Adenocarcinoma is a type of cancerous tumor that can occur in several organs of the body.
It is a neoplasia of epithelial tissue that has glandular origin,
Invasive ductal carcinoma, the most common form of breast cancer, is adenocarcinoma.
Several of the most common forms of cancer are adenocarcinomas.
In its most specific usage 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.
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.
Well differentiated adenocarcinomas tend to resemble the glandular tissue that they are derived from.
Poorly differentiated adenocarcinomas may not resemble tissue of organ origin.
Regardless of the grade, malignant tumors tend to have a large nucleus with prominent nucleoli.
There is a noticeable increase in the incidence of mitosis, or cell divisions.
Cancers where adenocarcinomas are a common:
esophageal cancer; most cases in the developed world are adenocarcinomas.
pancreas; over 80% of pancreatic cancers are ductal adenocarcinomas.
prostate cancer is nearly always adenocarcinoma
cervical cancer: 10–15% of cervical cancers are adenocarcinomas.
stomach cancer: is almost always an adenocarcinoma.
Breast
Colorectal
Lung
Cholangiocarcinoma, or bile duct cancer
Vaginal cancer
Cancer of the urachus