DOI: 10.1148/rg.254045167
Pancreatic and Peripancreatic Diseases Mimicking Primary Pancreatic Neoplasia1
Katherine J. To’o, BS,
Steven S. Raman, MD,
Nam C. Yu, MD,
Young Jun Kim, MD2,
Tyler Crawford, MD,
Barbara M. Kadell, MD and
David S. K. Lu, MD
1 From the Department of Radiology, David Geffen School of Medicine at UCLA, 10833 Le Conte Ave, BL-428 CHS, Box 951721, UCLA Medical Center, Los Angeles, CA 90095-1721. Presented as an education exhibit at the 2003 RSNA Annual Meeting. Received August 26, 2004; revision requested September 23 and received November 19; accepted November 23. All authors have no financial relationships to disclose.
View larger version (133K):
[in a new window]
|
Figure 1a. Normal unenhanced duodenum mimicking a pancreatic mass. (a) CT scan shows findings that suggest enlargement of the head of the pancreas (*). (b) Repeat CT scan obtained with additional oral contrast material shows a normal pancreatic head, with contrast material in the duodenum (arrow) and gallbladder (*).
|
|
View larger version (131K):
[in a new window]
|
Figure 1b. Normal unenhanced duodenum mimicking a pancreatic mass. (a) CT scan shows findings that suggest enlargement of the head of the pancreas (*). (b) Repeat CT scan obtained with additional oral contrast material shows a normal pancreatic head, with contrast material in the duodenum (arrow) and gallbladder (*).
|
|
View larger version (118K):
[in a new window]
|
Figure 2. Chronic pancreatitis following a Puestow procedure. CT scan shows anastomosis of a dilated pancreatic duct with a jejunal limb mimicking a cystic pancreatic mass (arrow).
|
|
View larger version (139K):
[in a new window]
|
Figure 3a. Annular pancreas. (a) CT scan shows pancreatic tissue encircling the duodenum (*). (b) ERCP image shows the main pancreatic duct wrapped around the endoscope (arrows). In addition, the annular pancreas causes stenosis of the common bile duct, which is distended proximally (arrowhead).
|
|
View larger version (131K):
[in a new window]
|
Figure 3b. Annular pancreas. (a) CT scan shows pancreatic tissue encircling the duodenum (*). (b) ERCP image shows the main pancreatic duct wrapped around the endoscope (arrows). In addition, the annular pancreas causes stenosis of the common bile duct, which is distended proximally (arrowhead).
|
|
View larger version (122K):
[in a new window]
|
Figure 4a. Duodenal duplication. (a) CT scan shows a fluid-filled, circumferential duodenal duplication, which may be mistaken for a pancreatic mass on axial sections. (b) Coronal multiplanar reformatted image demonstrates the full extent of the duodenal duplication (*) adjacent to the pancreas (P).
|
|
View larger version (127K):
[in a new window]
|
Figure 4b. Duodenal duplication. (a) CT scan shows a fluid-filled, circumferential duodenal duplication, which may be mistaken for a pancreatic mass on axial sections. (b) Coronal multiplanar reformatted image demonstrates the full extent of the duodenal duplication (*) adjacent to the pancreas (P).
|
|
View larger version (154K):
[in a new window]
|
Figure 5a. Intrapancreatic splenic rest. (a) Axial contrast-enhanced spoiled gradient-echo T1-weighted MR image shows a lesion (*) that is isointense relative to the spleen (S). P = pancreatic tail. (b) Coronal T1-weighted MR image demonstrates the pancreas wrapped around the lesion (*). P = pancreatic tail, S = spleen.
|
|
View larger version (150K):
[in a new window]
|
Figure 5b. Intrapancreatic splenic rest. (a) Axial contrast-enhanced spoiled gradient-echo T1-weighted MR image shows a lesion (*) that is isointense relative to the spleen (S). P = pancreatic tail. (b) Coronal T1-weighted MR image demonstrates the pancreas wrapped around the lesion (*). P = pancreatic tail, S = spleen.
