Simultaneous primary carcinomas--a report of three cases.

Two separate primary carcinomas occurring simultaneously in the esophagus and stomach are uncommon. The authors report three cases of this entity, squamous cell carcinoma of the osophagus and adenocarcinoma of the stomach, one of which is classified as a collision carcinoma of the stomach. Because of the rarity of collision tumors of this histologic variety, the world literature was reviewed. Diagnostic features and the relative prognosis of dual primary carcinomas are discussed.