Groove Pancreatitis

Published on 19/07/2015 by admin

Filed under Radiology

Last modified 22/04/2025

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 Pure form: Affects only pancreaticoduodenal groove

image Segmental form: Affects pancreaticoduodenal groove and extends medially into pancreatic head
• Pancreatic groove is a theoretical space defined by pancreatic head (medially), 2nd portion of duodenum (laterally), 3rd portion of duodenum and IVC (posteriorly), and duodenal bulb (superiorly)

IMAGING

• Sheet-like, curvilinear soft tissue mass between pancreatic head and duodenum

image May demonstrate delayed enhancement
image MR: Usually T1 hypointense with variable T2 signal (depending on acuity)
• Thickened medial duodenal wall ± cysts within groove or thickened duodenal wall
• Segmental form: Mass-like enlargement of pancreatic head
• Calcifications and ductal dilatation/beading can develop in chronic setting (similar to traditional chronic pancreatitis)

TOP DIFFERENTIAL DIAGNOSES

• Pancreatic ductal adenocarcinoma
• Duodenal carcinoma
• Acute edematous pancreatitis involving groove

CLINICAL ISSUES

• Usually middle-aged men with history of alcohol abuse
• Acute setting: Postprandial abdominal pain, vomiting, or acute gastric outlet obstruction
• Chronic setting: Chronic weight loss, jaundice
• Amylase, lipase, and tumor markers are usually normal
• Prospective diagnosis is very uncommon; difficult to exclude malignancy with imaging or biopsy
• Surgery (Whipple procedure) may be required to rule out malignancy or due to intractable symptoms
image
(Left) Gross photo of a pancreaticoduodenectomy specimen shows a mass-like lesion image beneath the duodenal mucosa, representing groove pancreatitis. Note the paraduodenal zone of fibrosis with numerous small cysts image.

image
(Right) Axial CECT shows subtle soft tissue thickening image in the pancreaticoduodenal groove, as well as mass-like pancreatic head image enlargement with an internal cyst image. This was found to be segmental (given pancreatic head involvement) groove pancreatitis at surgery.
image
(Left) Axial CECT image demonstrates a hypodense soft tissue mass image in the pancreaticoduodenal groove with associated cystic spaces image, resulting in upstream pancreatic ductal dilatation image.

image
(Right) Coronal volume-rendered CECT image nicely demonstrates the hypodense soft tissue image in the pancreaticoduodenal groove with associated cystic spaces image. Initially suspected to represent malignancy, this was found to be groove pancreatitis at surgery.

TERMINOLOGY

Synonyms

• Cystic dystrophy of duodenal wall, pancreatic hamartoma of duodenal wall, periampullary duodenal wall cyst

Definitions

• Form of chronic pancreatitis affecting pancreaticoduodenal groove

image Pure form: Affects only pancreaticoduodenal groove
image Segmental form: Affects pancreaticoduodenal groove and extends medially into pancreatic head
• Pancreatic groove is a theoretical space defined by pancreatic head (medially), 2nd portion of duodenum (laterally), 3rd portion of duodenum and IVC (posteriorly), and duodenal bulb (superiorly)

image Contains distal common bile duct (CBD), main/accessory pancreatic ducts, and major/minor papilla

IMAGING

General Features

• Best diagnostic clue

image Curvilinear soft tissue between pancreas and duodenum

CT Findings

• Sheet-like, curvilinear soft tissue mass (with delayed enhancement) between pancreatic head and duodenum
• Thickened medial duodenal wall ± cysts (within pancreatic groove, duodenal wall, or pancreatic head)
• Narrowing of distal CBD and pancreatic duct at ampulla
• Absence of retroperitoneal inflammation or fluid
• Segmental form: Mass-like enlargement of pancreatic head
• Calcifications and ductal beading in chronic setting

MR Findings

• Sheet-like groove thickening is mildly T1 hypointense
• Variable T2 signal (depending on acuity): T2 hyperintense in acute phase and hypointense chronically

image T2 hyperintense cysts in medial duodenal wall or groove
• Pancreatic head may be enlarged with low T1 signal in segmental form (due to fibrosis/atrophy)
• T1WI C+: Delayed enhancement of affected areas
• MRCP: Smooth narrowing of distal CBD and pancreatic duct with widened space between ampulla and duodenal lumen

Ultrasonographic Findings

• Acute setting: Hypoechoic band-like thickening in groove (with hypoechoic, heterogeneous pancreatic head in segmental form)
• Chronic setting: Hyperechoic band-like thickening in groove (with hyperechoic pancreatic head in segmental form)

Imaging Recommendations

• Best imaging tool

image CECT or MR with MRCP

DIFFERENTIAL DIAGNOSIS

Pancreatic Ductal Adenocarcinoma

• Infiltrative hypodense mass with upstream pancreatic atrophy and pancreatic ductal dilatation
• May be centered in close proximity to groove and appear indistinguishable from groove pancreatitis
• Thickening of duodenal wall or cystic change is uncommon

Duodenal Carcinoma

• Mass centered in duodenum (not in pancreatic groove) without cystic change

Acute Edematous Pancreatitis Involving Groove

• Not primarily centered in pancreaticoduodenal groove and usually involves entire pancreas
• Associated with peripancreatic inflammation, including retroperitoneal fluid and fat stranding
• Should resolve on follow-up examinations

