Korean J Radiol.  2003 Sep;4(3):157-162. 10.3348/kjr.2003.4.3.157.

Differential Diagnosis of Benign and Malignant Intraductal Papillary Mucinous Tumors of the Pancreas: MR Cholangiopancreatography and MR Angiography

• Choi BS
• Kim TK
• Kim AY
• Kim KW
• Park SW
• Kim PN
• Ha HK
• Lee MG
• Kim SC

• KMID: 754019
• DOI: http://doi.org/10.3348/kjr.2003.4.3.157

Abstract

OBJECTIVE
To compare the usefulness of magnetic resonance cholangiopancreatography (MRCP) and MR angiography (MRA) in differentiating malignant from benign intraductal papillary mucinous tumors of the pancreas (IPMTs), and to determine the findings which suggest malignancy. MATERIALS AND METHODS: During a 6-year period, 46 patients with IPMT underwent MRCP. Morphologically, tumor type was classified as main duct, branch duct, or combined. The diameter of the main pancreatic duct (MPD), the extent of the dilated MPD, and the location and size of the cystic lesion, septum, and communicating channel were assessed. For all types of IPMTs, enhanced mural nodules and portal vein narrowing were evaluated at MRA. RESULTS: Combined-type IPMTs were more frequently malignant (78%) than benign (42%) (p < 0.05). Compared with benign lesions, malignant lesions were larger, and the caliber of the communicating channel was also larger (p < 0.05). Their dilated MPD was more extensive and of greater diameter (p < 0.05), and the presence of mural nodules was more frequent (p < 0.001). CONCLUSION: Combined MRCP and MRA might be useful for the differential diagnosis of malignant and benign IPMTs of the pancreas.

Keyword

Pancreas, neoplasms; Pancreas, MR; Pancreatic ducts, MR

Figure

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  Fig. 1 A 60-year-old man with benign main duct-type IPMT of the pancreas. Single-slab MRCP image (TR/TE, infinite/1200) shows diffuse dilatation of the main pancreatic duct (arrows).

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  Fig. 2 A 44-year-old man with benign branch duct-type IPMT of the pancreas. Single-slab MRCP image (TR/TE, infinite/1200) depicts a multilocular cystic lesion (arrowheads) in the pancreatic uncinate process and a narrow channel (arrow) which communicates with the pancreatic duct.

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  Fig. 3 A 67-year-old man with benign combined duct-type IPMT of the pancreas. Single-slab MRCP image (TR/TE, infinite/1200) reveals a multilocular cystic lesion (arrowheads) in the pancreatic body and diffuse mild dilation of the main pancreatic duct (arrow).

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  Fig. 4 A 64-year-old woman with malignant branch duct-type IPMT of the pancreas. Single-slab MRCP image (TR/TE, infinite/1200) demonstrates a grapelike cluster of cysts (arrowheads). The main pancreatic duct is not dilated. Another small cystic lesion (arrow), not resected at surgery, is seen in the pancreatic tail.

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  Fig. 5 A 71-year-old man with malignant combined duct-type IPMT of the pancreas. Single-slab MRCP image (TR/TE, infinite/1200) depicts a grapelike cluster of cysts (arrowheads) in the pancreatic head. Marked diffuse dilation of the main pancreatic duct is observed (arrows).

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  Fig. 6 A 44-year-old man with malignant combined duct-type IPMT of the pancreas. The MRA source image (TR/TE, 4.6/1.8) shows an enhancing mural nodule (arrow) and a thick irregular septum in the multilocular cystic lesion (arrowheads) of the pancreatic head.

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  Fig. 7 Scatterplot showing the size of mural nodules in benign and malignant IPMTs of the pancreas. Some overlap is apparent, but in benign IPMTs the mural nodule is less than 10 mm in diameter.

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