adenocarcinoma

thumb|250px|Micrograph showing typical features of adenocarcinoma on [[cytopathology (Pap stain). Vacuoles are more prominent in mucinous tumors but can be seen in serous tumors as well.]]

Adenocarcinoma (AC) is a type of cancer made of cells from glands. They can occur in many parts of the body. Adenocarcinomas are part of the larger grouping of carcinomas, but are also sometimes called by more precise terms omitting the word, where these exist. Adenocarcinomas are defined as neoplasia of epithelial tissue that has glandular origin or glandular characteristics. Thus invasive ductal carcinoma, the most common form of breast cancer, is adenocarcinoma but does not use the term in its name. However, esophageal adenocarcinoma does, to distinguish it from the other common type of esophageal cancer, esophageal squamous cell carcinoma. Several of the most common forms of cancer are adenocarcinomas, and the various sorts of adenocarcinoma vary greatly in all their aspects, so that few useful generalizations can be made about them.