PATHOLOGY

General Features

• Etiology

image Exact cause unknown, although there are multiple theories

– Alcohol consumption or smoking → increased viscosity of pancreatic juice → occlusion of minor papilla
– Functional obstruction of minor papilla/Santorini duct
– Heterotopic pancreas in duodenal wall
– Peptic ulcer disease and Brunner gland hyperplasia

Gross Pathologic & Surgical Features

• Fibrotic mass-like thickening in pancreaticoduodenal groove and stenosis of terminal CBD
• Involved areas can have internal cysts (± internal calculi)

Microscopic Features

• Thickening of duodenal wall and adjacent pancreas
• Brunner gland and smooth muscle hyperplasia
• Chronic pancreatitis ± calcification

CLINICAL ISSUES

Presentation

• Most common signs/symptoms

image Acute setting: Postprandial abdominal pain, nausea, and vomiting
image Chronic setting: Chronic weight loss, jaundice
image Amylase, lipase, and tumor markers usually normal
• Other signs/symptoms

Demographics

• Often middle-aged men with history of alcohol abuse

Natural History & Prognosis

• May progress to generalized chronic pancreatitis

Treatment

• Prospective diagnosis is very uncommon; difficult (or impossible) to exclude malignancy with imaging or biopsy
• Surgery (Whipple procedure) may be required to rule out malignancy or due to intractable symptoms
• Fasting, parenteral nutrition, and cessation of smoking/alcohol if prospective diagnosis is made
image
(Left) Axial CECT demonstrates subtle stranding and induration image in the pancreaticoduodenal groove, which persisted on follow-up examinations.

image
(Right) Axial CECT image from the same patient again demonstrates induration image in the pancreaticoduodenal groove. Initially suspected to represent a duodenal malignancy, this was found to be groove pancreatitis at surgery.
image
(Left) Axial CECT shows focal soft tissue thickening image in the pancreaticoduodenal groove, which persisted over multiple follow-up studies. There is also some fluid image tracking from the groove into the right anterior pararenal space.

image
(Right) Axial CECT in the same patient shows thickening image in the groove, with several cysts image present in the pancreatic head. This was found to be groove pancreatitis at surgery, but the presence of fluid tracking in the retroperitoneum is atypical and more common with acute edematous pancreatitis.
image
(Left) Axial CECT demonstrates focal soft tissue thickening image in the pancreaticoduodenal groove with multiple internal cystic spaces image.

image
(Right) Coronal volume-rendered CECT from the same patient again demonstrates focal soft tissue thickening image in the pancreaticoduodenal groove with multiple internal cystic spaces image. While this was suspected to represent groove pancreatitis, Whipple procedure was performed to exclude underlying malignancy, a common outcome in these cases.
image
(Left) Axial CECT shows a markedly distended stomach and proximal duodenum image secondary to gastric outlet obstruction. Note the band-like soft tissue thickening image in the groove between the 2nd duodenum and the pancreas, characteristic of groove pancreatitis.

image
(Right) More caudal CECT from the same patient shows that the lumen of the 2nd portion of duodenum image is markedly narrowed by the adjacent soft tissue, and there is a small cyst image in the pancreatic groove.
image
(Left) Axial CECT shows thickening of the medial wall of the duodenum, luminal narrowing, and 2 small cysts image. This was found to represent groove pancreatitis at surgery.

image
(Right) Axial CECT image demonstrates a fibroinflammatory mass with calcifications image centered in the groove. Groove pancreatitis in the chronic setting, as in this case, can appear very similar to traditional chronic pancreatitis (including the presence of calcifications).
image
(Left) Axial CECT shows low-attenuation soft tissue thickening in the groove between the head of the pancreas and the 2nd duodenum image. Note the stent image in the common duct placed due to biliary obstruction from the adjacent soft tissue.

image
(Right) Axial volume-rendered CECT shows that the hypodense soft tissue encases the gastroduodenal artery image and thickens the medial wall of the 2nd duodenum image.

SELECTED REFERENCES

1. Raman, SP, et al. Groove pancreatitis: spectrum of imaging findings and radiology-pathology correlation. AJR Am J Roentgenol. 2013; 201(1):W29–W39.

 

Gupta, R, et al. Groove pancreatitis: a common condition that is uncommonly diagnosed preoperatively. Can J Gastroenterol Hepatol. 2014; 28(4):181–182.

Kim, JD, et al. Characteristic clinical and pathologic features for preoperative diagnosed groove pancreatitis. J Korean Surg Soc. 2011; 80(5):342–347.

Malde, DJ, et al. Pancreatic carcinoma masquerading as groove pancreatitis: case report and review of literature. JOP. 2011; 12(6):598–602.

Manzelli, A, et al. Groove pancreatitis. A mini-series report and review of the literature. JOP. 2011; 12(3):230–233.

Wronski, M, et al. Sonographic findings in groove pancreatitis. J Ultrasound Med. 2011; 30(1):111–115.

Blasbalg, R, et al. MRI features of groove pancreatitis. AJR Am J Roentgenol. 2007; 189(1):73–80.

Chatelain, D, et al. Groove pancreatitis and pancreatic heterotopia in the minor duodenal papilla. Pancreas. 2005; 30(4):e92–e95.

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