Case Presentation
A middle-aged, castrated domestic shorthair cat presented for a wellness examination. The owner stated that the pet seemed normal and healthy. During the physical examination, a large, noncompressible mass was palpable on the left side of the cranial abdomen. The results of a presurgical workup, including a minimum database, a coagulopathy panel, and thoracic radiography, were within normal limits. Ultrasonography of the abdominal cavity revealed a large hyperechoic and hypoechoic mass involving the left liver lobe. Surgical exploration of the abdomen revealed the abnormal mass in the picture above. The entire lobe was resected using a transverse stapling instrument, and the patient fully recovered.
1. What is this common mass lesion of the liver in older cats?
2. Is it benign or malignant?
3. What is the recurrence rate?
Answers and Explanations
1. Biliary adenoma. Other nomenclature for these tumors includes biliary cystadenoma, bile duct adenoma, and cholangiocellular adenoma.1
2. Benign. However, early surgical excision is highly recommended because malignant transformation may occur. Biliary adenomas may be single or multiple. Ultrasonography is helpful in determining whether surgery is an option (only in the case of a single lesion).1
3. Resection of the mass should be locally curative, but similar, independent lesions may develop in other liver lobes. Unrelated tumors (e.g., lymphoma, mast cell tumor) have been reported in some cats with biliary adenomas. Therefore, it is important to fully evaluate all organ systems and conduct complete staging.1
Downloadable PDF
1. Ogilvie GF, Moore AS: Feline Oncology. Yardley, PA, Veterinary Learning Systems, 2001, pp 305–306.
