+ Biologic Behavior

  • Intestinal LSA is the most common intestinal tumor
  • Majority are multifocal and involve the small intestine


+ Clinical Signs

  • Anorexia
  • Weight loss
  • Intermittent vomiting
  • Diarrhea
  • Severe, persistent vomiting is occasionally observed if proximal small intestinal tumor causes obstruction


+ Physical Examination

  • Palpable abdominal mass and cachexia are common
  • Other findings include dehydration and abdominal pain

+ Laboratory Tests

  • Mesenchymal tumors are associated with microcytic hypochromic anemia, hypoproteinemia, and mild leukocytosis

+ Abdominal Radiographs

  • Abdominal mass, obstruction, or persistent irregularity of bowel appearance are identified in 25% of small intestinal tumors and nearly 50% of non-lymphoid intestinal tumors
  • Abdominal mass is detected in 60% of canine mesenchymal small intestinal tumors

+ Contrast Radiography

Contrast Radiographs: Mural lesions include luminal filling defect, intestinal wall thickening, mucosal ulceration, abnormal positioning of intestinal loops, and constricting annular lesions

+ Ultrasonography

  • Intestinal mass identified in 87% (13/15) dogs with non-lymphoid small intestinal tumors
  • Loss of wall layering is an excellent predictive factor for differentiating intestinal neoplasia from enteritis in dogs (99% v 12%) with intestinal tumors 50.9-times more likely to have loss of wall layering
  • Intestinal tumors also have significant increases intestinal wall thickness (15 mm v 6 mm) and are significantly less likely to have diffuse intestinal involvement (2% v 72%)

+ Exploratory Celiotomy

Definitive diagnosis with exploratory celiotomy and biopsy


+ Surgery

  • Debilitation and hypoproteinemia may complicate treatment
  • Exploratory celiotomy with resection and end-to-end anastomosis with 4-8 cm margins and serosal patching
  • Mesenteric and regional lymph nodes should be assessed ± aspirated

+ Chemotherapy

Multiagent protocols recommended for LSA as either adjuvant therapy or sole treatment for diffuse disease