Esophageal cancers comprise cancers of different histological types with diverse cellular and molecular bases. The major histological types of esophageal cancers are squamous cell carcinoma and adenocarcinoma. It is important to note that there are histological variants of squamous cell carcinoma and adenocarcinoma such as basaloid squamous cell carcinoma, spindle cell carcinoma, mucoepidermoid carcinoma, and adenosquamous carcinoma. In addition, neuroendocrine neoplasms such as small cell carcinoma of the esophagus account for approximately 1 % of primary esophageal carcinoma. All these carcinomas have distinct clinicopathological features. Limited studies have revealed that the cellular and molecular biology of these uncommon types of esophageal carcinomas are different from those of esophageal squamous cell carcinoma or adenocarcinoma.