2017 Volume 91 Issue 1 Pages 94-97
A 75-year-old male presented with black stool and severe anemia. Upper gastrointestinal endoscopic examination revealed a 10-cm large exophytic tumor on the upper posterior wall of the stomach, which was not found in an examination 2 years before. Biopsy specimens showed an undifferentiated sarcoma or carcinosarcoma. A total gastrectomy was performed for bleeding management. Histological findings revealed that most of the tumor was composed of various atypical cells such as polygonal, elliptical, and spindle-shaped cells, and differentiation into specific mesenchymal tissue was not observed. In the immunohistological study, the mesenchymal marker was negative, whereas the epithelial marker such as cytokeratin (AE1/AE3) was positive in some cells. Based on these results, the tumor was diagnosed as gastric sarcomatoid carcinoma. Gastric sarcomatoid carcinoma is a rare disease, and much is unknown about its development process. In this case, as a part of sarcoma-like components was positive in the epithelial marker, we speculated that an epithelial malignant tumor had changed to a sarcoma-like lesion. Because endoscopic follow-up of rapid progression of gastric carcinosarcoma has not been reported yet, the present case is considered valuable.
