+ General Considerations
- ADC and LSA are the most common large intestinal tumors in cats
- Other large intestinal tumors include MCT, HSA, and neuroendocrine carcinoma
- Intestinal HSA metastatic to regional lymph nodes and carcinomatosis has been reported
- Ileocolic junction most common site for large intestinal tumors
+ Clinical Signs
Hematochezia, vomiting, and weight loss
Diagnosis
+ Physical Examination
- Cachexia is common
- Abdominal mass is frequently palpable via either abdomen and rectal palpation
- Other findings include dehydration and abdominal pain
+ Ultrasonography
Circumferential transmural thickening with loss of normal intestinal layering reported in 5 cats with intestinal ADC
+ Endoscopy
- Endoscopy is recommended prior to definitive treatment
- Biopsy samples should be interpreted histologically as cytologic misdiagnosis is common with intestinal ADC being misdiagnosed as either septic inflammation or LSA
- Biopsy samples are often small and superficial resulting in false-negative diagnosis if lesion is either submucosal or associated with surface ulceration and necrosis
+ Exploratory Celiotomy
- Definitive diagnosis with exploratory celiotomy and biopsy
- Feline large intestinal ADC more commonly associated with mucosal ulceration and bowel thickening than annular stenosis
- Leiomyoma and sarcoma are usually large solitary masses growing through the intestinal serosa
TREATMENT
+ Surgery
- Debilitation and hypoproteinemia may complicate treatment
- Exploratory celiotomy with resection and end-to-end anastomosis with 4-8 cm margins and serosal patching of anastomosis
- 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
- Chemotherapy is also recommended for cats with intestinal plasmacytoma and MCT
- No effective chemotherapy for ADC
+ Prognosis
- MST for cats with colonic tumors is significantly better with:
- Surgical resection compared to conservative management (198 days v 22 days)
- MCT compared to LSA (199 days v 97 days)
- No metastasis in cats with ADC (49 days v 259 days)
- However, some cats with metastatic disease had prolonged survival time