Leiomyosarcoma of the esophagus. Report of two cases, one with associated squamous cell carcinoma.

Two new cases of leiomyosarcoma of the esophagus, one with an associated intraepithelial squamous cell carcinoma with foci of microinvasion, are presented and the literature is reviewed. Electron microscopic findings are presented with emphasis on features which may be helpful in determining the malignant potential of smooth muscle tumors, a determination which is often difficult at the light microscopic level. The literature regarding the association of leiomyosarcoma with epithelial malignancy in the gastrointestinal tract is reviewed, and the impression that this is a highly unusual occurrence is supported.