|
|
View larger version (110K):
[in a new window]
|
Figure 6a. Choledochal cyst. (a) CT scan demonstrates a dilated, redundant common bile duct simulating a cystic lesion within the pancreatic head (*). (b) ERCP image shows contrast material filling a choledochal cyst (*).
|
|
View larger version (143K):
[in a new window]
|
Figure 6b. Choledochal cyst. (a) CT scan demonstrates a dilated, redundant common bile duct simulating a cystic lesion within the pancreatic head (*). (b) ERCP image shows contrast material filling a choledochal cyst (*).
|
|
View larger version (142K):
[in a new window]
|
Figure 7a. Complications of pancreatitis mimicking a pancreatic tumor. (a) CT scan demonstrates hemorrhagic pancreatitis as a heterogeneous mass in the area of the pancreatic bed (*). Arrow indicates active extravasation (hemorrhage). (b) Pancreatic phase helical CT scan obtained in a 70-year-old woman with a history of pancreatitis who presented with abdominal pain shows numerous thick-walled cystic lesions throughout the pancreas (*). The patient’s condition was initially diagnosed as an intraductal papillary mucinous neoplasm but later proved to be a complex pseudocyst at surgery.
|
|
View larger version (152K):
[in a new window]
|
Figure 7b. Complications of pancreatitis mimicking a pancreatic tumor. (a) CT scan demonstrates hemorrhagic pancreatitis as a heterogeneous mass in the area of the pancreatic bed (*). Arrow indicates active extravasation (hemorrhage). (b) Pancreatic phase helical CT scan obtained in a 70-year-old woman with a history of pancreatitis who presented with abdominal pain shows numerous thick-walled cystic lesions throughout the pancreas (*). The patient’s condition was initially diagnosed as an intraductal papillary mucinous neoplasm but later proved to be a complex pseudocyst at surgery.
|
|
View larger version (146K):
[in a new window]
|
Figure 8a. Autoimmune pancreatitis. (a) CT scan demonstrates an enlarged, heterogeneous pancreatic head (*) with perivascular inflammation simulating neoplastic vascular involvement (arrow). (b) Coronal half-Fourier RARE T2-weighted MR image obtained in a different patient with abdominal pain demonstrates narrowing of the intrapancreatic common bile duct (arrow) by a diffusely enlarged pancreatic head without evidence of a specific mass. (c) On an axial contrast-enhanced fat-saturated spoiled gradient-echo T1-weighted MR image obtained in a third patient, the pancreatic tail is enlarged and demonstrates a hypointense rim (arrowheads).
|
|
View larger version (148K):
[in a new window]
|
Figure 8b. Autoimmune pancreatitis. (a) CT scan demonstrates an enlarged, heterogeneous pancreatic head (*) with perivascular inflammation simulating neoplastic vascular involvement (arrow). (b) Coronal half-Fourier RARE T2-weighted MR image obtained in a different patient with abdominal pain demonstrates narrowing of the intrapancreatic common bile duct (arrow) by a diffusely enlarged pancreatic head without evidence of a specific mass. (c) On an axial contrast-enhanced fat-saturated spoiled gradient-echo T1-weighted MR image obtained in a third patient, the pancreatic tail is enlarged and demonstrates a hypointense rim (arrowheads).
|
|
View larger version (124K):
[in a new window]
|
Figure 8c. Autoimmune pancreatitis. (a) CT scan demonstrates an enlarged, heterogeneous pancreatic head (*) with perivascular inflammation simulating neoplastic vascular involvement (arrow). (b) Coronal half-Fourier RARE T2-weighted MR image obtained in a different patient with abdominal pain demonstrates narrowing of the intrapancreatic common bile duct (arrow) by a diffusely enlarged pancreatic head without evidence of a specific mass. (c) On an axial contrast-enhanced fat-saturated spoiled gradient-echo T1-weighted MR image obtained in a third patient, the pancreatic tail is enlarged and demonstrates a hypointense rim (arrowheads).
