Generality
Adenoma is a benign tumor that originates in a tissue with secretory properties (glands and mucous membranes) and / or which takes on the appearance of a gland.
Specifically, adenomas can originate from epithelial cells of the exocrine glandular organs (for example, pituitary glands, thyroid glands, breasts, adrenal glands, parathyroid glands, etc.) or from epithelial cells of tissues with secretory properties (for example mucous lining the esophagus, stomach or colon).
The most common human adenoma is colon adenoma, better known as intestinal polyp.
The diagnosis of adenoma is based on a biopsy (or bioptic examination): the latter allows us to understand whether the tumor mass is benign (adenoma) or malignant (adenocarcinoma).
Differences between a benign tumor and a malignant tumor
In medicine, the word " tumor " or " neoplasm " indicates a mass of abnormal cells, which have a growth rate and division greater than normal cells.
A benign tumor is a neoplasm with a relatively low rate of growth, low infiltration power and an equally poor (if not zero) metastasizing power.
On the contrary, a malignant tumor is a neoplasm with a very considerable growth rate, a high infiltration power and a high metastasizing power.
Please note: due to infiltrative power, this refers to the ability to affect adjacent anatomical regions.
With metastasizing power, on the other hand, reference is made to the ability of cancer cells to spread, through blood or lymphatic circulation, to other organs and tissues of the body ( metastasis ).
What is an adenoma
An adenoma is a benign tumor that originates from epithelial cells of the exocrine glandular organs or from epithelial cells of tissues with secretory properties.
Examples of exocrine glandular organs are the breasts, the thyroid, the pituitary gland, the adrenal glands, the parathyroid gland and the prostate; examples of tissues with secretory properties, on the other hand, are the layers of mucosa that line the inner wall of the esophagus, stomach, colon or rectum.
What are epithelial cells?
Epithelial tissues constituting epithelial type cells are the cellular elements that cover the surfaces of all the external and internal structures of the human body, including cavities and glands.
ORIGIN OF THE NAME
The word "adenoma" has Greek origins and derives from the union of the terms "adenas" ( αδένας ), which means "gland" and refers to the glandular apparatus, and "oma" ( ώμα ), which means "tumor".
Therefore the literal meaning of adenoma is " glandular tumor " or " tumor of a gland ".
MALIGNO EQUIVALENT
The malignant equivalent of the adenoma (intended as a category of benign tumors) is adenocarcinoma .
Adenocarcinomas fall into the malignant tumor category of carcinomas . A carcinoma is any malignant neoplasm originating from an epithelial-type cell.
Carcinomas have a high infiltrating power and a marked metastatizing capacity: all this makes them conditions of poor prognosis, especially in the case of late diagnosis.
Returning to adenocarcinomas, these can sometimes derive from an adenoma. An adenoma that, quite frequently, assumes the characteristics of a malignant tumor is the adenoma of the colon : from this derives the so-called colorectal adenocarcinoma.
The most common adenocarcinomas:
- Colorectal adenocarcinoma
- Adenocarcinoma of the lung
- Adenocarcinoma of the breast
- Pancreatic adenocarcinoma
- Adenocarcinoma of the esophagus
- Adenocarcinoma of the prostate
Causes
The human body contains just over 37 trillion cells . These cells have a life cycle, which includes a growth phase, a division phase and a death phase.
The entire life cycle of a generic cell in the human body depends on the genetic heritage contained in the cell nucleus and known as DNA .
DNA is a highly efficient and precise "machine" capable of accurately directing and controlling all the most important phases of a cell's path from birth to death.
An adenoma (as well as all benign tumors and malignant tumors) arises as a result of irreparable damage to the DNA ( mutation ), which prevents the DNA from regulating the cellular processes of growth, division and death with precision and accuracy.
It follows that the cell or cells involved in the mutation of the genetic heritage grow and divide uncontrollably (there is also talk of uncontrolled cell proliferation ).
The cells of an adenoma - but in reality all the cells of a benign or malignant neoplasm - also take the name of " cells gone mad ": this terminology indicates precisely the anomaly that distinguishes them and the characteristic lack of control in the processes of growth and division.
A FEW DETAILS IN MORE THAN MUTATIONAL PROCESSES
To cause any adenoma - just like any other benign or malignant tumor - there is never a single DNA mutation, but a series of mutations .
Generally, the mutations that cause an adenoma, in a human being, appear at different times in life; in other words, the uncontrolled cellular proliferation, typical of adenomas, is the result of a slow accumulation of mutations, during the aging process.
The fact that the development of a benign or malignant tumor takes some time explains why patients are, except in special cases, middle-aged or elderly adults.
Young people with an adenoma or an adenocarcinoma (or any other type of tumor) are particularly unlucky individuals, because, for them, the accumulation of mutations has been very rapid.
Note well: the above described on the accumulation of mutations has particular value for malignant tumors. A malignant tumor is a classic example of a neoplastic process due to numerous mutational steps, which occur throughout life.
Curiosity: DNA has a defense system that corrects mutations
Among the various activities of human DNA, there is also that of generating proteins responsible for correcting the mutations that, in the course of life, affect the DNA itself. In other words, our genetic heritage has a system of self-defense against mutations.
This self-defense system is very effective; however, in some cases, it fails or makes mistakes and this involves the permanence of one or more mutations against the DNA.
