Carcinosarcoma and sarcomatoid carcinoma of the stomach: Two case reports

RATIONALE: Carcinosarcoma and sarcomatoid carcinoma of the stomach are rare, malignant, and biphasic tumors with high mortality. The differential diagnosis of these 2 diseases remains challenging. In the present study, we present 2 cases of carcinosarcoma and sarcomatoid carcinoma of the stomach. PATIENT CONCERNS: A 54-year-old woman was admitted with complaints of epigastric pain for 4 months, but she became serious for 10 days accompanied by melena. A 75-year-old man was admitted with complaints of epigastric pain for 1 month. DIAGNOSIS: The female had a Borrmann type III irregular ulcerative lesion (5.0 × 4.0 × 1.0 cm) originating from the gastric antrum. The male had Borrmann type I tumor polypoid exophytic (5.0 × 4.0 × 2.0 cm) in the fundus of stomach near the cardia. Both cases were identified as malignant neoplasms by endoscopic biopsy and further confirmed by performing laparoscopic proximal gastrectomy, esophagogastrostomy, and palliative distal subtotal gastrectomy. The postoperative histopathological morphology and immunohistochemistry studies revealed sarcomatoid carcinoma for the female and gastric carcinosarcoma for the male respectively. INTERVENTIONS: The female patient subsequently underwent laparoscopy-assisted radical distal gastrectomy for gastric cancer followed by systemic chemotherapy with oxaliplatin plus tegafur. The male patient underwent laparoscopic proximal gastrectomy and esophagogastrostomy were performed. OUTCOMES: The female had a mixture of a little poorly-differentiated adenocarcinoma and abundant sarcomatoid spindle cell elements, and is still alive healthy up to date for 2 and a half years after surgery by phone follow-up. The male patient had both adenocarcinoma and fibrosarcoma in a single tumor, and died 1 month after the operation. LESSONS: The present study provides insight into the clinical findings, differential diagnosis, and prognosis of carcinosarcomas and sarcomatoid carcinomas of the stomach. More cases are needed for further studies in the future.