Intestinal Neoplasia in Dogs and Cats

Intestinal Neoplasia in Dogs and Cats

• Intestinal neoplasia is not common in dogs and cats, with gastric tumors being less common than intestinal ones.
• Gastric tumors are approximately 1% of gastrointestinal tract tumors.
• Intestinal tumors are approximately 3% of gastrointestinal tract tumors.
• Intestinal tumors are about half malignant.
• Male dogs are more frequently affected than females (2.5:1 ratio).
• Older dogs are more prone to developing stomach cancer, usually adenocarcinoma.
• Seventy to eighty percent (70-80%) of stomach cancers metastasize to local lymph nodes (LNs).
• Many leiomyosarcomas and leiomyomas have been reclassified as gastrointestinal stromal tumors (GISTs).

Gastric Tumors

• GISTs express CD117 (c-kit), while leiomyomas and leiomyosarcomas do not.
• Gastric adenocarcinoma in dogs has a poor prognosis, with survival times ranging from one to two months with treatment.
• Primary gastric tumors are rare in cats, with lymphoma being a more common occurrence.
• Benign stomach lesions include adenomas and hypertrophic gastropathy (aka Chronic Hypertrophic Pyloric Gastropathy). This is more frequently seen in Shih-Tzus and Lhasa Apsos.

Intestinal Tumors

• Intestinal tumors are more common than gastric and esophageal tumors.
• In cats, lymphoma is the most common small intestinal (SI) tumor, representing 75% of cases.
• Dogs with SI tumors have an approximate distribution of 30% lymphoma, 30% carcinoma and 25% GIST/smooth muscle.
• Older male dogs tend to develop smooth muscle tumors and lymphoma.
• Overall, large intestinal (LI) tumors are more common than SI tumors in dogs.

Intestinal Tumors: Types

• Alimentary adenocarcinomas (ACAs) in cats typically occur in the small intestine (SI), whereas in dogs, they are more common in the colon or rectum.
• GISTs/leiomyosarcomas/leiomyomas are also found in the SI, and are often found in the cecum, which demonstrates a higher tendency for tumors than ACAs.
• Adenomatous polyps are found in the rectum of dogs and duodenum of cats.
• Carcinoids, which originate from endocrine cells, are not true epithelial tumors. They can secrete hormones like serotonin (5-HT), secretin, somatostatin, and gastrin (gastrinomas).

Diagnosis

• History: Vomiting (e.g., coffee grounds), melena (black, tarry stool), hematochezia (bloody stool), anorexia, weight loss
• Physical exam: Palpable mass, abdominal pain/discomfort, weight loss
• Diagnostic tests: Complete blood count (CBC), biochemical panel, possible radiological examination, ultrasound, fine needle aspirate (FNA), excisional biopsy (laparotomy), and lymph node biopsy.

Diagnosis of Intestinal Obstruction

• Oral exam: Palpation is highly effective at detecting intestinal obstruction in 70-75% of cases.
• Radiography: Loss of intestinal detail, fluid or gas dilation.
• Contrast, Ultrasound, and Percutaneous needle aspirate are used for further diagnosis.

Radiography

• Radiography is 50% diagnostic for intestinal obstruction. Radiography shows loss of intestinal detail, fluid or gas dilation. Contrast is also used in imaging.

Diagnostic Work-up

• Plain radiographs
• Static and dynamic contrast studies
• Endoscopy and biopsy procedures
• Serum gastrin levels

Gastric Neoplasia

• Benign: Benign adenomatous polyps and leiomyomas.
• Malignant: Adenocarcinomas and leiomyosarcomas.
• Lymphoma is more common in cats (LSA) than in dogs (FSA).

Gastric Carcinoma, Symptoms and Etiology

• Symptoms: Vomiting over 1-3 months; hematemesis, melena; anorexia and weight loss
• Etiology: Foreign bodies, intra/extraluminal neoplasms, peptic ulcer disease (e.g., fungal granuloma).

Gastric Carcinoma, Diagnostic Work-up

• Diagnostic Work-up: CBC and biochemical analyses, plain radiographs, static/dynamic contrast studies, endoscopy with biopsy, and serum gastrin levels.

Ulcerated Adenocarcinoma, Body, Gastric Carcinoma

• Ulcerated adenocarcinoma, body and gastric carcinoma images are included in the slide presentation.

Gastric Carcinoma, Prognosis, Treatment and Surgical Procedures.

• Prognosis: Gastric carcinoma generally has a poor prognosis, particularly depending on anatomical location and advanced stage. Gastric lymphoma, particularly small cell lymphoma, often has a better prognosis.
• Treatment: Surgical excision (including regional lymph nodes), neoadjuvant chemotherapy (e.g., doxorubicin/carboplatin), NSAIDS.
• Surgical Procedures:
  • Partial gastrectomy (lesser curvature)
  • Thoracoabdominal (TA) stapler
  • Endoscopic guided surgery
  • Bilroth I/II
  • Pylorectomy, gastroduodenostomy.

Intestinal Tumor Types

• Intussusception.
• Lymphoma
• Carcinoma

Tumor Treatment

• Surgical intervention (excision, including regional lymph nodes).
• Neoadjuvant Chemotherapy (e.g., Doxorubicin).
• Post surgical management and survival times

Other Procedures

• Lymph node biopsy
• Pressure leak testing
• End-to-end anastomosis

Feline Solitary Lymphoma and Intussusception

• Feline solitary lymphoma and intussusception cases are discussed.

Small Intestinal Adenocarcinoma in Cats

• This slide details a study of 32 feline cases.
• Key takeaways included palpation (50%), radiograpic findings (38%), and survival times following biopsy/diagnosis

Canine and Feline Prognosis

• Overall survival rates for canine SI tumors are approximately 40%.
• Median survival time (MST) for various conditions are also presented.

This quiz explores the prevalence and characteristics of intestinal and gastric tumors in dogs and cats. Discover the differences between various tumor types, their commonality, and prognosis in these pets. Gain insights into factors affecting tumor development and classification.