Perirenal expanding haematoma in a cat

A four-year-old, entire male domestic cat was referred for assessment of a large abdominal mass of three-weeks duration. Diagnostic imaging suggested the presence of either splenic neoplasia, an abdominal abscess or haematoma. A coeliotomy was performed and an enlarged, irregular mass, including the left kidney and adrenal gland, was identified. The mass was removed, requiring a left adrenalo-uretero-nephrectomy. The aorta was accidentally punctured during the procedure, resulting in paraplegia. Given a poor prognosis, the owners decided to have the cat euthanased. Histological examination of the mass was characteristic of a chronic expanding haematoma.