Pseudosarcoma and carcinosarcoma of the esophagus.

Two cases of polypoid carcinoma with pseudosarcoma and one of so-called carcinosarcoma of the esophagus are presented. The clinical and morphologic characteristics of these tumors are described and the literature is reviewed. It is postulated that pseudosarcomas and so-called carcinosarcomas belong essentially to the same pathologic entity because of their similar morphologic and biologic aspects. The histogenesis of the sarcoma-like elements of these tumors support the theory of epithelial origin on the basis of the sarcoma-like transformation of squamous cell carcinoma and of the presence of epithelial elements in the "sarcomatous" areas.