Polypoid adenosquamous carcinoma of the esophagus with prominent spindle cells. Report of a case with immunohistochemical and ultrastructural studies.

We report a case of spindle-cell adenosquamous carcinoma of the esophagus. This represents the third case in the worldwide literature in which an esophageal polypoid tumor contains adenosquamous carcinoma rather than the usual squamous cell carcinoma in addition to a prominent spindle-cell element. The spindle-cell component displayed positive immunoreaction for both keratin and vimentin, as expression of bidirectional differentiation within a single neoplasm.