An Uncommon Presentation of Carcinosarcoma of the Stomach and a Minimally Invasive Approach for Treatment

Carcinosarcoma is a rare malignant neoplasm that is composed of both epithelial and mesenchymal tumor components. Gastric carcinosarcoma is even more rare and is often diagnosed at a late stage. In this report, we investigate a case of early gastric carcinosarcoma with regional lymph node metastasis in a 78-year-old woman. The patient underwent partial gastrectomy, lymphadenectomy, and splenectomy. The tumor was confined to the gastric submucosa, and a biopsy specimen led to a histological diagnosis of carcinosarcoma with adenocarcinoma, squamous-cell carcinoma, and undifferentiated pleomorphic sarcoma components. Metastasis was present in one lymph node and displayed osteosarcomatous differentiation. Vigilant monitoring for recurrence and metastatic disease will be required for this patient.