Lesions of the pancreaticoduodenal groove, a pictorial review

Transcription

1 Lesions of the pancreaticoduodenal groove, a pictorial review Poster No.: C-2131 Congress: ECR 2013 Type: Educational Exhibit Authors: E. Ni Mhurchu, L. Lavelle, I. Murphy, S. Skehan ; IE, Dublin/ IE Keywords: Pathology, Diagnostic procedure, MR, CT, Pancreas, Abdomen DOI: /ecr2013/C Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. Page 1 of 25

2 Learning objectives 1. Identify the anatomic potential space, the pancreaticoduodenal (PD) groove. 2. Discuss and classify the range of pathological conditions that can present with imaging abnormalities in the region. 3. Describe, with illustrated examples, a range of cases encountered in our clinical practice. Background The PD groove is a potential space which is bordered anteriorly by the first part of the duodenum, laterally by the second part and posteriorly by the third part of the duodenum or inferior vena cava. It is bordered medially by the head of the pancreas Fig. 1 on page 2 and Fig. 2 on page 3. The common bile duct traverses it, and it contains fat and some small lymph nodes. Images for this section: Page 2 of 25

3 Fig. 1: The anatomic location and appearance of a normal pancreatico-duodenal (PD) groove on axial CT. D=duodemun, P=pancreas, I=IVC. Page 3 of 25

4 Fig. 2: The normal appearance of the PD groove on axial T2 MRI. Page 4 of 25

5 Imaging findings OR Procedure details Diseases of the PD groove can be classified by their origin, relating to the surrounding structures. Disease processes of the pancreas, duodenum, lymph nodes, common bile duct and disease processes extending into the groove from elsewhere. 1.Pancreas Acute pancreatitis, Fig. 3 on page 6 Acute pancreatitis involving the PD groove is different from groove pancreatitis. It is characterised by inflammatory change and fluid in the PD groove that changes over time. The remainder of the pancreas is normal in appearance. Groove pancreatitis Fig. 4 on page 7, Fig. 5 on page 8, Fig. 6 on page 9 Groove pancreatitis is a form of chronic segmental pancreatitis affecting the groove in the region of the pancreatic head, duodenum, and common bile duct. The aetiology remains unclear, but it may relate to peptic ulcers, duodenal wall cysts and gastric resection. A soft tissue mass is noticed in the PD groove which has been shown to consist of fibrous scar. There is late enhancement of this scar on imaging. Cystic dystrophy of the duodenal wall is associated, with thickening of the wall of the duodenum and cysts within it. Pancreatic adenocarcinoma Fig. 7 on page 10, Fig. 8 on page 11, Fig. 9 on page 12 Pancreatic adenocarcinoma can occasionally present as an exophytic lesion extending into the PD groove. The mass is inseparable from the pancreatic head, may cause biliary duct dilatation and there may be adjacent vascular invasion. Neuro-endocrine tumour Fig. 10 on page 13 This tumour can also present as a hyperenhancing mass in the PD groove. Features that can aid diagnosis are the hyperenhancement of the lesion as well as the presence of hypervascular liver metastases. 2.Duodenum Diverticulum Fig. 11 on page 14, Fig. 12 on page 15 Page 5 of 25

6 A diverticulum of the second or third part of the duodenum can present as a mass in the PD groove. It is important to distinguish as it may mimic lesions such as a pseudocyst or abscess. A diverticulum could also become impacted and present as duodenal diverticulitis. 3. Lymph nodesfig. 13 on page 16, Fig. 14 on page 17, Fig. 15 on page 18, Fig. 16 on page 19, Fig. 17 on page 20 Lymph nodes in the PD groove drain the liver, biliary tract, duodenum and pancreas. Enlarged nodes in this location may represent infection, lymphoma or metastases. Enlarged nodes elsewhere can be a clue to the diagnosis of lymphoma. An enlarged node can sometimes be difficult to distinguish from a primary lesion of the pancreas. 4. Common Bile Duct Cholangiocarcinoma A cholangiocarcinoma extending into the PD groove should have associated intra- and extra-hepatic biliary duct dilatation terminating at the level of the lesion. Choledochal cyst This may mimic fluid in the PD groove. MRCP can help to establish a communication between the lesion in the PD groove and the common bile duct. 5. Invasion from elsewhere Lymphangioma Fig. 18 on page 21, Fig. 19 on page 22, Fig. 20 on page 23 In theory, adjacent disease processes may invade the PD groove. Fig show a benign retroperitoneal haemangioma, which involves the PD groove. It is characterised by water signal fluid and is soft, being easily indented by its surrounding structures. Images for this section: Page 6 of 25

