Adenocarcinoma

Adenocarcinoma is a type of cancer. The medical term for it is a malignant neoplasm, and malignant here simply means cancerous. It starts in epithelial cells, the cells that line the body's surfaces, both outside and inside. That places it in the family of carcinomas, the name given to cancers of these lining cells.

But it doesn't start in just any lining cell. It starts in the epithelial cells of glands, the ones that make something: fluids or mucus. The tissues where these cells live are sometimes called glandular tissues. Picture the lining of an organ as a tiled floor where, here and there, a few of the tiles are tiny fountains that release fluid. Adenocarcinoma starts in the cells of those fountains, or of structures that resemble them. And when the tissue is examined under a microscope, what usually makes it recognizable is exactly that: structures shaped like glands.

It can show up in many parts of the body. Common sites include the breast, the lung, the prostate (a gland in the male reproductive system), and the digestive system, meaning the organs that process food: the esophagus, the tube that carries food to the stomach; the stomach itself; the pancreas, which makes digestive juices; and the colon and rectum, the last part of the intestine. These organs are very different, but what these cancers share is where they come from: epithelial cells of glands or of gland-like structures.