|
|
View larger version (136K):
[in a new window]
|
Figure 9. Intraabdominal lymphoma simulating a primary pancreatic mass. CT scan demonstrates an enlarged lymph node (*) adjacent to the pancreatic body and mimicking a pancreatic mass.
|
|
View larger version (140K):
[in a new window]
|
Figure 10. Superior mesenteric artery aneurysm mimicking a primary pancreatic lesion. Contrast-enhanced CT scan shows an enlarged, enhancing lumen (*) surrounded by mural thrombus in the pancreatic head. Without arterial phase imaging, these lesions may be mistaken for pancreatic masses.
|
|
View larger version (154K):
[in a new window]
|
Figure 11. Venous vascular lesion mimicking a primary pancreatic lesion. CT scan shows an occlusive portal vein thrombus (arrow). When extensive, this finding may be mistaken for a mass.
|
|
View larger version (128K):
[in a new window]
|
Figure 12. Fibrohistiocytoma mimicking a pancreatic mass. CT scan shows a retroperitoneal fibrohistiocytoma (*), which was initially diagnosed as a mucinous adenocarcinoma of the pancreas.
|
|
View larger version (140K):
[in a new window]
|
Figure 13a. Mesenteric tumorlike diseases mimicking pancreatic masses. (a) CT scan shows a carcinoid tumor manifesting as a heterogeneously attenuating mass with calcifications (*) adjacent to the head of the pancreas in the root of the mesentery. (b) CT scan obtained in a different patient shows a desmoid tumor as a large, ovoid mass compressing the pancreas dorsally (*). The tumors in both a and b simulate lesions of pancreatic origin.
|
|
View larger version (127K):
[in a new window]
|
Figure 13b. Mesenteric tumorlike diseases mimicking pancreatic masses. (a) CT scan shows a carcinoid tumor manifesting as a heterogeneously attenuating mass with calcifications (*) adjacent to the head of the pancreas in the root of the mesentery. (b) CT scan obtained in a different patient shows a desmoid tumor as a large, ovoid mass compressing the pancreas dorsally (*). The tumors in both a and b simulate lesions of pancreatic origin.
|
|
View larger version (142K):
[in a new window]
|
Figure 14a. Gastric GIST. (a) Initial CT scan shows findings that suggest a large mass (*) abutting the pancreatic tail. (b) Focused pancreatic CT scan shows a sulcus between the mass (*) and the pancreatic tail, a finding that suggests an extrapancreatic origin for the mass.
|
|
View larger version (148K):
[in a new window]
|
Figure 14b. Gastric GIST. (a) Initial CT scan shows findings that suggest a large mass (*) abutting the pancreatic tail. (b) Focused pancreatic CT scan shows a sulcus between the mass (*) and the pancreatic tail, a finding that suggests an extrapancreatic origin for the mass.
|
|
View larger version (140K):
[in a new window]
|
Figure 15a. Duodenal lymphoma. (a) CT scan demonstrates an ill-defined mass (arrowhead) involving the inferior pancreatic head and duodenum. (b) Image from an upper gastrointestinal study shows nodular mural thickening of the duodenum (arrowheads).
|
|
View larger version (117K):
[in a new window]
|
Figure 15b. Duodenal lymphoma. (a) CT scan demonstrates an ill-defined mass (arrowhead) involving the inferior pancreatic head and duodenum. (b) Image from an upper gastrointestinal study shows nodular mural thickening of the duodenum (arrowheads).
|
|
View larger version (145K):
[in a new window]
|
Figure 16. Duodenal adenocarcinoma. Contrast-enhanced CT scan shows an annular mass adjacent to the pancreatic head (arrow) and a filling defect in the distal duodenum (arrowhead). The lesion could be mistaken for a pancreatic mass owing to its location.