In general, it is the errors of the defense system against mutations that lay the foundations for the development of malignant neoplasms.
Histopathology
Without going into too much detail, from the histological point of view it is important to point out that:
- An adenoma can present itself with different degrees of dysplasia . In fact, there are adenomas with low-grade dysplasia, adenomas with moderate-grade dysplasia and adenomas with high-grade dysplasia.
Remember that the term dysplasia indicates an abnormal cellular development of a tissue or organ. The dysplastic cells are cells that, with respect to their normal counterparts, are altered in shape and size, exhibit oddities at the level of the internal organelles and organize themselves in an anomalous manner.
- According to the characteristics of the epithelium, there are: trabecular or solid adenomas (for example: liver and adrenal glands), tubular adenomas, alveolar adenomas (for example: intestine, uterus, breasts, kidney and ovary) and follicular adenomas (for example: thyroid and ovary).
Types
The criterion used for distinguishing adenomas is the location of the tumor mass .
The best known human adenomas are:
- The adenoma of the colon
- Pituitary adenoma
- Thyroid adenoma
- Breast adenoma
- Renal adenoma
- Adrenal adenoma
- Parathyroid adenoma
- Hepatic adenoma
- Bronchial adenoma
- The sebaceous adenoma
- Adenoma of the salivary glands or pleomorphic adenoma.
ADENOMA OF THE COLON
The colon - the most important section of the large intestine - is the organ of the human body that most often develops adenomas.
Identified normally through a colonoscopy, adenoma of the colon is also known as an adenomatous polyp or intestinal polyp .
In general, doctors strongly advise surgical removal of intestinal polyps, as their transformation into adenocarcinomas is quite frequent.
According to a reliable statistical survey, 40% of people over the age of 60 have one or more adenomas of the colon.
To investigate the topic "adenomatous polyps in the intestine", the reader can consult the articles present here (overview on intestinal polyps), here (symptoms), here (video on causes, symptoms etc.) and here (drugs).
ADENOMA HYPOFISARIO
The pituitary adenoma originates from the cells of the pituitary gland, an endocrine gland located at the base of the skull (precisely below the diencephalic level) and responsible for the secretion of hormones that regulate numerous and important functions of the organism.
The formation of a pituitary adenoma can affect the functionality of the pituitary gland in two opposite ways:
- Increasing the activity of hormonal secretion;
- Blocking the release of hormones into the circulation.
In other words, therefore, pituitary adenomas have the ability to alter the production of hormones by the pituitary gland.
The size of a pituitary adenoma depends on the symptomatology: large pituitary adenomas are often associated with very marked symptoms (the tumor mass pushes onto nearby anatomical structures), while small pituitary adenomas can sometimes be completely asymptomatic (in these situations, their diagnosis happens by chance).
Generally, treatment of a pituitary adenoma involves drug therapy, radiation therapy and tumor removal surgery.
To know in detail the causes, symptoms and therapy of pituitary adenoma, readers can consult the articles present here (causes and symptoms) and here (therapy)
THYROIDAL ADENOMA
Thyroid adenoma, also known as thyroid nodule, is an adenoma originating from thyroid cells.
The thyroid is an unequal glandular organ, similar in shape to a butterfly, located in the anterior region of the neck, at the base of the throat.
Through the secretion of three hormones (triiodothyronine, thyroxine and calcitonin), the thyroid regulates very important physiological processes, including:
- Body metabolism
- Skeletal and cerebral development
- Protein synthesis
- The development of the skin, the piliferous apparatus and the genital organs
- The heartbeat
- Body temperature
- The hematopoiesis
Thyroid adenomas can be asymptomatic - therefore lacking associated symptoms - or they can cause hyperthyroidism and various compression effects (for example, if they compress the trachea, make breathing difficult etc.).
When a thyroid adenoma is symptomatic, doctors tend to recommend the intervention of thyroidectomy, which is the surgical operation aimed at removing a part of the thyroid.
To learn more about thyroid adenoma symptoms and therapy, readers can consult the article here (symptoms) and here (cure).
ADENOMA TO THE BREAST
Typical of women between the ages of 15 and 30, breast adenoma (or breast fibroadenoma ) is an adenoma that originates from the glandular tissue of the breasts, precisely from the so-called breast lobules .
On palpation, a breast adenoma can remind you of a lump or a ball. Its consistency varies from subject to subject: in some women, it is rubbery; in others, however, it is rigid.
There are two types of breast adenoma: the simple and the complex.
The simple breast adenoma is generally harmless, as it tends to remain stable throughout life.
In contrast, complex breast adenoma is a type of benign tumor that can evolve and become malignant. This explains why, in his presence, doctors advise periodic monitoring of the anomaly.
According to a reliable research carried out in the United States, 10% of US women develop breast adenomas every year.
Diagnosis
For a precise diagnosis of adenoma, biopsy is essential.
In fact, doctors are able to study in detail the cellular and molecular characteristics of the tumor mass and understand if it is a benign or malignant tumor.
An important parameter, which emerges from the biopsy and gives an idea of the severity of an adenoma, is the degree of dysplasia.
Prognosis
The prognosis of an adenoma depends on various factors, including: site, degree of dysplasia and malignant transformation.
