Adenocarcinoma (; plural adenocarcinomas or adenocarcinomata ) (AC) is a type of
cancerous tumor
A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists ...
that can occur in several parts of the body. It is defined as
neoplasia of
epithelial tissue that has
gland
In animals, a gland is a group of cells in an animal's body that synthesizes substances (such as hormones) for release into the bloodstream ( endocrine gland) or into cavities inside the body or its outer surface ( exocrine gland).
Structure
...
ular origin, glandular characteristics, or both. Adenocarcinomas are part of the larger grouping of
carcinomas, but are also sometimes called by more precise terms omitting the word, where these exist. Thus
invasive ductal carcinoma, the most common form of
breast cancer
Breast cancer is cancer that develops from breast tissue. Signs of breast cancer may include a lump in the breast, a change in breast shape, dimpling of the skin, milk rejection, fluid coming from the nipple, a newly inverted nipple, or ...
, 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.
In the most specific
usage (narrowest
sense
A sense is a biological system used by an organism for sensation, the process of gathering information about the world through the detection of stimuli. (For example, in the human body, the brain which is part of the central nervous system rec ...
), 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
In animals, a gland is a group of cells in an animal's body that synthesizes substances (such as hormones) for release into the bloodstream ( endocrine gland) or into cavities inside the body or its outer surface ( exocrine gland).
Structure
...
, 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, while poorly differentiated adenocarcinomas may not. By
staining the cells from a
biopsy
A biopsy is a medical test commonly performed by a surgeon, interventional radiologist, or an interventional cardiologist. The process involves extraction of sample cells or tissues for examination to determine the presence or extent of a d ...
, a
pathologist can determine whether the tumor is an adenocarcinoma or some other type of cancer. Adenocarcinomas can arise in many tissues of the body owing to the ubiquitous nature of glands within the body, and, more fundamentally, to the
potency of epithelial cells. While each gland may not be secreting the same substance, as long as there is an exocrine function to the cell, it is considered glandular and its malignant form is therefore named adenocarcinoma.
Histopathology
Examples of cancers where adenocarcinomas are a common form:
*
esophageal cancer; most cases in the
developed world are adenocarcinomas.
*
pancreas
The pancreas is an organ of the digestive system and endocrine system of vertebrates. In humans, it is located in the abdomen behind the stomach and functions as a gland. The pancreas is a mixed or heterocrine gland, i.e. it has both an en ...
; over 80% of
pancreatic cancers are ductal adenocarcinomas.
*
prostate cancer
Prostate cancer is cancer of the prostate. Prostate cancer is the second most common cancerous tumor worldwide and is the fifth leading cause of cancer-related mortality among men. The prostate is a gland in the male reproductive system that su ...
is nearly always adenocarcinoma
*
cervical cancer: most is
squamous cell cancer, but 10–15% of cervical cancers are adenocarcinomas
*
stomach cancer: is almost always an adenocarcinoma but in rare cases are
extranodal marginal zone B-cell lymphomas (also termed MALT lymphomas).
Breast
Most
breast cancer
Breast cancer is cancer that develops from breast tissue. Signs of breast cancer may include a lump in the breast, a change in breast shape, dimpling of the skin, milk rejection, fluid coming from the nipple, a newly inverted nipple, or ...
s start in the ducts or
lobules, and are adenocarcinomas. The three most common histopathological types collectively represent approximately three-quarters of breast cancers:
*
Invasive ductal carcinoma: 55% of breast cancers
[Percentage values are from United States statistics 2004. Subtype specific incidences are taken fro]
Table 6
(invasive) an
(in situ) from . These are divided by total breast cancer incidence (211,300 invasive and 55,700 in situ cases) as reported from Breast Cancer Facts & Figures 2003–2004
*
Ductal carcinoma in situ: 13%
[
* Invasive lobular carcinoma: 5%][
]
Colon
The vast majority of colorectal cancers are adenocarcinomas. This is because the colon has numerous glands. Normal colonic glands tend to be simple and tubular in appearance with a mixture of mucus
Mucus ( ) is a slippery aqueous secretion produced by, and covering, mucous membranes. It is typically produced from cells found in mucous glands, although it may also originate from mixed glands, which contain both serous and mucous cells. It ...
-secreting goblet cells and water-absorbing cells. These glands secrete mucus into the lumen of the colon to lubricate the feces as they pass towards the rectum.
When these glands undergo a number of changes at the genetic level, they proceed in a predictable manner as they move from benign to an invasive, malignant colon cancer. In their research paper "Lessons from Hereditary Colorectal Cancer", Vogelstein, et al., suggested that colon cells lose the APC tumor suppressor gene and become a small polyp. Next, they suggested that k-Ras becomes activated and the polyp becomes a small, benign adenoma. The adenoma, lacking the "carcinoma" attached to the end of it, suggests that it is a benign version of the malignant adenocarcinoma. The gastroenterologist uses a colonoscopy to find and remove these adenomas and polyps to prevent them from continuing to acquire genetic changes that will lead to an invasive adenocarcinoma. Vogelstein et al. went on to suggest that loss of the DCC gene and of p53 result in a malignant adenocarcinoma.
There will be a mass of a different color to the surrounding tissue. Bleeding from the tumor is often apparent as the tumor tends to grow blood vessels into it in a haphazard manner via secretion of a number of angiogenesis promoting factors such as VEGF. Histologically, tumours resembling the original structures are classified as well differentiated. Tumour cells that have lost any resemblance to original tissue, both in appearance and structure form, are denoted as poorly differentiated tumour cells. Regardless of the grade, malignant tumors tend to have a large nucleus with prominent nucleoli. There will also be a noticeable increase in the incidence of mitosis, or cell divisions.
Lung
Nearly 40% of lung cancers are adenocarcinomas, which usually originates in peripheral lung tissue. Most cases of adenocarcinoma are associated with smoking; however, among people who have smoked fewer than 100 cigarettes in their lifetimes ("never-smokers"), adenocarcinoma is the most common form of lung cancer. A subtype of adenocarcinoma, the bronchioloalveolar carcinoma, is more common in female never-smokers, and may have a better long-term survival.
This cancer usually is seen peripherally in the lungs, as opposed to small cell lung cancer and squamous cell lung cancer, which both tend to be more centrally located.[ 8th edition.]
Other
* Cholangiocarcinoma, or bile duct cancer
* Vaginal cancer
* Cancer of the urachus
* Stomach cancer
* Prostate cancer
Prostate cancer is cancer of the prostate. Prostate cancer is the second most common cancerous tumor worldwide and is the fifth leading cause of cancer-related mortality among men. The prostate is a gland in the male reproductive system that su ...
Etymology
The term adenocarcinoma is derived from ''adeno-'', meaning "pertaining to a gland", and '' carcinoma'', which describes a cancer that has developed in the epithelial cells.
See also
*
*
References
External links
*
"Adenocarcinoma"
€”NCI Dictionary of Cancer Terms
Surgical Videos, Images and Case Studies of Adenocarcinoma of the Sinuses
{{Authority control
Carcinoma
Infectious causes of cancer