83 Solid Pancreatic Masses on Computed Tomography

CLINICAL IMAGAGINGAN ATLAS OF DIFFERENTIAL DAIGNOSIS

EISENBERG

DR. Muhammad Bin Zulfiqar PGR-FCPS III SIMS/SHL

• Fig GI 83-1 Pancreatic carcinoma. (A) Noncontrast scan demonstrates a homogeneous mass (M) in the body of the pancreas. (B) Contrast-enhanced scan at the time of maximum aortic contrast shows enhancement of the surrounding vascular structures and normal pancreatic parenchyma, while the pancreatic carcinoma remains unchanged and thus appears as a low-density mass.162

• Fig GI 83-2 Pancreatic carcinoma (rapid growth and arterial encasement). (A) Initial scan demonstrates a focal change in the shape of the ventral contour of the pancreas at the junction of the body and head (arrow). There is no enlargement of the pancreatic tissue. This was initially interpreted as representing an anatomic variant. (B) Three months later, a repeat scan shows a focal tumor mass (closed arrow) in the location of the focal contour abnormality seen in (A). A dynamic CT scan after the intravenous bolus injection of contrast material demonstrates the splenic and hepatic arteries at the base of the tumor. Note that the hepatic artery (open arrow) has an irregular contour. Arteriography showed encasement by this unresectable tumor.162

• Fig GI 83-3 Insulinoma. Contrast scan demonstrates a homogeneously enhancing mass (arrow) in the neck of the pancreas in an elderly man who presented with life-threatening hyperglycemia.170

• Fig GI 83-4 Vipoma. Contrast scan in an elderly man with watery diarrhea shows a huge mass with internal septa and calcification in the body and tail of the pancreas.170

• Fig GI 83-5 Islet cell tumor (nonfunctioning). Coronal CT image shows a large mass (arrow) in the left upper quadrant replacing the pancreas and invading the portal vein.170

• Fig GI 83-6 Solid and papillary epithelial neoplasm. (A) Contrast CT scan shows a mixed solid and cystic mass in the pancreatic head (arrows). (B) Axial T1-weighted MR image shows areas of high signal intensity due to hemorrhage within the mass (arrow).171

• Fig GI 83-7 Metastatic renal cell carcinoma. Multiple enhancing nodular masses (arrows) in the pancreatic body and tail.172

• Fig GI 83-8 Peripancreatic lymph node metastases. Massive nodal enlargement (arrows) with obliteration of fat planes between the mass and the head of the pancreas.

Fig GI 83-9 Lymphoma. Huge mass infiltrating the head of the pancreas (straight arrows). The curved arrow points to stones in the gallbladder.

• Fig GI 83-10 Acute pancreatitis. Diffuse enlargement of the pancreas (P) with obliteration of peripancreatic fat planes by the inflammatory process. Note the extension of the inflammatory reaction into the transverse mesocolon (arrows).173

• Fig GI 83-11 Acute gallstone pancreatitis. (A) There is enlargement of the head of the pancreas (P) with inflammatory reaction surrounding peripancreatic fat planes (arrow). (B) A stone (white arrow) is seen in the gallbladder and the common bile duct is enlarged (black arrow).

• Fig GI 83-12 Chronic pancreatitis. There is pancreatic atrophy along with multiple intraductal calculi and dilatation of the pancreatic duct (arrow). The calcifications were not seen on plain abdominal radiographs.122

• Fig GI 83-13 Pancreatic abscess. There is a gascontaining abscess (small arrows) in the pancreatic bed, with marked anterior extension (large arrow) of the inflammatory process.

• Fig GI 83-14 Pancreatic abscess after a gunshot wound. There are multiple intrapancreatic and peripancreatic gas bubbles (closed arrows), bullet fragments (open arrows), a small renal laceration, and an extrarenal hematoma (H).89

• Fig GI 83-15 Cystic fibrosis. Contrast scans at the level of the pancreatic tail (A) and head (B) show complete replacement of the pancreatic parenchyma by fat (arrows). There is also enlargement of the spleen.174

• Fig GI 83-16 Pancreatic cystosis. (A) Contrast CT scan shows multiple cysts (*) in the region of the pancreas (P), which is completely replaced by fibrofatty tissue. The cyst walls have a somewhat higher attenuation than the musculature. The lesion is located along the splenic vein (Sv), and its most lateral part is situated between the left kidney (K) and the spleen (S).175 (B) T2-weighted MR image in another patient shows innumerable cysts (arrows) replacing the pancreatic parenchyma.174

• Fig GI 83-17 Normal enhanced duodenum. (A) Initial CT scan shows findings that suggest enlargement of the head of the pancreas (*). (B) Repeat scan obtained with additional contrast material shows a normal pancreatic head, with contrast material in the duodenum (arrow) and gallbladder (*).174

• Fig GI 83-18 Annular pancreas. Pancreatic tissue surrounds the duodenum (*).174

Fig GI 83-19 Venous vascular lesion. Occlusive portal vein thrombus (arrow). When this extensive, this finding may be mistaken for a mass.174

• Fig GI 83-20 Mesenteric tumor-like disease. (A) Carcinoid tumor appears as a heterogeneously attenuating mass with calcifications (*) adjacent to the head of the pancreas in the root of the mesentery. (B) Desmoid tumor presents as a large, ovoid mass compressing the pancreas dorsally (*). Both of these tumors simulate lesions of pancreatic origin.174

• Fig GI 83-21 Gastric GIST. (A) Initial scan shows an apparent large mass (*) abutting the tail of the pancreas. (B) Focused pancreatic scan shows a sulcus between the mass (*) and the pancreatic tail (arrow), suggesting an extrapancreatic origin for the mass.174