[A case of adenoid cystic carcinoma of the esophagus].

A surgical case of an adenoid cystic carcinoma (ACC) of the esophagus in a 75-year-old man is reported. Histologically, the tumor consisted of an ACC, a squamous cell carcinoma and a small tubular adenocarcinoma. The ACC and the tubular adenocarcinomatous regions in the submucosa and the lamina propria were continuous with the overlying squamous cell carcinoma and atypical squamous epithelium. Immunohistochemically, two types of tumor cells were detected in the ACC. One was found to have EMA-positive epithelial cells whereas the other had actin-positive myoepithelial cells. In the normal esophageal gland, actin-positive cells are found at the periphery of acini and around the layer of epithelial cells in the small duct but they have not been detected in the main duct. These findings suggest that the tumor developed from the small duct and differentiated into two directions: an ACC and a squamous cell carcinoma.