Histological examination is a morphological study of tissues and organs. It includes a biopsy and evaluation of the material obtained during surgery.
This study is carried out for diagnostic and therapeutic purposes. It is an important technique for detecting cancer, as well as a way to determine the effectiveness of the treatment.
To conduct a histological examination, they take the material and prepare it in a certain way for study. After that, thorough microscopy is used, as well as a qualitative and quantitative assessment of the obtained images.
The main object of analysis is histological preparations prepared from fixed structures. These include smears, prints, films of fabrics, as well as their thin sections.
For the manufacture of histological preparations, the necessary material is taken, fixed, compacted, sections prepared, stained or contrasted. These stages are preparations that are studied using electron microscopy. If the histological examination is carried out with a light orthoscope, then the obtained sections must still be enclosed in a balsam or other transparent medium.
To consider these drugs, various
types of microscopes are used
: light, transmission, scanning, electronic, ultraviolet and luminescent, as well as phase-contrast ones. The latter allow us to consider contrasting images of transparent objects that cannot be seen with conventional microscopy.
It is worth noting that when a histological examination is shown, the sampling of the material can take place under visual control (in the case of a biopsy of the skin or visible mucous membranes), as well as carried out by special methods (internal biopsy). So, tissues for research can be taken using a puncture needle, by aspiration, trepanation of the bone.
There is also the concept of targeted biopsy, when tissues for examination are taken under visual control when using special optical devices or using ultrasound.
It is worth noting that in order for the histological examination to give true results, the obtained material should be immediately delivered to the laboratory. If it is not possible to do this, the biopsy should be fixed with 10% formalin solution or 70% ethyl alcohol. If you need to conduct a pathomorphological study, then before fixing the material, smears for cytology must be done.
The pathologist who conducts the research first gives a macroscopic description of the material (indicates its size, color and consistency), and then applies the appropriate techniques to produce histological preparations. After that, he discovers microscopic changes, conducts a clinical anatomical analysis and draws conclusions.
In what cases are histological examination methods used?
Most often they are used to detect atypical cells and confirm cancer. Thus, a histological examination of the cervix allows the detection of a malignant tumor process in almost 95% of cases.
Analysis of histological preparations is also used in studies of moles, polyps of the stomach, various biomaterials. A histological examination of the fetus can also be used, which is prescribed for suspected hereditary pathologies.