Abstract
We report here our experience with six rare cases of primary adenosquamous carcinoma of the stomach and colon. Gastric carcinoma appearing as adenosquamous carcinoma was found in two patients. They were type 2 carcinoma of MA, sei ; and type 3 carcinoma of MC, ssjS. Carcinoma of the colon appearing as adenosquamous carcinoma was found in 4 patients. They were type 1 carcinoma of Rs, ss ; type 4 carcinoma of D, s ; type 2 carcinoma of S, ss ; and type 2 carcinoma of D, ss. Clinicohistopathological study was performed on these six patients. With respect to the mechanism of onset of adenosquamous carcinoma, it was presumed that squamous cell carcinoma was induced by squamous epithelial metaplasia in the adenocarcinoma, because histological analysis revealed adenocarcinoma and squamous cell carcinoma collocated in the same glandular epithelial duct, and PASIAIcian-blue stain positive intestinal mucus was observed at the site of the squamous cell carcinoma. These findings indicate that squamous cell carcinoma is a secondary modification of adenocarcinoma.
