Adenocarcinoma
Adenocarcinoma (
adeno-, "gland" and
karkin(o)-, "cancerous" and
-oma, "tumor") (/ˌædɨnoʊkɑrsɨˈnoʊmə/; plural
adenocarcinomas or
adenocarcinomata /ˌædɨnoʊkɑrsɨˈnoʊmɨtə/) is neoplasia of epithelial tissue that has glandular origin, glandular characteristics, or both. In the most specific usage (narrowest sense), the glandular origin or traits are exocrine; endocrine gland tumors, such as a VIPoma, an insulinoma, or a pheochromocytoma, are typically not referred to as adenocarcinomas but rather are often called neuroendocrine tumors. Epithelial tissue sometimes includes, but is not limited to, the surface layer of skin, glands, and a variety of other tissue that lines the cavities and organs of the body. Epithelial tissue can be derived embryologically from any of the germ layers (ectoderm, endoderm, or mesoderm). To be classified as adenocarcinoma, the cells do not necessarily need to be part of a gland, as long as they have secretory properties. Adenocarcinoma is the malignant counterpart to adenoma, which is the benign form of such tumors. Sometimes adenomas transform into adenocarcinomas, but most do not.