Clinical and Surgical Management of Dog with Diffuse Cholangiocarcinoma

Background: Cholangiocarcinoma is an epithelial cell malignancy arising at various locations within the biliary tree. Primary liver tumors can be classified morphologically as solid, when a single large tumor involves only one liver lobe; nodular, when multiple tumors are located in different liver lobes; diffuse, when either multifocal nodular changes occur in different liver lobes or when diffuse changes occur throughout the liver. Surgery is the treatment of choice for these tumors because there is no established, effective chemotherapy protocol. This paper reports on the management of a dog with diffuse cholangiocarcinoma.Case: A 13-year-old female, castrated Pinscher, weighting 6 kg, was admitted at the Veterinary Medical Teaching Hospital of the Federal University of Rio Grande do Sul (UFRGS) with clinical signs of abdominal distension and dyspnea that had started one month ago. The patient had been subjected to total unilateral mastectomy to remove an adenocarcinoma. At clinical examination, the animal presented anemia, an area of silence during pulmonary auscultation on the right hemithorax,and hepatomegaly. Because of the chronicity and nonspecific signs, additional tests were requested. Abdominal ultrasound exam showed hepatomegaly with irregular echotexture; cavity areas scattered throughout the organ, especially by the right medial lob; discrete presence of free abdominal fluid. Thoracic radiography showed increased radiopacity in themedial and caudal right hemithorax, suggesting metastasis. Laboratory tests included a complete blood count (normocytic mycrocytic anemia), an albumin count (27.49 g/L), an alanine amino-transferase test (77.40 U/L), an alkaline phosphatase test (284.94 U/L), a creatinine test (0.81 mg/dL), a conjugated bilirubin test (0.1 mg/dL), a not conjugated bilirubin test (0.1mg/dL), and a total bilirubin test (0.2 mg/dL). After blood transfusion, a hepatic lobectomy was performed. An incision was made along the ventral midline. A tumoral mass, approximately 20 cm in diameter, was observed in the right medial lobe, as well as diffuse changes throughout all hepatic lobes. A total lobectomy was performed by applying the mass ligationtechnique by placement of a circumferential ligature around the liver hilus. The abdominal cavity was sutured routinely. Histopathological examination showed primary cholangiocarcinoma. The animal had excellent postoperative recovery after six days. Subsequently, the patient again succumbed to hepatomegaly, ascites, anemia, and lethargy, and the ownerchose to euthanize the patient and did not authorize a necropsy.Discussion: The cholangiocarcinoma was classified as primary and diffuse because of the macroscopic characteristics of the liver, since there were diffuse changes throughout the organ. Surgical excision was the treatment of choice. Although the prognosis was better in the early stages, lobectomy was chosen in order to improve the patient’s respiratory condition and, consequently, improve the quality of life. There were no surgical complications and the patient presented good postoperative recovery. After 60 days of the surgical procedure, clinical signs recurred (anemia, hyporexia and abdominal distension) and euthanasia was performed. Hepatic lobectomy in an animal with advanced stage cholangiocarcinomaprovided good quality of life for a period of 60 days.Keywords: neoplasm, liver, surgery, hepatectomy