Intestinal neoplasia: A review of 34 cases

Abstract

Summary 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.

Intramural jejunal leiomyoma as a cause of colic

“…They have been reported most commonly in the reproductive tract, with other rare reports in the oesophagus and omentum. There have been few known case reports of leiomyomas in horses occurring in the jejunum, as well as in the duodenum and small colon (Collier and Trent 1983; Haven et al 1991; Mair et al 1992; Kasper and Doran 1993; Schaudien et al 2007; Spanton et al 2018). One previous report of a leiomyoma in the jejunum did not characterise the mass, only describing the final diagnosis (Collier and Trent 1983).…”

Colonic T-cell–rich, large B-cell lymphoma associated with equid herpesvirus 5 infection and secondary trans-colonic fistula in a horse

“…18,20 Other less commonly reported alimentary neoplasms include leiomyoma, squamous cell carcinoma, myxosarcoma, ganglioneuroma, peripheral nerve sheath tumor, and carcinoid. 16,18 Alimentary lymphoma is the third most commonly reported equine lymphoma, behind multicentric and cutaneous lymphoma. 2,5,18 There is no reported breed or sex predisposition for alimentary lymphoma, which is typically seen in adult horses.…”

“…2,5,18 There is no reported breed or sex predisposition for alimentary lymphoma, which is typically seen in adult horses. 5,16,18 This neoplasm has been reported in both the small and large intestines, with higher prevalence in the small intestine. When concurrent infiltration of both the small and large intestinal segments occurs, alimentary lymphoma may be difficult to differentiate from multicentric lymphoma.…”

“…When concurrent infiltration of both the small and large intestinal segments occurs, alimentary lymphoma may be difficult to differentiate from multicentric lymphoma. 2,5,[16][17][18] Primary alimentary lymphoma has been suggested to develop from the gut-associated lymphoid tissue (GALT). 18 The presence of tumor cells in multiple locations in our case makes determination of the origin of the lymphoma more challenging; however, potential primary sites may include the GALT, one or more mesenteric lymph nodes, or a multicentric lymphoma originating in the abdominal lymph nodes, although this seems less likely given that no extra-alimentary organ systems or distant lymph nodes were affected.…”

“…12 Lymphopenia has been reported in horses with lymphoma, and hypoalbuminemia is commonly seen and attributed to both protein-losing enteropathy associated with mucosal damage and decreased production as a negative acute-phase protein. 9,12,16,18 Intestinal fistulas are rare, abnormal communications between gastrointestinal lumina in different segments. 24 Common acquired causes of intestinal fistulas include postsurgical complications, trauma, presence of a foreign body, inflammatory bowel disease, diverticulitis, neoplasia, and chemotherapy or radiation treatment.…”