Polypoid squamous carcinoma of the esophagus. Report of a case and its implications for the histogenesis of “carcinosarcoma” of the esophagus

A case of polypoid carcinoma of the esophagus is reported. The few previously reported cases had been discredited on the basis of their paucity of histopathological description and the lack of photomicrographic evidence. Microscopic examination revealed that the lesion was an undifferentiated squamous carcinoma. The surface of the tumor displayed small areas of “loose” chronically inflamed connective tissue in which the metaplastic transformation of the typical large round cells to spindle-shaped cells could be observed. So-called “carcinosarcoma” of the esophagus is typically polypoid. Some controversy had arisen over the theory that proposed an epithelial origin for the spindle-shaped cells of these tumors. The confirmation of a polypoid esophageal carcinoma supports this theory. The author concludes that the finding of minimal spindle cell metaplasia in the present case further strengthens the argument that the “sarcomatous” cells of many “carcinosarcomas” are metaplastic derivatives of epithelial cells.