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• A 5kg 11-year 10mo old female spayed Poodle mix presented the Schwarzman Animal Medical Center’s Emergency Service as a referral hemoabdomen. No prior history of pathology or trauma.
• Referral diagnostics: mildly progressive anemia (PCV 42% > 33%), moderate mixed hepatopathy, mild hyperbilirubinemia
• Patient presented in hypovolemic shock with abdominal distension and poor peripheral pulses
• Point-of-care abdominal ultrasound showed moderate volume peritoneal effusion
• Diagnostic abdominocentesis confirmed hemoabdomen
• Thoracic radiographs were unremarkable except for loss of cranial abdominal serosal detail
Findings:
• Large, irregularly marginated, somewhat rounded, non-contrast enhancing, soft tissue attenuating mass in the cranial left abdomen. The quadrate lobar artery originates normally from the hepatic artery and extends into the mass where it becomes severely, abruptly attenuated. The right lateral aspect of the mass broadly abuts the pylorus. A normal quadrate hepatic lobe is not distinctly identified to the left of the gallbladder.
• Mildly rounded margins of the remainder of the liver
• Mineral attenuating material settled along dependent portion of gallbladder
• Hepatic lymph node is mildly enlarged, rounded, and mildly heterogeneously contrast enhancing
• Moderate volume of peritoneal effusion
• Mild pleural effusion noted with rounding of the pleural margins
Conclusions
• Large non-contrast enhancing left cranial abdominal mass expanding from the severely attenuated quadrate lobar hepatic artery. Primary consideration is given to quadrate liver lobe torsion. An underlying hepatic neoplasm cannot be entirely ruled out (e.g. hepatocellular carcinoma, round cell neoplasia, hemangiosarcoma). A hepatic mass alone with vascular congestion or thrombosis is considered less likely. Adhesion to the pylorus is also considered.
• Mild diffuse hepatopathy. Consider congestion, vacuolar hepatopathy, hepatitis, or possibly infiltrative neoplasia
• Mild hepatic lymphadenopathy. Primary consideration is given to reactivity. Metastasis cannot be entirely ruled out.
• Moderate peritoneal effusion, consistent with reported hemoperitoneum.
• Moderate pleural effusion. Consider secondary to inflammation/vasculitis. A hemorrhagic or neoplastic effusion is considered less likely.
Exploratory laparotomy revealed a quadrate liver lobe torsion with severe enlargement, congestion and caudal displacement of the affected lobe with associated clot formation. A quadrate liver lobectomy and right lateral liver lobe punch biopsy were performed. The torsed hepatic lobe did not appear to be adhered to the stomach.
Histopathology Excisional biopsy quadrate liver lobe: extreme hepatic congestion with hepatocyte necrosis consistent with hepatic torsion. Right lateral liver lobe punch biopsy: periportal and random, severe, plasmacytic, neutrophilic and lymphocytic hepatitis
Two days post-operatively patient became acutely, severely dyspneic. Thoracic radiographs confirmed a severe, diffuse, alveolar lung pattern and acute respiratory distress syndrome (ARDS) was prioritized. Humane euthanasia was elected due to clinical deterioration. Necropsy confirmed pulmonary parenchymal changes consistent with ARDS most likely secondary to ischemia and reperfusion injury. Evidence of pancreatitis also noted as a potential inciting cause.
Liver lobe torsions (LLT) are rarely identified surgical emergencies in dogs. Quadrate liver lobe torsions are exceedingly rare. A canine quadrate liver lobe torsion has been reported twice, once in a 12-year-old male neutered beagle (2) and once in conjunction with a right lateral lobe torsion and GDV in an 11-year-old female spayed German Shepherd Dog (6). The most common scenario is a left divisional (left lateral or left medial) liver lobe torsion in a larger breed dog often with a history of acute onset lethargy and collapse (3). Damage to any of the supportive ligaments (falciform, left and right triangular, and left and right coronary ligaments) and prior history of GDV or chronic gastric distention are all proposed risk factors for liver lobe torsions (3,7). Computed tomography (CT) is the most sensitive diagnostic imaging modality for diagnosis of canine LLT. CT of canine LLT is characterized by an enlarged, hypoattenuating, minimally to non-contrast enhancing mass in the liver and varying degrees of mono or bicavitary effusion (1,3,7). The hepatic mass may be heterogeneous containing fluid and/or gas. Hepatic lymph node enlargement is also supportive of a liver lobe torsion. Although not identified in this case, contrast-phase CT also has the potential of showing vascular patterns (whirl sign and vascular interruption) that, when present, are consistent with a torsion (3). Contrast-phase CT is the most sensitive modality for differentiating a liver mass from a liver lobe torsion and it is the most reliable tool for surgical planning. Patient survival is contingent upon timely recognition and emergency liver lobectomy (3).
References:
1. Schwartz S.G.H., Mitchell, S.L., Keating, J.H., & Chan, D.L. (2006) \”Liver lobe torsion in dogs: 13 cases (1995 – 2004).\” Journal of the American Veterinary Medical Association, AVMA, 228 (2): 242-247.
2. Sonnenfield, J.M. et al. (2005). \”Radiographic and ultrasonographic findings of liver lobe torsion in a dog\”. Veterinary Radiology & Ultrasound, 42: 344-346.
3. Cordella, A. and Bertolini G. (2021). “Multiphase multidetector-row computed tomographic and ultrasonographic findings in dogs with spontaneous liver lobe torsion.” Research in Veterinary Science 135:192-199.
4. Leela-Arporn, R. et al. (2019). ”Computed tomographic features for differentiating benign from malignant liver lesions in dogs.” Journal of Veterinary Medical Science 81 (12): 1697-1704.
5. Sumping, J.C., O’Connell, E.M., Mortier, J. (2020). “Computed tomographic and clinical findings in a dog with suspected liver lobe torsion, secondary disseminated intravascular coagulation and multiorgan infarction.” Veterinary Record Case Reports, 8(4): e001166.
6. Massari, F. et al. (2012). “Torsion of quadrate and right middle liver lobes and gallbladder in a German Shepherd Dog.” Australian Veterinary Journal, 90 (1-2): 44- 47. 7. Kahn, Z., Gates, K., and Simpson, S.A. (2016). “Bicavitary effusion secondary to liver lobe torsion in a dog.” Veterinary Medicine: Research and Reports, 7:53-58.