Intestinal neoplasia: A review of 34 cases

The clinicopathological features of 34 horses with a histological diagnosis of intestinal neoplasia were reviewed; these included 17 horses with lymphoma, five with gastrointestinal stromal tumours (GISTs), four with adenocarcinomas, three with leiomyosarcomas, two with leiomyomas, two with squamous cell carcinomas (SCC) and one with adenocarcinoma/mesothelioma. The mean age at presentation was 19 years (range 3-36 years), and 81% of cases occurred in horses aged 15 years or older. Weight loss, acute or recurrent colic, inappetence, diarrhoea, depression and pyrexia were the most common presenting clinical signs. Hyperfibrinogenaemia, hypoalbuminaemia and leukocytosis were the most common clinical pathological findings. Transabdominal ultrasonography and exploratory laparotomy were the most useful diagnostic tests. Neoplasia was identified in all regions of the intestinal tract, with the jejunum being most frequently affected. The presence of mass lesions or thickened intestinal walls on transabdominal ultrasound, coupled with other clinical findings, were suggestive of intestinal neoplasia. Where possible, complete surgical resection offered the best prognosis, but generally the prognosis was poor to hopeless.