Gastric tumors are rare in both cats and dogs. The majority of gastric tumors are malignant and include lymphoma (especially cats), adenocarcinoma and leiomyosarcoma, but benign tumors have also been reported such as extramedullary plasmacytoma and leiomyoma. The metastatic risk for malignant tumors is moderate to high with metastasis to the regional lymph nodes, liver and lungs relatively common.
Ultrasonography is recommended for both diagnosis and clinical staging. Other diagnostic tests include contrast radiographs (barium study) and endoscopy. A preoperative diagnosis is sometimes not possible and surgery may be required to both diagnose and treat gastric tumors.
An abdominal ultrasound is recommended to check for metastasis to the regional lymph nodes and liver. Chest radiographs or CT scans are done to check for metastasis to the lungs.
The majority of gastric tumors are treated with surgical excision with wide margins (3-5 cm). The location of the tumor will determine if surgical resection is possible and, if so, what surgical procedure is recommended. For instance, simple closure is possible following excision of lesser curvature tumors, but more complicated reconstructive procedures (Bllroth I or II) may be required for pyloric antral tumors.
Lymphoma can be treated with multiagent chemotherapy protocols, but surgery is often required for definitive diagnosis and perhaps treatment of solitary gastric lymphomas.
The prognosis is dependent on tumor type. The prognosis for gastric carcinomas is poor with most survival times < 6 months, whereas many dogs with gastric leiomyosarcomas can be cured with surgical resection alone with a median survival time of 21 months and a 2-year survival rate of 66%. The median survival time following treatment of cats with gastric lymphoma with a Madison-Wisconsin chemotherapy protocol is 40 weeks. Benign gastric tumors, such as extramedullary plasmacytomas and leiomyomas, can be cured with surgical excision.
To be updated