Carcinomas: Definition, Causes and Diagnosis

epithelial type constitute the epithelial tissues; epithelial tissues cover the surfaces of all external and internal structures of the human body, including cavities and glands.
Carcinomas are highly infiltrating and metastasizing malignant tumors.
Depending on the epithelial cell from which it originates, a carcinoma can be: a squamous cell carcinoma, an adenocarcinoma, a transitional cell carcinoma and a basal cell carcinoma.
A biopsy (or biopsy) is essential to diagnose cancer. From the biopsy, doctors are able to obtain information on the stage and grade of the malignancy.

What are epithelial cells: a brief review

Constituting the so-called epithelial tissue, epithelial-type cells are those cellular elements that line the external surface of the organs, including the glands, and the internal surface of most of the hollow organs (eg: larynx, stomach, intestine, bladder, etc.) .

(or cancer) that originates from the uncontrolled proliferation of an epithelial-type cell.

Which organs can a carcinoma affect?

Since they are all endowed with epithelial cells, organs such as skin, liver, kidneys, larynx, lungs, pancreas, breasts, prostate, stomach, intestines (duodenum, colon, sigma , rectum), bladder etc.

Main features of a Carcinoma?

Each carcinoma is a malignant neoplasm with good infiltrating and metastasizing power.
By infiltrating power (or infiltrating power), doctors mean the ability of a carcinoma to "affect" adjacent anatomical regions, making its way through other organs or tissue barriers.
With metastasizing power, on the other hand, they refer to the ability of the cells of a carcinoma to spread, through the blood or the lymphatic circulation, to other organs or tissues of the human body.

• The cells of carcinomas (and of malignant tumors in general) that contaminate organs and tissues distant from the site of tumor formation are called metastases.
• The process leading to the generation of metastases is known as metastasis.

Carcinoma is an Epithelioma

Carcinomas are malignant epitheliomas; in oncology, the term "epithelioma" refers to any tumor, benign or malignant, which originates from the abnormal proliferation of an epithelial cell.

For further information: Epithelioma

Origin of the name

The word carcinoma comes from the Greek word "karkinoma' (καρκίνωμα), which means "sore" or "ulcer".
"Karkinoma" in turn comes from "karkinos", which means "crab".

Epidemiology

The carcinoma understood as a category of malignant tumors represents the most common form of malignant neoplasm in the human being.
According to an Anglo-Saxon statistic, in fact, about 80-85 cases of cancer per 100 are carcinomas.

cellular and known as DNA. DNA is a highly efficient and precise machine, capable of accurately directing and controlling the phases of growth, division and death.

A carcinoma arises as a result of irreparable damage to the DNA (mutation), damage that prevents the DNA itself 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 in an uncontrolled way (we also speak of uncontrolled cell proliferation).
The cells of a carcinoma - but in reality all the cells of a malignant neoplasm - also take the name of "crazy cells": this term indicates precisely the anomaly that distinguishes them and the characteristic lack of control in the processes of growth and division.

A few more details on mutational processes

What causes any carcinoma - as well as any other malignant tumor - is never a single DNA mutation, but a series of mutations.
Generally, the mutations that cause a carcinoma, in a human being, appear at different times of life; in other words, the uncontrolled cell proliferation, typical of carcinomas, is the result of a slow accumulation of mutations during the aging process.
The slow accumulation of mutations over the course of life by those who develop cancer explains why patients are usually elderly. Young people with cancer are particularly unfortunate individuals, as the accumulation of the mutation has been very rapid for them.

Fun fact: DNA has a defense system that corrects mutations

Among the various activities of human DNA, there is also that of generating proteins, designed to correct the mutations that, in the course of life, affect the DNA itself. In other words, our genetic patrimony possesses 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 in the DNA.
It is generally errors on the part of the defense system against mutations that lay the foundation for the development of malignant neoplasms.

(or basalioma).

However, it should be noted that there is "another classification of carcinoma understood as a tumor category, based not only on the type of epithelial cell from which the tumor derives, but also on some of its characteristics developed after the appearance of the tumor; this second classification distinguishes 6 different ones. types of carcinoma:

• Adenocarcinoma (coincides with that of the other classification);
• Squamous cell carcinoma (coincides with that of the other classification);
• Adenosquamous carcinoma;
• Anaplastic carcinoma;
• Large cell carcinoma;
• Small cell carcinoma.

Squamous Carcinoma (or Spinalioma)

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Squamous carcinomas originate from the so-called squamous cells; the squamous cells are flat and characterize, above all, the outermost layers of the skin (precisely the epidermis) and the inner lining of organs such as the throat or the esophagus.
Examples of squamous cell carcinomas are some malignant tumors of the skin (squamous cell carcinoma), malignant tumors of the oral cavity (throat cancer, mouth cancer, tongue cancer, etc.) and some malignant tumors of the digestive system (tumors of the "esophagus, colon, rectum, etc.).

For further information: Squamous Carcinoma

Adenocarcinoma

Adenocarcinomas are carcinomas that originate from gland cells, such as the breasts or pancreas (N.B: in medicine, the prefix "adeno" indicates the glandular apparatus).
Examples of adenocarcinomas are malignant breast cancer, malignant pancreatic cancer, some cancers of the digestive system (colon and rectal cancers) and malignant prostate cancer.

