Multiple biliary duct hamartomas in a cat resulting in a hepatic mass: A case report.

A 13-year-old, male neutered domestic short-haired cat was diagnosed with multiple biliary duct hamartomas after liver lobectomy for a suspected malignant hepatic mass. Distinguishing ultrasonographic findings included a lobular, mostly well-defined, heterogeneous, predominantly hyperechoic, left hepatic mass. Computed tomography (CT) confirmed the presence of a lobular, well-defined, fluid to soft tissue attenuating, heterogeneously hypoenhancing left divisional hepatic mass. Grossly, a large left sided multilobular pale pink gelatinous hepatic mass was surgically excised. Histopathologically, the mass was composed of irregular cystic spaces lined by cuboidal epithelium and separated by mature regular fibrous tissue. Three months following surgery there was no evidence of recurrence or progression of disease on repeat abdominal ultrasound (AUS).