Metaplasia refers to the transformation of a differentiated tissue into another differentiated tissue. It can be bone, intestinal, malpighian, Barrett’s… It is a phenomenon that can be natural, reversible and generally without danger.
A metaplasia is the transformation of a differentiated tissue into another of a different character, and which leads to the constitution of a normal tissue in itself, but abnormal by its location. We can speak of epithelial, fatty, bone, squamous, intestinal, progressive, absolute metaplasia… It’s what concretely a metaplasia? Is she reversible ? How heal her ?
“Metaplasia means transformation of one differentiated tissue into anotherto an abnormal localization of the body”, begins Dr. Romain Troalen, general practitioner in the Paris region. It responds to repeated and prolonged aggression, “which can be hormonal, chemical or tissue, such as inflammation, irritation or infection For example“, he specifies. To better understand : you should know that most tissues in the body are first stem cells (these cells can transform into any type of tissue), then they transform into differentiated cells, such as skin cells , eye, stomach… Metaplasia is therefore a phenomenon that may be normalbut this becomes potentially pathological and therefore dangerous depending on its location and the type of metaplasia. “A normal metaplasia manifests itself, for example, at the level of the cervix, at the time of puberty: the glandular epithelium of the cervix will transform into squamous epithelium.adds the doctor.
Yes, this phenomenon is adaptive and reversible.
It’s about a most common metaplasia. Exposure to tobacco or to an environment containing chemical vapors causes a transformation of the glandular epithelium of the bronchus into squamous epithelium. As the doctor explains, “metaplasia in this situation is not immediately dangerous, but there is a risk of appearance in the second stage of dysplasia, then in the last stage of lung cancer, also called squamous cell carcinoma“.
This metaplasia can be normal, but can also be dangerous“like the famous papillomavirus which will cause abnormal metaplasia in the cervix, which can later lead to cervical cancer“explains Doctor Romain Troalen. We are looking for this with screening smears, where we find different metaplasias. During the smears, it is a question of differentiating between normal metaplasias and those that show signs of the onset of cancer. .
As a reminder, the esophagus is the tube that goes from the mouth to the stomach. When there is gastroesophageal reflux (GERD), that is to say acid that rises in the lower part of the esophagus, this causes a chemical attack that can end up transforming the intestinal type epithelium in intestinal glandular it is called an endo-brachyoesophagus (also called Barrett’s esophagus). In some cases, the endo-brachyoesophagus can give rise to esophageal cancer.
Stomach metaplasia can occur when the stomach wall is attacked by stomach acids and bacteria Helicobacter pylori. It’s a bacteria that everyone has, but may not cause symptoms. It strongly favors ulcers and cancers of the stomach. “This is why, in the case of ulcers, regular monitoring is necessary to prevent metaplasia from setting in and risking the formation of cancer.“says the doctor.
In bone metaplasia, there are bone tissue in the uterusand this can cause secondary infertility. Usually it can happen following a miscarriage, abortion or childbirth. This leaves fragments of embryonic tissue in the uterus, which develops over time.
There are no specific symptoms. These are the symptoms of certain pathologies, which can reveal abnormal metaplasia. But it is difficult to define them without analyzing the nature of the problem.
► Ulcer: Gastric reflux has the effect of attacking the wall of the stomach. Thus the bacterium Helicobacter pylori, which everyone has naturally, proliferates and thus promotes ulceration of the stomach.
► Tobacco: Prolonged exposure to tobacco in the bronchi can cause metaplasia, transforming the glandular epithelium of the bronchus into squamous epithelium.
► GERD: Repeated gastroesophageal reflux attacks the wall of the esophagus. This risks transforming the intestinal type epithelium into intestinal glandular. This is called an endo-brachyesophagus.
The diagnosis is made based on the location of the metaplasia. For example, in the stomach, fibroscopy can be performed to see if there is anything wrong. Samples can then be performed to confirm the diagnosis.
Metaplasia cannot be treated strictly speaking, it is only necessary to eliminate all the factors which triggered it, for example tobacco for the bronchi, reflux for the esophagus. In the specific case of intestinal metaplasia, if it is due to the bacterium helicobacter pillory, it will take a antibiotic treatment to eliminate it. It is then necessary to monitor for some time, by regularly doing analyzes to check that everything is in order.
Thanks to Doctor Romain Troalen, general practitioner in the Paris region.