Carcinoma
Cancer that begins in the skin or in tissues that line or cover internal organs.
More on carcinomas at NCI.
Adenocarcinoma
Cancer that begins in glandular (secretory) cells. Glandular cells are found in tissue that lines certain internal organs and makes and releases substances in the body, such as mucus, digestive juices, or other fluids. Most cancers of the breast, pancreas, lung, prostate, and colon are adenocarcinomas.
Pronunciation and more information at NCI.