7 Fig. 3: Acute pancreatitis of the PD groove on axial contrast enhanced CT, showing fat stranding and inflammatory change in the PD groove. The remainder of the pancreas is normal in appearance (curved arrow). Page 7 of 25

8 Fig. 4: Coronal CT. Showing a cyst within the wall of the duodenum in a case of groove pancreatitis Page 8 of 25

9 Fig. 5: Axial CT showing low attenuation ill-defined mass in the PD groove consistent with groove pancreatitis. Page 9 of 25

10 Fig. 6: Axial CT. Duodenal cyst in the PD groove Page 10 of 25

11 Fig. 7: Axial CT showing soft tissue attenuation mass extending into the PD groove from the head of the pancreas. This was also causing intra-hepatic duct dilatation (fig 8). Biopsy showed pancreatic adenocarcinoma Page 11 of 25

12 Fig. 8: Axial CT showing biliary obstruction with PD groove adenocarcinoma from fig 7 Page 12 of 25

13 Fig. 9: Axial CT showing ancreatic adenocarcinoma in the PD groove and dilatation of the gallbladder. Page 13 of 25

14 Fig. 10: Axial CT.Low attenuation mass in the PD groove on portal venous phase. Biopsy showed neuroendocrine tumor. Page 14 of 25

15 Fig. 11: Axial CT showing air and fluid filled structure in the PD groove consistent with a duodenal diverticulum. Page 15 of 25

16 Fig. 12: Axial CT on the same patient as fig 11 shows communication with the duodenum, confirming a diverticulum. Page 16 of 25

17 Fig. 13: Axial CT shows well circumscribed mass in the PD groove, displacing the duodenum and pancreas.there is also retroperitoneal lymphadenopathy fig 14, biopsy of which revealed lymphoma Page 17 of 25

18 Fig. 14: Axial CT Fig 13 shows well circumscribed mass in the PD groove, displacing the duodenum and pancreas.this image shows retroperitoneal lymphadenopathy, biopsy of which revealed lymphoma Page 18 of 25

19 Fig. 15: Fig 15, 16 and 17. Axial CT showing a low attenuation mass in the PD groove with a left retroperitoneal nodule and right atrial mass. Biopsy of the retroperitoneal mass showed lymphoma. Page 19 of 25

20 Fig. 16: Fig 15, 16 and 17. Axial CT showing a low attenuation mass in the PD groove with a left retroperitoneal nodule and right atrial mass. Biopsy of the retroperitoneal mass showed lymphoma. Page 20 of 25

21 Fig. 17: Fig 15, 16 and 17. Axial CT showing a low attenuation mass in the PD groove with a left retroperitoneal nodule and right atrial mass. Biopsy of the retroperitoneal mass showed lymphoma. Page 21 of 25

22 Fig. 18: T2 axial MRI showing a fluid signal encapsulated mass in the right retroperitoneum extending into the PD groove. Also seen in the same patient in fig 19 and 20. Page 22 of 25

23 Fig. 19: Axial CT shows a water density mass in the right retroperitoneum posterior to the PD groove. Th patient had complete surgical excision of a lymphgangioma. Also seen in the PD groove in fig 18. Page 23 of 25

24 Fig. 20: Coronal T2 MRI showing fluid signal mass in the right retroperitoneum, which was a lymphangioma extending into the PD groove, seen in fig 18 and 19. Page 24 of 25

25 Conclusion The PD groove is a potential space, which can contain pathology from its surrounding structures or invasion from elsewhere. This exhibit has classified these differentials and provides, with illustrated examples, a framework for distinguishing between them. References Yu J, Fulcher AS, Turner MA, Halvorsen RA. Normal anatomy and disease processes of the pancreatoduodenal groove: imaging features. AJR Am J Roentgenol. 2004;183: Irie H, Honda H, Kuroiwa T, et al. MRI of groove pancreatitis. J Comput Assist Tomogr1998 ;22: Itoh S, Yamakawa K, Shimamoto K, Endo T, Ishigaki T. CT findings in groove pancreatitis: correlation with histopathological findings. J Comput Assist Tomogr 1994;18: Stolte M, Weiss W, Volkholz H, Rosch W. A special form of segmental pancreatitis: groove pancreatitis. Personal Information Page 25 of 25