View source for Adenocarcinoma

{{Short description|Cancer of epithelial cells with glandular origin or characteristics}}
{{Infobox medical condition
| name            = Adenocarcinoma
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| image           = Histopathology of adenocarcinoma.png
| caption         = [[Histopathology]] of typical features of adenocarcinoma on [[H&E stain]], but in reality the visual features vary substantially, both by subtypes of adenocarcinoma as well as between individual cases.
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| field           = [[Oncology]], [[Pathology]]
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[[File:Pap stain of adenocarcinoma in peritoneal fluid.png|thumb|250px|[[Micrograph]] showing typical features of adenocarcinoma on [[cytopathology]] ([[Pap stain]]). Vacuoles are more prominent in [[mucinous neoplasm|mucinous]] tumors but can be seen in [[serous tumor]]s as well.]]
'''Adenocarcinoma'''<ref>From ''[[wikt:adeno-|adeno-]]'', "gland" and ''[[wikt:καρκίνος|karkin(o)-]]'', "cancerous" and ''[[wikt:-oma|-oma]]'', "tumor".</ref> ({{IPAc-en|ˌ|æ|d|ɪ|n|oʊ|k|ɑːr|s|ɪ|ˈ|n|oʊ|m|ə}}; plural '''adenocarcinomas''' or '''adenocarcinomata''' {{IPAc-en|ˌ|æ|d|ɪ|n|oʊ|k|ɑːr|s|ɪ|ˈ|n|oʊ|m|ə|t|ə}}; '''AC''') is a type of [[cancerous]] [[tumor]] that can occur in several parts of the body. It is defined as [[neoplasia]] of [[epithelium|epithelial]] tissue that has [[gland]]ular origin, glandular characteristics, or both. Adenocarcinomas are part of the larger grouping of [[carcinoma]]s, 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]], 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, the glandular origin or traits are [[exocrine gland|exocrine]]; [[endocrine system|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 tumor]]s. 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 layer]]s ([[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 [[malignancy|malignant]] counterpart to [[adenoma]], which is the [[benignity|benign]] form of such [[neoplasm|tumors]]. Sometimes adenomas [[malignant transformation|transform]] into adenocarcinomas, but most do not.

Well-[[cellular differentiation|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 [[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 [[cell potency|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==
[[File:Seborrheic keratosis on human back.jpg|thumb|upright|Many [[seborrheic keratoses]] on back of person with [[Leser–Trélat sign]] due to [[colon cancer]]]]

Examples of cancers where adenocarcinomas are a common form:
* [[esophageal cancer]]; most cases in the [[developed world]] are adenocarcinomas.<ref name=WCR2014>{{cite book|title=World Cancer Report 2014.|date=2014|publisher=World Health Organization|isbn=978-92-832-0429-9|pages=Chapter 5.3}}</ref>
* [[pancreas]]; over 80% of [[pancreatic cancer]]s are ductal adenocarcinomas.<ref>{{cite journal | vauthors = Bond-Smith G, Banga N, Hammond TM, Imber CJ | title = Pancreatic adenocarcinoma | journal = BMJ | volume = 344 | pages = e2476 | date = May 2012 | pmid = 22592847 | doi = 10.1136/bmj.e2476 | s2cid = 206894869 }}</ref>
* [[prostate cancer]] is nearly always adenocarcinoma
* [[cervical cancer]]: most is [[squamous cell cancer]], but 10–15% of cervical cancers are adenocarcinomas<ref>{{cite book|title=World Cancer Report 2014.|date=2014|publisher=World Health Organization|isbn=978-92-832-0429-9|pages=473–474}}</ref>
* [[stomach cancer]]: is almost always an adenocarcinoma but in rare cases are [[Marginal zone B-cell lymphoma#Extranodal marginal zone lymphoma|extranodal marginal zone B-cell lymphomas]] (also termed MALT lymphomas).<ref name="pmid28151409">{{cite journal | vauthors = Burkitt MD, Duckworth CA, Williams JM, Pritchard DM | title = Helicobacter pylori-induced gastric pathology: insights from in vivo and ex vivo models | journal = Disease Models & Mechanisms | volume = 10 | issue = 2 | pages = 89–104 | date = February 2017 | pmid = 28151409 | pmc = 5312008 | doi = 10.1242/dmm.027649 }}</ref>