For further information: Adenocarcinoma

Transitional Cell Carcinoma

Transitional cell carcinomas originate from the cells constituting the transition epithelia; the transitional epithelia are particular cellular formations, capable of stretching and endowed with impermeability. Generally, they localize in the urinary tract, covering the inner wall of the bladder or part of the urethra.
Examples of transitional cell carcinomas are malignant tumors of the urinary tract (bladder and urethra in particular).

Basal Cell Carcinoma (or Basalioma)

Basal cell carcinomas are carcinomas that arise from basal cells. The basal cells are cellular elements of cubic or cylindrical shape, located at the base of the epidermis, in direct contact with the underlying dermis.
The most classic of basal cell carcinomas is the skin basalioma.

For further information: Basal cell carcinoma

Other Types of Carcinoma

Adenosquamous Carcinoma

It consists of a carcinoma that contains both cancer cells from an adenocarcinoma and cancer cells from a squamous cell carcinoma.

Anaplastic Carcinoma

It is a carcinoma whose constituent tumor cells have undergone various histological and cytological alterations, so much so that it is difficult to understand its origin.
Anaplastic carcinomas are also called undifferentiated carcinomas.

Large Cell Carcinoma

It is a type of carcinoma characterized by enlarged cells, with a round or polygonal shape and with abundant cytoplasm.

Small Cell Carcinoma

It consists of a carcinoma whose tumor cells are round, small in size and with little cytoplasm.
Sometimes, cancer cells may appear polygonal and fusiform in shape.

Carcinoma In Situ

With the term carcinoma in situ, doctors intend an atypical proliferation of epithelial cells, which, despite some typical characteristics of malignant tumor cells, do not possess the same infiltrating and metastasizing power as the latter.
Carcinoma in situtherefore, it is a pre-cancerous tumor form, less dangerous than a real carcinoma and more easily treatable.

and radiotherapy are very effective.
Treatment can be complicated by a tumor mass located in a particularly inconvenient location to reach through medical-surgical instruments.

Stage II: all carcinomas between 2 and 5 centimeters in size and still limited to the area of ​​origin fall into stage II.
In general, stage II cancer is treatable with good results.
As in the previous case, a tumor mass formed in a particularly inconvenient point to reach through medical-surgical instruments can complicate the treatment.

Stage III: all carcinomas larger than 5 centimeters and which have invaded, with their malignant cells, the regional lymph nodes (ie those adjacent to the onset area) and some adjacent anatomical structures fall into stage III.
The chances of cure for stage III cancer are significantly lower than in the previous two cases (stage I and stage II). The difficulties of treatment are linked to the dispersion of malignant cells in the midst of healthy cells of the surrounding tissues and to the need to also remove the "contaminated" lymph nodes.

Stage IV: all those carcinomas which, regardless of size, have invaded the anatomical tissues adjacent to the area of ​​origin of the neoplasm and have disseminated metastases around the body are included in stage IV.
The chances of treatment for stage IV cancer are slim. Indeed, the removal of the tumor mass is remarkably complex and unsuccessful, as is the treatment of metastases.

In reality, the staging picture is somewhat more complex than that presented above "indeed. In fact, it would also include substages and a classification of metastases, linked to their presence / absence or their proximity / distance.

Degree

The grade of a malignant tumor, including carcinoma, includes all those data, collected during the biopsy examination, concerning the extent of transformation of the malignant tumor cells, compared to their healthy counterparts. In other words, it is an index of how much tumorigenesis (ie the formation of neoplasia) has affected the morphological aspect of the epithelial cells involved, modifying their original appearance.
By convention, doctors have established that there are 4 different grades, of increasing severity and identified with the Arabic numbers from 1 to 4:

• Grade 1: Grade 1 is a carcinoma whose malignant cells still closely resemble their healthy counterparts. This particular similarity allows doctors to easily determine the type of epithelial cell that gave rise to the neoplasm.
  Also known as well-differentiated carcinomas, Grade 1 carcinomas are the least severe and most easily treatable forms of cancer.
• Grade 2: Grade 2 is a carcinoma whose malignant cells, while still resembling their healthy counterparts, have some mild typical tumor characteristics, such as: irregularity in the shape and multi-layering of cells (at least 7 layers of superimposed cells).
  Also known as moderately differentiated carcinomas, Grade 2 carcinomas are forms of carcinoma of low to medium severity and with a good chance of cure.
• Grade 3: a carcinoma whose malignant cells bear little resemblance to their healthy counterparts, have a particularly irregular appearance, form numerous layers (more than 10) and have a moderate mitosis (mitosis = cell division) is grade 3.
  Also known as poorly differentiated carcinomas, grade 3 carcinomas are forms of carcinoma of medium to high severity and with little cure-all.
• Grade 4: Grade 4 is a carcinoma whose malignant cells no longer bear any resemblance to their healthy counterparts, are extremely disorganized and irregular in shape and possess a "high mitosis (ie they divide with high frequency).
  Also known as undifferentiated carcinomas, grade 4 carcinomas are the most severe and untreatable forms of cancer.

, with the intent of killing abnormal cells), chemotherapy (drugs that kill cells characterized by out-of-control growth, such as cancer) and targeted therapy (drugs that specifically counteract the growth of cancer cells).

Antonio Griguolo

Graduated in Biomolecular and Cellular Sciences, he obtained a Specialized Master in Journalism and Institutional Communication of Science