The esophagus (ĕ-sof´ah-gus) is the hollow, muscular tube that moves food and liquid from the mouth to the stomach. The wall of the esophagus is made up of several layers of tissue, including muscle, connective tissue that supports the framework of the body, and an inner lining called the mucosa.
Cancer of the esophagus (also called esophageal cancer) starts in the inner layer (the mucosa) and grows outward (through the submucosa and the muscle layer). Since 2 types of cells can line the esophagus, there are 2 main types of esophageal cancer:
The esophagus is normally lined with squamous cells. Cancer starting in these cells is called squamous cell carcinoma. This type of cancer can occur anywhere along the esophagus, but is most common in the portion of the esophagus located in the neck region and in the upper two-thirds of the chest cavity.
Cancers that start in gland cells (cells that make mucus) are called adenocarcinomas.This type of cancer usually occurs in the distal (lower third) part of the esophagus. Before an adenocarcinoma can develop, gland cells must replace an area of squamous cells, which is what happens in Barrett’s esophagus. This occurs mainly in the lower esophagus, which is where most adenocarcinomas start.