===Breast===
Most [[breast cancer]]s start in the ducts or [[Lobe (anatomy)|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<ref name=USA-2004>Percentage values are from United States statistics 2004. Subtype specific incidences are taken from [https://archive.today/20130223233954/http://cebp.aacrjournals.org/content/18/6/1763/T6.expansion.html Table 6] (invasive) and [https://archive.today/20130223054758/http://cebp.aacrjournals.org/content/18/6/1763/T3.expansion.html Table 3] (in situ) from {{cite journal | vauthors = Eheman CR, Shaw KM, Ryerson AB, Miller JW, Ajani UA, White MC | title = The changing incidence of in situ and invasive ductal and lobular breast carcinomas: United States, 1999-2004 | journal = Cancer Epidemiology, Biomarkers & Prevention | volume = 18 | issue = 6 | pages = 1763–1769 | date = June 2009 | pmid = 19454615 | doi = 10.1158/1055-9965.EPI-08-1082 | doi-access = free }}. 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 {{cite web|url=http://www.cancer.org/docroot/stt/content/stt_1x_breast_cancer_facts__figures_2003-2004.asp |title=  Breast Cancer Facts & Figures 2003-2004 |access-date=2010-06-15 |url-status=dead |archive-url=https://web.archive.org/web/20090415173047/http://www.cancer.org/docroot/STT/content/STT_1x_Breast_Cancer_Facts__Figures_2003-2004.asp |archive-date=2009-04-15 }}</ref>
* [[Ductal carcinoma in situ]]: 13%<ref name=USA-2004/>
* [[Invasive lobular carcinoma]]: 5%<ref name=USA-2004/>

===Colon===
[[Image:Colon cancer.jpg|thumb|right|[[gross examination|Gross]] appearance of an opened [[colectomy]] specimen containing two [[Colorectal polyp|adenomatous polyps]] (the brownish oval tumors above the labels, attached to the normal beige lining by a stalk) and one '''invasive [[colorectal cancer|colorectal]] [[carcinoma]]''' (the crater-like, reddish, irregularly-shaped tumor located above the label)]]
[[File:Well-, moderately and poorly differentiated colorectal adenocarcinoma.png|thumb|300px|[[Histopathology]] of well-, moderately and poorly differentiated colorectal adenocarcinoma.]]

The vast majority of [[colorectal cancer]]s are adenocarcinomas. This is because the [[Colon (anatomy)|colon]] has numerous glands. Normal colonic glands tend to be simple and tubular in appearance with a mixture of [[mucus]]-secreting [[goblet cells]] and water-absorbing cells. These glands secrete mucus into the [[lumen (anatomy)|lumen]] of the colon to lubricate the feces as they pass towards the rectum.<ref>{{cite book |vauthors=Heath JE, Young B, Wheater PR, Lowe JN, Stevens A |title=Wheater's Functional histology: a text and colour atlas |url=https://archive.org/details/wheatersfunction00youn |url-access=limited |publisher=Churchill Livingstone Elsevier |location=Edinburgh |edition=5th |year=2006 |page=[https://archive.org/details/wheatersfunction00youn/page/n636 283] |isbn=978-0-443-06850-8 }}</ref>

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 [[Adenomatous polyposis coli|APC]] tumor suppressor gene and become a small polyp. Next, they suggested that [[KRAS|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 [[Deleted in Colorectal Cancer|DCC]] gene and of [[p53]] result in a malignant adenocarcinoma.<ref>{{cite journal | vauthors = Kinzler KW, Vogelstein B | title = Lessons from hereditary colorectal cancer | journal = Cell | volume = 87 | issue = 2 | pages = 159–170 | date = October 1996 | pmid = 8861899 | doi = 10.1016/S0092-8674(00)81333-1 | s2cid = 18032613 | doi-access = free }}</ref>

===Lung===
{{main|Adenocarcinoma of the lung}}
[[File:Pie chart of lung cancers.svg|thumb|Pie chart showing incidence of adenocarcinoma of the lung (shown in yellow) as compared to other [[lung cancer]] types, with fractions of non-smokers versus smokers shown for each type<ref>Smokers defined as current or former smoker of more than 1 year of duration. See [[Commons:File:Pie chart of lung cancers.svg|image page in Commons]] for percentages in numbers. Reference:
* [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3044470/table/T2/ Table 2] in: {{cite journal | vauthors = Kenfield SA, Wei EK, Stampfer MJ, Rosner BA, Colditz GA | title = Comparison of aspects of smoking among the four histological types of lung cancer | journal = Tobacco Control | volume = 17 | issue = 3 | pages = 198–204 | date = June 2008 | pmid = 18390646 | pmc = 3044470 | doi = 10.1136/tc.2007.022582 }}</ref>]]

