Veterinary Ultrasound Society

8-year-old neutered Maine Coon cat

Lethargy and inappetence; jaundice and pyrexia

  • 8-year-old neutered Maine Coon cat presented for signs of lethargy and inappetence.
  • Clinical examination revealed generalised jaundice, pyrexia (Temp 40.2 C), moderate pain at the abdominal palpation.
  • Blood results: hyperbilirubinemia, moderate elevation of the liver enzymes, neutrophilia, leucocytosis, hypercholesterolaemia.

 

  • An ovoid to round structure with hyperechoic central aspect is localised at the level of the duodenal papilla, with moderate mass effect, measuring approximately 7.2/5.9 mm. Ante and retrograde movement of the pyloric fluid is also noted at the level of the duodenal papilla. Rest of the ultrasound exam was within normal limits. Color Doppler interrogation at the level of the duodenal papilla. Iso to hyperechoic round structure is noted at the level of the duodenal papilla causing secondary obstruction of the pancreatic and biliary duct.
  • Homogeneous liver parenchyma with mild echo-rich periportal cuffing.  Moderate distension of the intrahepatic biliary ducts.
  • Moderate distension of the gallbladder and hyperechoic pericholecystic area. Hyperechoic sediment within gallbladder lumen. Mildly thickened gallbladder walls.
  • Hypo/iso-echoic pancreas with nodular aspect and moderate dilation of the pancreatic duct (measuring 4.6 mm). Peri-mesenteric area is seen as hyperechoic. Moderately enlarged pancreas, hypo and iso echoic to the surrounding tissue.
  • Free peritoneal fluid, mostly localised at the level of the pancreas, initial portion of the duodenum, liver and gallbladder.
  • Mild duodenal corrugation.
  • Moderate diffuse generalized pancreatic thickening with generalized dilation of the common pancreatic duct and mild regional peritoneal effusion and/or steatitis.
  • Marked generalized dilation of the common of the common bile duct and mild dilation of the right intrahepatic biliary duct likely secondary to extra-hepatic biliary tract obstruction.
  • Mildly thickening of the major duodenal papilla. These changes could represent inflammation and/or infiltrative neoplasia (e.g. lymphoma).
  • Cholangitis/cholangiohepatitis/ extra-hepatic biliary tract obstruction/ pancreatic duct obstruction/ pancreatitis nodule-nodular hyperplasia vs neoplasia. The enlarged pancreas, dilation of the pancreatic duct and regional steatitis with peritoneal effusion are likely secondary to pancreatitis. Dilation of the pancreatic duct secondary to aging is also possible and cannot be excluded. The focal thickening at the tip of the left limb of the pancreas could represent nodular hyperplasia and/or neoplasia.
  • The extra hepatic biliary obstruction could be secondary to the pancreatitis and/or changes in the duodenal papilla. There was no evidence of disruption/rupture of the gallbladder wall.

 

A CT scan has been performed, to assess the integrity of the gallbladder and attenuation of the nodular aspect of the duodenal papilla. CT results: Moderate to markedly distended gallbladder with the caudal margin extending beyond the hepatic margins. The gallbladder wall is mildly diffusely thickened measuring 1.6 mm. No changes have been seen at the level of the local peritoneal space. The peritoneal space surrounding the gallbladder is normal. The cystic duct and common bile duct (orange arrows) are mildly and markedly distended by fluid measuring 4 mm and up to 6.9 mm in diameter, respectively. The wall of the cystic and common bile duct is mildly diffusely thickened. At the level of the junction between the common bile duct with the duodenal papilla, there is ill defined hyperattenuating structure (green circle). The duodenal papilla is mildly thickened and has faint central contrast enhancement. There is mild regional peritoneal effusion in this region (light blue arrows). The liver is normal in shape and margination. In the caudodorsal aspect of the right division of the liver there is an intrahepatic biliary duct (green arrow) mildly distended by fluid measuring 2.5 mm in diameter and its wall is mildly diffusely thickened. The pancreas (red arrows) is mildly to moderately enlarged measuring 5.6 mm on the right limb, 10 mm in the body and 8.5 mm on the left limb. At the tip of the limb of the pancreas there is a focal ill-defined isoattenuating and contrast enhancing thickening that deforms the pancreatic capsule (pink arrows) and measures approximately 9.2 x 7.3 mm. There is mild to moderate fluid and fat stranding surrounding the pancreas (light blue arrows), notably the left limb. The pancreatic duct (dark blue arrows) is moderately diffusely distended by fluid measuring up to 3 mm in the pancreatic body.

 

Ultrasound is used in the diagnosis of feline hepatobiliary disease. Ultrasound abnormalities in cats with cholangiohepatitis and cholecystitis include gallbladder wall thickening, choleliths, bile ducts thickening and dilation, enlarged pancreas, and gallbladder sludge. Gallbladder wall thickening can be found with cholecystitis, cholangitis, oedema, cystic mucinous hyperplasia, pericholecystic free fluid, and systemic disease unrelated to the gallbladder. Inflammatory processes involving the biliary and pancreatic tract can be associated with amorphous plugs, cholelithiasis, neoplasia, fibrotic tissue, foreign body. although it is often difficult to determine what came first (Mayhew et al. 2002). The common biliary duct, pancreatic duct and duodenal papilla must be evaluated thoroughly for the presence of echogenic amorphous plugs and choleliths, which may or may not cause acoustic shadowing.

Even ultrasound examination is used usually in diagnosis of liver and biliary tract pathologies, CT scan is better in evaluation the hepatobiliary disorders, possible nodules, attenuation and gives a perfect 3D view of the local anatomy.

In this case, the patient has been managed symptomatically, blood results improving gradually in a 5-day course, full recovery being achieved. In the presented case the main differential diagnosis was between duodenal papilla obstruction from inflammation/infection versus neoplasia.  Response to therapy supported inflammation/infection.

 

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