difficult to identify the specific cause of the disease radiologically, certain uncommon types of acute or chronic pancreatitis may have unique imaging features that can help the radiologist make an accurate diagnosis. These unusual types include autoimmune pancreatitis, groove pancreatitis, tropical pancreatitis, hereditary pancreatitis, and pancreatitis in ectopic or heterotopic pancreatic tissue. Pancreatitis may occasionally be seen in association with cystic fibrosis or pancreas divisum, or secondary to worm infestation of the pancreaticobiliary tree (eg, by Ascaris lumbricoides). In addition, primary pancreatic and duodenal masses may occasionally manifest as acute or recurrent acute pancreatitis. Knowledge of the classic imaging findings of these entities allows prompt recognition of the relevant pathologic condition, thereby preventing misdiagnosis and subsequent inappropriate or delayed 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.

Differential diagnosis of groove pancreatic carcinomas vs. groove pancreatitis: usefulness of the portal venous phase

PURPOSE

To clarify if the portal venous phase is helpful for the differential diagnosis of groove pancreatic carcinomas and groove pancreatitis.

MATERIALS AND METHODS

MDCT and MRI of groove pancreatic carcinomas (n=7) and groove pancreatitis (n=15) were retrospectively reviewed by two radiologists independently. The signal intensity on T2-weighted images was subjectively assessed. The presence or absence of common bile duct (CBD) and main pancreatic duct (MPD) strictures, calcifications, and cystic lesions was evaluated. Additionally, the appearance of groove pancreatic carcinoma and that of groove pancreatitis in the portal venous phase on dynamic MDCT and MRI were compared.

RESULTS

There were no significant differences in the signal intensity on T2-weighted images and in the presence or absence of CBD and MPD strictures, calcifications, and cystic lesions between groove pancreatic carcinomas and groove pancreatitis. However, patchy focal enhancement in the portal venous phase was more commonly observed in groove pancreatitis than groove pancreatic carcinoma (Reviewers 1 and 2: 14/15 [93.3%] vs. 1/7 [14.3%], P<0.0001). In addition, peripheral enhancement was only seen in groove pancreatic carcinomas (Reviewer 1: 4/7 [57.1%] vs. 0/15 [0%], P<0.005, and Reviewer 2: 3/7 [42.9%] vs. 0/15 [0%], P<0.05).

CONCLUSION

The portal venous phase may be helpful for the differential diagnosis of groove pancreatic carcinomas and groove pancreatitis.

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.

Uncommon tumors and pseudotumoral lesions of the pancreas

Ductal adenocarcinoma is the most common tumor of the pancreas, accounting for about 80% of all pancreatic tumors. The other 20% of pancreatic tumors is represented by a heterogeneous group of pancreatic neoplasms that includes cystic pancreatic neoplasms, islet cell tumors, and the so-called rare pancreatic tumors. In addition, the pancreatic gland may present a variety of inflammatory and pseudotumoral lesions that may mimic a primary pancreatic neoplasm. These uncommon tumors and pseudotumoral lesions present a wide spectrum of imaging findings and they are often poorly understood by the radiologist, becoming a diagnostic challenge. Some of these lesions may show an appearance similar to ductal adenocarcinoma being radiologically indistinguishable. However, some of these lesions sometimes may present specific features on imaging studies that may help to characterize the mass and to suggest a correct diagnosis. Many of these uncommon tumors and pseudotumoral lesions have a different approach, therapy, and prognosis than ductal adenocarcinoma. Therefore, it is important for the radiologist to be familiar with these entities to include them in the differential diagnosis to initiate an appropriate lesion-specific workup and treatment. In the present article, we review the radiological features of uncommon pancreatic tumors, atypical manifestations of ductal adenocarcinoma, and pseudotumoral masses, focusing on those features that can be helpful for the differential diagnosis.

Groove pancreatitis: MRI and pathologic findings

OBJECTIVE

Our purpose is to describe the MRI findings with pathologic correlation, in five patients with groove pancreatitis, a specific form of chronic pancreatitis affecting the groove between the pancreatic head, the common bile duct and duodenum.

MATERIALS AND METHODS

Five patients with pathologically proven (four cases) and clinical and MRI findings (follow-up) consistent with the diagnosis of groove pancreatitis (one case) were reviewed. Three patients underwent cephalic pancreatoduodenectomy (Whipple procedure) due to severe duodenal stenosis; MRI findings were correlated with the histological findings.

RESULTS

In all patients a mass was seen affecting the groove between the pancreatic head and the duodenum. Precontrast images demonstrated hypointense tissue relative to pancreatic parenchyma on T1-weighted images and iso to slightly hyperintense tissue on STIR and T2-weighted images. Postcontrast dynamic Gd-DTPA images, showed peripheral mass enhancement on immediate postgadolinium images and progressive and centripetal mass enhancement on delayed images with good delineation of multiple cysts. Histologically, fibro-inflammatory tissue was demonstrated in the groove and the duodenal wall with obliterative concentric scarring of the distal common bile duct.

CONCLUSIONS

MRI findings are demonstrative of the pathologic features characteristic of this entity: the fibrous tissue in the pancreaticoduodenal groove, the duodenal wall inflammation and the groove and/or duodenal wall cyst formation.

Evaluation of unusual causes of pancreatitis: role of cross-sectional imaging

There are widely diverse causes of pancreatitis. Gallstone and alcohol have been recognized as the most common causes of pancreatitis accounting for 90% of cases. However, acute and chronic pancreatitis may also result from a variety of uncommon causes. The determination of the etiology is important for patient management and prevention of recurrence. Sludge is the most common cause of idiopathic or recurrent acute pancreatitis. Endoscopic ultrasonography is considered as the most accurate diagnostic test for this abnormality. Computed tomography (CT) and magnetic resonance imaging (MRI) have only a limited role in the diagnosis of sludge. However, papillitis observed on the contrast-enhanced CT and MR may provide clues to the detection of pancreatitis secondary to sludge, a small stone or a recently passed stone. Radiological studies, clinical presentation and laboratory data can be helpful in determining the etiology of unusual causes of pancreatitis such as anatomic anomalies, autoimmune pancreatitis, groove pancreatitis, and traumatic pancreatitis.

Groove pancreatitis associated with true pancreatic cyst

We report a case of groove pancreatitis (GP) associated with a true pancreatic cyst. An 81-year-old man who had suffered epigastric pain for 4 months was referred to Saisekai Kure Hospital. Computed tomography and endoscopic retrograde pancreatography showed a cystic lesion in the groove area of the pancreas. Serum amylase elevation and imaging findings suggested GP due to the cyst. Six weeks of medical treatment did not improve the clinical symptoms. Therefore, pancreatoduodenectomy was performed. Histologic examination revealed a true cyst with intraluminal necrosis, which produced a protein plug that obstructed the Santorini duct. The parenchyma surrounding the groove area showed marked fibrosis and inflammatory cell infiltration. GP due to true pancreatic cyst was diagnosed. Although GP is usually caused by overconsumption of alcohol, which leads to changes in the pancreatic juice and the ultimate blockage of pancreatic outflow, the histologic features in our patient suggest that true pancreatic cyst stands as a secondary cause of GP.