Favorable short- and long-term outcomes reported for cats following surgical management of biliary cystadenomas

Objective: To describe the clinical presentation, perioperative variables, surgical management, and outcomes in cats that underwent surgery for biliary cystadenomas. Animals: 21 cats met inclusion criteria. These cats had surgery for biliary cystadenomas between 2008 and 2023, with a corresponding histopathologic diagnosis. Clinical Presentation: Cats were reported as domestic shorthair (15 of 21), domestic longhair (3 of 21), Himalayan (1 of 21), Ragdoll (1 of 21), and Persian (1 of 21). This included 13 neutered males and 8 spayed females with a median age of 13 years. Cats most commonly presented with nonspecific clinical signs such as vomiting, weight loss, hyporexia, and lethargy. Cats were occasionally subclinical with a liver mass identified on physical examination or abdominal imaging. Results: Surgery was pursued based on a variety of factors, including comorbidities requiring surgery, features of the mass, and clinical signs attributed to the mass. Major surgical complications were uncommon, and the perioperative mortality rate was 10% (2 of 21). Three cats had concerns for malignant transformation on histopathology. The recurrence rate was 22% (4 of 18) for the cats with follow-up. The biliary cystadenoma was not the life-limiting issue for cats that survived the perioperative period. The median survival time was 570 days with 1-, 2-, and 3-year survival rates of 67%, 43%, and 15%, respectively. Clinical Relevance: Cats had positive short-term outcomes and long-term prognosis, and surgery should be considered for suspected biliary cystadenomas to obtain a definitive diagnosis and address associated morbidity. The potential for malignant transformation exists for feline biliary cystadenomas.