VUS Case of the Month - December 2018/January 2019

Submitted by: Eunbee Kim, DVM and Stephanie Seller, DVM
, Animal Medical Center, NY, NY.

Signalment & History:

  • 10-year-old neutered male Toy Poodle was for a 1 week history of lethargy and inappetence.
  • At the pDVM, the patient was tachycardic, unwilling to move and was tense and painful on abdominal palpation. In-house bloodwork revealed elevated liver enzymes, neutrophilia with suspected bands, and hypoglycemia. Abdominal radiographs were consistent with abdominal effusion. Abdominocentesis confirmed serosanguinous fluid containing a moderate amount of neutrophils with no intracellular bacteria.
  • Upon referral, bloodwork revealed severe hemoconcentration with relative hypoproteinemia (74%/6 g/dL), hyperlactatemia (7.24 mmol/L). Comprehensive bloodwork revealed elevated ALP (300), TBili (0.4), GGT (41). Repeat abdominocentesis was performed and submitted for cytology. Thoracic radiographs were unremarkable.
  • The patient was admitted and an abdominal ultrasound was performed.

 

ANSWER:

  • A moderate volume of highly echogenic peritoneal effusion is noted, concentrated around the liver and cranial to the urinary bladder. Cranial to and left of the urinary bladder, there is an approximately circular, organized structure comprised of hyperechoic striations in a stellate pattern. This structure is not vascularized on Doppler interrogation. The peritoneal effusion is noted to move around the structure, but the structure itself does not move with the fluid. The gallbladder is identified in a normal location in the right liver, and contains a small amount of echogenic material. The wall is somewhat undulating in margin, with a questionable discontinuity identified in the ventral aspect. The common bile duct is not identified, and is somewhat obscured by the peritonitis.
  • Stellate structure in the left caudal abdomen most likely represents extrusion of a gallbladder mucocele. The moderate echogenic effusion and widespread peritonitis is most consistent with bile peritonitis secondary to the migrating mucocele.
  • The patient was taken into surgery for an emergency abdominal explore and the ruptured gallbladder and migrating mucocele were confirmed intraoperatively. Additionally, a sample of the gallbladder was submitted for histopathology.

COMMENTS:

Fluid Cytology Report:

  • Protein 3.1 g/dL, RBC <100,000, Nucleated Cell Count 12,902 cells/uL. Cells consist primarily of nondegenerative neutrophils (77%) with scattered activated macrophages (22%) and fewer small mature lymphocytes (1%). Clumps of amorphous/mucinous basophilic material (consistent with white bile) are present. The cells are surrounded by a moderate amount of blood and basophilic proteinaceous tissue fluid background. No organisms observed.
  • Addendum: The bilirubin concentration of the fluid is 6.8 mg/dL which coupled with the presence of "white bile" and serum bilirubin levels confirm atypical bile peritonitis.

Histopathology of Gallbladder:

  • The gallbladder wall is expanded by granulation tissue proliferation with hemorrhage and accompanying neutrophilic and lymphoplasmacytic infiltrates.
  • Ruptured mucocele with granulation tissue proliferation, hemorrhage, and neutrophilic and lymphoplasmacytic inflammation.