|
|
View larger version (118K):
[in a new window]
|
Figure 17. Spindle cell sarcoma of the duodenum. CT scan demonstrates a lobular exophytic mass (*) simulating a pancreatic lesion. The mass later proved to be a metastatic duodenal lesion.
|
|
View larger version (128K):
[in a new window]
|
Figure 18. Metastasis to the duodenum from bronchogenic carcinoma. CT scan shows a duodenal meta-static lesion (arrow) simulating a primary pancreatic lesion.
|
|
View larger version (135K):
[in a new window]
|
Figure 19. Splenic angioma. CT scan shows a large, heterogeneous mass that appears to arise from the pancreatic body and tail (arrow).
|
|
View larger version (116K):
[in a new window]
|
Figure 20a. Left extraadrenal paraganglioma. Axial fat-saturated fast spin-echo T2-weighted (a) and contrast-enhanced fat-saturated T1-weighted (b) MR images demonstrate the spatial relationship between a paraganglioma (*) and the pancreas. In this case, a clear plane of demarcation is noted between the lesion and the pancreas, which helps distinguish the mass from a primary pancreatic tumor.
|
|
View larger version (120K):
[in a new window]
|
Figure 20b. Left extraadrenal paraganglioma. Axial fat-saturated fast spin-echo T2-weighted (a) and contrast-enhanced fat-saturated T1-weighted (b) MR images demonstrate the spatial relationship between a paraganglioma (*) and the pancreas. In this case, a clear plane of demarcation is noted between the lesion and the pancreas, which helps distinguish the mass from a primary pancreatic tumor.
|
|
View larger version (130K):
[in a new window]
|
Figure 21. Metastatic breast cancer. CT scan demonstrates an infiltrative metastatic tumor (arrows) simulating a primary pancreatic mass and causing enlargement of the pancreas.
|
|
View larger version (167K):
[in a new window]
|
Figure 22. Metastatic renal cell carcinoma. Early arterial phase CT scan demonstrates a metastatic lesion in the pancreatic head (arrow), a finding that may be mistaken for a primary islet cell tumor. A renal mass arising from the left kidney with adjacent fat stranding is also seen (*).
|
|
View larger version (146K):
[in a new window]
|
Figure 23a. Metastatic sarcoma. (a) CT scan shows a metastatic osteosarcoma (*) arising from the pancreatic tail. (b) CT scan obtained in a different patient demonstrates a large, metastatic myxoliposarcoma (*) in the pancreatic head. The primary lesion had previously been resected from the buttock. (c) CT scan obtained in a third patient shows a metastatic lobular soft-tissue sarcoma in the pancreatic head effacing the duodenal lumen (arrow).
|
|
View larger version (139K):
[in a new window]
|
Figure 23b. Metastatic sarcoma. (a) CT scan shows a metastatic osteosarcoma (*) arising from the pancreatic tail. (b) CT scan obtained in a different patient demonstrates a large, metastatic myxoliposarcoma (*) in the pancreatic head. The primary lesion had previously been resected from the buttock. (c) CT scan obtained in a third patient shows a metastatic lobular soft-tissue sarcoma in the pancreatic head effacing the duodenal lumen (arrow).
|
|
View larger version (148K):
[in a new window]
|
Figure 23c. Metastatic sarcoma. (a) CT scan shows a metastatic osteosarcoma (*) arising from the pancreatic tail. (b) CT scan obtained in a different patient demonstrates a large, metastatic myxoliposarcoma (*) in the pancreatic head. The primary lesion had previously been resected from the buttock. (c) CT scan obtained in a third patient shows a metastatic lobular soft-tissue sarcoma in the pancreatic head effacing the duodenal lumen (arrow).
|
|
View larger version (147K):
[in a new window]
|
Figure 24. Focal pancreatitis caused by protease inhibitors. CT scan shows an inflammatory pseudotumor (*) in the pancreatic tail and a pseudocyst (P) compressing the gastric fundus.
|
|
Copyright © 2005 by the Radiological Society of North America.
