Glandular or mucus-secreting components in squamous cell carcinoma of the esophagus

A review of 195 patients with carcinoma of the esophagus disclosed 41 cases (21.0%) with glandular and/or mucus-secreting components, in addition to the ordinary component of squamous cell carcinoma. These tumors could be grouped into three types according to representative histologic features of glandular and mucus-secreting portions: glandular type (23 cases), cribriform type (11 cases), and mucoepidermoid type (7 cases). The histologic features of the three types were reminiscent of those of adenocarcinoma, adenoid cystic carcinoma, and mucoepidermoid carcinoma of salivary glands, respectively. Moreover, areas showing glandular or mucus-secreting differentiation were in greater part located in the submucosa and the lamina propria mucosae, thereby suggesting that such differentiation had arisen in the esophageal glands or their ducts. In all 41 cases, the ordinary element of squamous cell carcinoma, invasive, or noninvasive, was admixed in various proportions with the glandular components, indicating that this type of esophageal tumor had originated not only from the covering squamous epithelium but also from esophageal mucous-gland or ductal epithelium. The findings also support the concept of the field origin of carcinogenesis in esophageal carcinoma.