So-called carcinosarcoma of the esophagus: A clinicopathologic, immunohistochemical and DNA flow-cytometric analysis of 6 cases

Six cases of carcinosarcoma of the esophagus were studied clinicopathologically, immunohistochemically and with DNA flow cytometry. Transitional areas with morphology intermediate between carcinoma and sarcoma were found microscopically in all cases. Immunohistochemically, the carcinomatous areas contained keratin-positive cell components in all cases while vimentin-positive cells were found in sarcomatous areas in 5 cases. By DNA flow analysis of microdissection, the sarcomatous components of the tumors showed an aneuploid pattern with one exception, in contrast the carcinomatous components were diploid in all cases. In these few cases, PCNA, S-phase fraction and the mitotic rate were extremely high, apparently indicating a correlation with malignant behavior. Accordingly, examination by immunohistochemistry and DNA ploidy is useful fbr the analysis of biological properties in the so-called carcinosarcoma of the esophagus.