Six Cases of So-Called Carcinosarcoma of the Esophagus -- Histological and Ultrastructural Study on its Histogenesis --

Histopathological aspects of six cases of so-called carcinosarcomaof the esophagus are reported. Four of the patients had polypoidtumors and the other two had ulcerated lesions. Histologically,every tumor in the six cases was composed of both carcinomatousand "sarcoma-like" elements. The carcinomatous element was squamouscell carcinoma in five cases and anaplastic carcinoma in thesixth. The "sarcoma-like" element was "sarcomatous" proliferationof spindle cells. Histologically transitional features betweencarcinomatous and "sarcoma-like" components were observed inevery tumor. Electron microscopic study of semi-serial sectionsadjacent to toluidine blue-stained histological sections revealedthat the spindle-shaped cells in the "sarcoma-like" tissue wereof squamous epithelial cell origin. Therefore, these findingsled to a conclusion that so-called carcinosarcoma of the esophagusof the six cases was carcinoma associated with "sarcomatous"proliferation of carcinoma cells.