Nearly 40% of lung cancers are adenocarcinomas, which usually originates in peripheral lung tissue.<ref>{{cite book | vauthors = Lu C, Onn A, Vaporciyan AA, Chang JY, Glisson BS, Komaki R, Wistuba II, Roth JA, Herberst RS | title=Holland-Frei Cancer Medicine | edition=8th | chapter=78: Cancer of the Lung | publisher=People's Medical Publishing House | year=2010 |isbn=978-1-60795-014-1 }}</ref> Most cases of adenocarcinoma are associated with smoking; however, among people who have smoked fewer than 100 cigarettes in their lifetimes ("never-smokers"),<ref>{{Cite book | vauthors = Horn L, Pao W, Johnson DH  | title=Harrison's Principles of Internal Medicine | publisher=McGraw-Hill | veditors = Longo DL, Kasper DL, Jameson JL, Fauci AS, Hauser SL, Loscalzo J | year=2012 | chapter=Chapter 89 | edition=18th | isbn=978-0-07-174889-6 }}</ref> adenocarcinoma is the most common form of lung cancer.<ref>{{cite journal | vauthors = Subramanian J, Govindan R | title = Lung cancer in never smokers: a review | journal = Journal of Clinical Oncology | volume = 25 | issue = 5 | pages = 561–570 | date = February 2007 | pmid = 17290066 | doi = 10.1200/JCO.2006.06.8015 }}</ref> A subtype of adenocarcinoma, the [[bronchioloalveolar carcinoma]], is more common in female never-smokers, and may have a better long-term survival.<ref>{{cite journal | vauthors = Raz DJ, He B, Rosell R, Jablons DM | title = Bronchioloalveolar carcinoma: a review | journal = Clinical Lung Cancer | volume = 7 | issue = 5 | pages = 313–322 | date = March 2006 | pmid = 16640802 | doi = 10.3816/CLC.2006.n.012 }}</ref>

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.<ref name=Kumar-adenocarcinoma>{{cite book | chapter = Chapter 13, box on morphology of adenocarcinoma | vauthors = Mitchell RS, Kumar V, Abbas AK, Fausto N |title=Robbins Basic Pathology|publisher=Saunders |location=Philadelphia |isbn=978-1-4160-2973-1 |year=2007 }} 8th edition.</ref><ref>{{cite journal | vauthors = Travis WD, Travis LB, Devesa SS | title = Lung cancer | journal = Cancer | volume = 75 | issue = 1 Suppl | pages = 191–202 | date = January 1995 | pmid = 8000996 | doi = 10.1002/1097-0142(19950101)75:1+<191::AID-CNCR2820751307>3.0.CO;2-Y | s2cid = 34718856 }}</ref>

===Other===
* [[Cholangiocarcinoma]], or [[bile duct]] cancer
* [[Vaginal cancer]]
* Cancer of the [[urachus]]
* [[Stomach cancer]]
* [[Prostate cancer]]

== See also ==
* {{annotated link|Clear-cell adenocarcinoma}}
* {{annotated link|Fetal adenocarcinoma}}

== References ==
{{Reflist}}

== External links ==
* {{commons category-inline}}
* [http://www.cancer.gov/dictionary?cdrid=46216 "Adenocarcinoma"]—NCI Dictionary of Cancer Terms
* [http://www.sinustumor.org/tumors/adenocarcinoma/ Surgical Videos, Images and Case Studies of Adenocarcinoma of the Sinuses]
{{Medical resources
| ICD10           =
| ICD9            = {{ICD9|151.0}}, {{ICD9|182.0}}
| ICDO            = {{ICDO|8140|3}}
| OMIM            =
| OMIM_mult       =
| MedlinePlus     =
| eMedicineSubj   =
| eMedicineTopic  =
| DiseasesDB      =
| MeshID          = D000230
| SNOMED CT       = 35917007
|ICD11={{ICD11|2D40}}, {{ICD11|XH2L30}}, {{ICD11|XH74S1}}}}{{Epithelial neoplasms}}
{{Respiratory neoplasia}}
{{Digestive system neoplasia}}
{{Female genital neoplasia}}
{{Male genital neoplasia}}
{{Authority control}}

[[Category:Carcinoma]]
[[Category:Infectious causes of cancer]]