Neoplastic Paneth cells in adenocarcinoma of the stomach: a case report.

A case of well-differentiated (intestinal type) adenocarcinoma of the stomach in a 73-year-old man is reported. The tumor contained Paneth-like cells as an integrated part, and their identity at the light microscopic level was confirmed by histochemical stains including an immunohistochemical stain for lysozyme. This case is unusual, since neoplastic Paneth cells occur only rarely in adenocarcinomas of the stomach.