Oat cell carcinoma of the esophagus.

A case of oat cell carcinoma of the esophagus is reported. The tumor cells were argyrophilic and electron microscopic examination showed that they contained dense-core granules typical of oat cell carcinoma of the lung and other sites. It is concluded that primary oat cell carcinoma of the esophagus is a recognizable entity derived from argyrophil cells in the esophageal mucosa. The existence of rare esophageal carcinomas with both oat cell and squamoid features is noted and their possible histogenesis is discussed.