Spontaneous hepatic haematoma in a cat

A male 2.5-year-old American short hair cat was admitted to the animal hospital with the primary complaints of abdominal distension and depression for several days. Ultrasound revealed a large hypoechoic cavity with a well demarcated thin wall on a liver lobe. On exploratory laparotomy, a hepatic haematoma was observed. Subsequently, hepatic lobectomy was performed. Histologically, an eosinophilic substance stained with Congo red was deposited in the cyst wall which showed an optical property of apple green birefringence under polarized light. Based on immunohistochemical staining, amyloid A was diagnosed. To our knowledge, this is the first report of a spontaneous hepatic haematoma with an amyloid A deposition in a cat.